<span class=\"arrow\">→</span></a>\r\n <a class=\"comment-749331 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-749331\">\r\n </ul>\r\n</div>\r\n <br/>\r\n\r\n<div id=\"editBox-10513\" style=\"width:50em;display:none;\">\r\n <div class=\"previewBody\" style=\"border: 1px solid #d4d4d4; margin-bottom: 0.5em; padding: 0.25em; display:none;\"> </div>\r\n <div style=\"width: 1px\"> </div>\r\n <div class=\"commentLocale\" style=\"position: relative; top: 0.5em;left:4px;display: none;\">\r\n <input type=\"radio\" name=\"locale\" value=\"en\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In English</span>\r\n <input style=\"margin-left:1em\" type=\"radio\" name=\"locale\" value=\"ru\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In Russian</span>\r\n </div>\r\n <textarea data-drafts-id=\"CommentReplyFrame\" class=\"wysiwyg\" name=\"editContent\" rows=\"20\" style=\"width:99%;\"></textarea>\r\n <div class=\"error error__content\"></div>\r\n <div style=\"text-align:center;\">\r\n <input type=\"button\" name=\"preview\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Preview\"/>\r\n <input type=\"button\" name=\"save\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Save\"/>\r\n </div>\r\n</div>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n\r\nvar firstPreview10513 = true;\r\nvar lastPreviewContent10513 = '';\r\n\r\nif (!window.moveCommentRevision) {\r\n moveCommentRevision = function(e, dir) {\r\n var p = e.parent();\r\n var revisionCount = parseInt(p.attr(\"revisionCount\"));\r\n var revision = parseInt(p.attr(\"revision\"));\r\n var next = revision + dir;\r\n var commentId = p.attr(\"commentId\");\r\n if (next >= 1 && next <= revisionCount) {\r\n $.post(\r\n \"/data/comment-data\",\r\n {action: \"revision\", commentId: commentId, revision: next},\r\n function(json) {\r\n if (json.success == \"true\") {\r\n var parentDiv = e;\r\n\r\n while (parentDiv !== null && (parentDiv[0].nodeName.toLowerCase() !== \"td\" || !parentDiv.hasClass(\"right\"))) {\r\n parentDiv = parentDiv.parent();\r\n }\r\n\r\n if (parentDiv === null) {\r\n return;\r\n }\r\n\r\n parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\").html(json.content);\r\n Codeforces.setupSpoilers(parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\"));\r\n p.attr(\"revision\", next);\r\n p.find(\"span.revision\").text(next);\r\n if (next == 1) {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"visible\");\r\n }\r\n if (next == revisionCount) {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"visible\");\r\n }\r\n\r\n window.updateTypography();\r\n MathJax.Hub.Typeset();\r\n } else {\r\n alert(e.error);\r\n }\r\n },\r\n \"json\"\r\n );\r\n }\r\n };\r\n}\r\n\r\n$(\"div[commentableId=10513] a.leftRevision\").click(function () {\r\n window.moveCommentRevision($(this), -1);\r\n return false;\r\n});\r\n\r\n$(\"div[commentableId=10513] a.rightRevision\").click(function () {\r\n window.moveCommentRevision($(this), +1);\r\n return false;\r\n});\r\n\r\n\r\n\r\n });\n </script>\n\r\n\r\n <script src=\"//codeforces.org/s/81027/js/swfobject-2.2.min.js\" type=\"text/javascript\"></script>\n <script src=\"//codeforces.org/s/81027/js/ftaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n if (window.evercookie) {\n var ec = new evercookie({\n history: false,\n silverlight: false,\n baseurl: '',\n asseturi: '/assets',\n phpuri: '/2fdcd78',\n pngPath: '/eps',\n etagPath: '/ees',\n cachePath: '/ecs'\n });\n\n var randomNumber = function () {\n return Math.random().toString(36).substr(2);\n };\n\n var randomToken = function () {\n return (randomNumber() + randomNumber()).substring(0, 18);\n };\n\n window._ftaa = \"\";\n\n ec.get(\"70a7c28f3de\", function (value) {\n window._ftaa = value;\n if (!window._ftaa) {\n window._ftaa = randomToken();\n ec.set(\"70a7c28f3de\", window._ftaa);\n }\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n } else {\n window._ftaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\n <script src=\"//codeforces.org/s/81027/js/bfaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n var fpCallback = function() {\n Fingerprint2.get({}, function(components) {\n window._bfaa = Fingerprint2.x64hash128(components.map(function (pair) { return pair.value }).join(), 31);\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n };\n if (typeof Fingerprint2 !== 'undefined') {\n if (window.requestIdleCallback) {\n requestIdleCallback(fpCallback)\n } else {\n setTimeout(fpCallback, 500)\n }\n } else {\n window._bfaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"a.new-root-comment\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n\r\n $(\".comment-table .reply a\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".vote-for-comment\").mouseover(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").mouseout(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").click(function () {\r\n var vote = $(this);\r\n var commentId = $(this).parent().attr(\"commentid\");\r\n var commentRating = $(this).parent().attr(\"data-commentRating\");\r\n var direction = $(this).attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n $.post(\"/data/comment/vote\", {commentId: commentId, _tta: Codeforces.tta(), vote: direction, commentRating: commentRating}, function(data) {\r\n if (direction != 0 && !ownComment && data[\"success\"] == \"true\") {\r\n vote.parent().find(\".vote-for-comment\").attr(\"voteDirection\", 0);\r\n if (direction == 1)\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n else {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.closest(\".CommentVoteFrame\").find(\".ComplaintFrame\").css(\"display\", \"inline-block\");\r\n }\r\n vote.find(\"img\").attr(\"popacity\", \"1.0\");\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n vote.parent().find(\".commentRating\").html(data[\"commentRating\"]);\r\n }\r\n Codeforces.showMessage(data[\"message\"]);\r\n }, \"json\");\r\n return false;\r\n });\r\n\r\n $(\".negative-comment-vote\").closest(\".comment-table\").addClass(\"comment-bad\");\r\n\r\n $(\".troll-comment-vote\").closest(\".comment\").css(\"display\", \"none\");\r\n\r\n $(\".too-negative-comment-vote\").closest(\".comment-table\").each(function () {\r\n var e = $(this);\r\n e.addClass(\"comment-too-bad\");\r\n var commentId = e.attr(\"commentId\");\r\n $(\"<div class='bad-comment-replacement ttypography'>The comment is hidden because of too negative feedback, click <a href=# class=show-bad-comment-link>here</a> to view it</div>\").appendTo(\r\n e.find(\".right\")\r\n );\r\n e.find(\".comment-content\").hide();\r\n e.find(\".show-bad-comment-link\").click(function () {\r\n e.find(\".comment-content\").show();\r\n e.find(\".bad-comment-replacement\").hide();\r\n return false;\r\n });\r\n });\r\n });\n </script>\n </div>\r\n\r\n <style type=\"text/css\">\r\n .new-comments-box {\r\n padding: 0.5em;\r\n width: 22px;\r\n font-size: 1.3rem;\r\n font-weight: bold !important;\r\n\r\n position: fixed;\r\n top: 40%;\r\n right: 0;\r\n opacity: 0.2;\r\n color: white;\r\n text-align: center;\r\n\r\n border: 1px solid #222;\r\n background-color: #888 !important;\r\n border-radius: 3px;\r\n -moz-border-radius: 3px;\r\n -webkit-border-radius: 3px;\r\n }\r\n\r\n .new-comments-box:hover {\r\n opacity: 1;\r\n }\r\n\r\n .new-comments-box .dir:hover {\r\n background: #3B5998 !important;\r\n cursor: pointer;\r\n }\r\n </style>\r\n\r\n <div class=\"new-comments-box\" data-position=\"outside\" data-index=\"-1\" style=\"display: none;\">\r\n <div class=\"up dir\" title=\"Ctrl+Up\">↑<hr/>\r\n </div>\r\n <div class=\"info\" title=\"New comments\"></div>\r\n <div class=\"down dir\" title=\"Ctrl+Down\">\r\n <hr/>↓\r\n </div>\r\n </div>\r\n\r\n <script>\r\n $(\".show-archived-checkbox\").change(function () {\r\n const checked = $(this).is(\":checked\");\r\n $.post(\"/data/comment-data\", {action: \"setShowArchived\", checked}, function (json) {\r\n if (json[\"success\"] !== \"true\") {\r\n alert(json[\"error\"]);\r\n } else {\r\n if (checked) {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are now displayed\")\r\n } else {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are no longer displayed\")\r\n }\r\n }\r\n });\r\n return false;\r\n });\r\n\r\n function gotoComment(direction) {\r\n var box = $(\".new-comments-box\");\r\n var index = parseInt(box.attr(\"data-index\"));\r\n if (index == -1)\r\n index = 0;\r\n else\r\n index = Math.max(0, Math.min(parseInt(box.find(\".info\").text()) - 1, index + direction));\r\n box.attr(\"data-index\", index);\r\n var comment = $($(\".comment .highlight-blue[commentId]\").get(index));\r\n $('html, body').animate({\r\n 'scrollTop': Math.max(0, comment.offset().top - ($(window).height() - comment.height()) / 2)\r\n });\r\n return false;\r\n }\r\n\r\n $(\".new-comments-box .down\").click(function () {\r\n return gotoComment(1);\r\n });\r\n\r\n $(\".new-comments-box .up\").click(function () {\r\n return gotoComment(-1);\r\n });\r\n\r\n $(document).keydown(function (e) {\r\n var code = (e.keyCode ? e.keyCode : e.which);\r\n if (e.ctrlKey) {\r\n if (code == 38 || code == 40) {\r\n gotoComment(code - 39);\r\n }\r\n }\r\n });\r\n\r\n var newCommentCount = $(\".comment .highlight-blue[commentId]\").length;\r\n if (newCommentCount > 0) {\r\n $(\".new-comments-box .info\").text(newCommentCount);\r\n $(\".new-comments-box\").show();\r\n }\r\n\r\n $('table.comment-table').mouseenter(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").addClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n\r\n $('table.comment-table').mouseleave(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").removeClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n </script>\r\n\r\n\r\n\r\n <script>\r\n function adjustTopicComplainFrames() {\r\n let topicIds = [];\r\n\r\n $(\".has-topic-id\").each(function () {\r\n const $this = $(this);\r\n const topicId = $this.attr(\"topicId\");\r\n if (topicId) {\r\n topicIds.push(topicId);\r\n }\r\n });\r\n\r\n $.post(\"/data/topics\", {\r\n action: \"findComplainableTopicIds\",\r\n topicIds: topicIds.join(\",\")\r\n }, function (json) {\r\n if (json[\"success\"] === \"true\") {\r\n for (const topicId of json[\"complainableTopicIds\"].split(\",\")) {\r\n $(\".has-topic-id[topicId=\" + topicId + \"]\").each(function () {\r\n $(this).find(\".meta .ComplaintFrame\").css(\"display\", \"inline-block\");\r\n });\r\n }\r\n }\r\n }, \"json\");\r\n }\r\n\r\n $(function () {\r\n adjustTopicComplainFrames();\r\n })\r\n </script>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-10497\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 10497, _tta: Codeforces.tta(), topicRevisionId: 36230, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-10497\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 10497, _tta: Codeforces.tta(), topicRevisionId: 36230, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n </div>\r\n </div>\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 22:13:00</span> (h1).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/81027/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/81027/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/81027/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/81027/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-81027.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'8128757a3bdb76a9',t:'MTY5NjcwNTk4MC43NTcwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"}}},{"rowIdx":1934,"cells":{"problem_id":{"kind":"string","value":"383A"},"contest":{"kind":"string","value":"383"},"problem":{"kind":"string","value":"A"},"lang":{"kind":"string","value":"en"},"problem_title":{"kind":"string","value":"A. Milking cows"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">A. Milking cows</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Iahub helps his grandfather at the farm. Today he must milk the cows. There are <span class=\"tex-span\"><i>n</i></span> cows sitting in a row, numbered from <span class=\"tex-span\">1</span> to <span class=\"tex-span\"><i>n</i></span> from left to right. Each cow is either facing to the left or facing to the right. When Iahub milks a cow, all the cows that see the current cow get scared and lose one unit of the quantity of milk that they can give. A cow facing left sees all the cows with lower indices than her index, and a cow facing right sees all the cows with higher indices than her index. A cow that got scared once can get scared again (and lose one more unit of milk). A cow that has been milked once cannot get scared and lose any more milk. You can assume that a cow never loses all the milk she can give (a cow gives an infinitely amount of milk).</p><p>Iahub can decide the order in which he milks the cows. But he must milk each cow exactly once. Iahub wants to lose as little milk as possible. Print the minimum amount of milk that is lost.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains an integer <span class=\"tex-span\"><i>n</i></span> <span class=\"tex-span\">(1 ≤ <i>n</i> ≤ 200000)</span>. The second line contains <span class=\"tex-span\"><i>n</i></span> integers <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub></span>, <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">2</sub></span>, ..., <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>n</i></sub></span>, where <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> is <span class=\"tex-span\">0</span> if the cow number <span class=\"tex-span\"><i>i</i></span> is facing left, and <span class=\"tex-span\">1</span> if it is facing right.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print a single integer, the minimum amount of lost milk.</p><p>Please, do not write the <span class=\"tex-font-style-tt\">%lld</span> specifier to read or write 64-bit integers in С++. It is preferred to use the <span class=\"tex-font-style-tt\">cin</span>, <span class=\"tex-font-style-tt\">cout</span> streams or the <span class=\"tex-font-style-tt\">%I64d</span> specifier.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>4<br/>0 0 1 0<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1</pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>5<br/>1 0 1 0 1<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>3</pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>In the first sample Iahub milks the cows in the following order: cow <span class=\"tex-span\">3</span>, cow <span class=\"tex-span\">4</span>, cow <span class=\"tex-span\">2</span>, cow <span class=\"tex-span\">1</span>. When he milks cow <span class=\"tex-span\">3</span>, cow <span class=\"tex-span\">4</span> loses <span class=\"tex-span\">1</span> unit of milk. After that, no more milk is lost.</p></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"6ced0ee7f201b1d20caae2a9e1f0d1a6\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - A - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"f2f8284d26a4a4d6b4f15082f9e1ab3f212e9edd\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - A - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/73366/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/73366/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/73366/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/73366/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/73366/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/73366/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/73366/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/73366/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/73366/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/73366/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/73366/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/73366/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/73366/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/73366/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/sidebar-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/a037fe51637846d9c7c725713cd840ea/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='6ced0ee7f201b1d20caae2a9e1f0d1a6'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/73366/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/73366/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fcontest%2F383%2Fproblem%2FA%3Flocale%3Den\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"current\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='6ced0ee7f201b1d20caae2a9e1f0d1a6'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:100%;\"><a style=\"color: black\" href=\"/contest/383\">Codeforces Round 225 (Div. 1)</a></th>\n </tr>\n <tr>\n <td class=\"left bottom\" colspan=\"1\"><span class=\"contest-state-phase\">Finished</span></td>\n </tr>\n </tbody>\n </table>\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Practice?\n <div class=\"top-links\">\n </div>\n </div>\n<div>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Want to solve the contest problems after the official contest ends? Just register for practice and you will be able to submit solutions.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"\" method=\"post\"><input type='hidden' name='csrf_token' value='6ced0ee7f201b1d20caae2a9e1f0d1a6'/>\r\n <input type=\"hidden\" name=\"action\" value=\"registerForPractice\"/>\r\n <input type=\"submit\" name=\"submit\" value=\"Register for practice\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div> \r\n</div>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox ContestVirtualFrame borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Virtual participation <i class=\"sidebar-caption-icon las la-angle-down\"></i>\r\n\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\" \"\r\n\r\n data-page-url=\"/data/sidebarFrames\"\r\n\r\n>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests.\n\nIf you've seen these problems, a virtual contest is not for you - solve these problems in the archive.\n\nIf you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.\n\nNever use someone else's code, read the tutorials or communicate with other person during a virtual contest.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"/contest/383/virtual\" method=\"get\">\r\n <input type=\"submit\" name=\"submit\" value=\"Start virtual contest\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div>\r\n</div>\r\n <script>\r\n $(function () {\r\n $(\".ContestVirtualFrame .sidebar-caption-icon\").click(function() {\r\n $(this).toggleClass(\"la-angle-down la-angle-right\");\r\n const $target = $(this).parent().next();\r\n $target.toggle();\r\n const dataPageUrl = $target.attr(\"data-page-url\");\r\n const collapsed = $(this).hasClass(\"la-angle-right\");\r\n const params = {\r\n action: \"setCollapsed\",\r\n sidebarFrameSimpleClassName: \"ContestVirtualFrame\",\r\n collapsed\r\n };\r\n $.each($target[0].attributes, function(i, a) {\r\n const name = a.name;\r\n if (name.startsWith(\"data-extra-key-\")) {\r\n const key = a.value;\r\n const keyIndex = parseInt(name.substring(\"data-extra-key-\".length));\r\n const value = $target.attr(\"data-extra-value-\" + keyIndex);\r\n params[key] = value;\r\n }\r\n });\r\n $.post(dataPageUrl, params, function (result) {\r\n if (result[\"success\"] !== \"true\") {\r\n Codeforces.showMessage(\"Failed to save collapsed state.\");\r\n }\r\n }, \"json\");\r\n return false;\r\n });\r\n })\r\n </script>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Problem tags\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Heaps, binary search trees, segment trees, hash tables, etc\">\r\n data structures\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Greedy algorithms\">\r\n greedy\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Difficulty\">\r\n *1600\r\n</span>\r\n </div>\n <div style=\"clear:both;text-align:right;font-size:1.1rem;\">\r\n <span title=\"Please login into the Codeforces\" class=\"notice\">No tag edit access</span>\r\n </div>\r\n</div>\r\n </div>\n\r\n<form id=\"addTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='6ced0ee7f201b1d20caae2a9e1f0d1a6'/>\r\n <input name=\"action\" type=\"hidden\" value=\"addTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"5722\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<form id=\"removeTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='6ced0ee7f201b1d20caae2a9e1f0d1a6'/>\r\n <input name=\"action\" type=\"hidden\" value=\"removeTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"5722\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<script type=\"text/javascript\">\r\n $(\".tag-box img\").click(function () {\r\n var tagName = $(this).attr(\"value\");\r\n Codeforces.confirm(\"Are you sure you want to remove this tag?\", function () {\r\n $(\"#removeTagForm input[name=tagName]\").val(tagName);\r\n $(\"#removeTagForm\").submit();\r\n }, function () {\r\n }, \"Yes\", \"No\");\r\n });\r\n\r\n $(\"#addTagLink\").click(function () {\r\n $(this).hide();\r\n $(\"#addTagLabel\").show();\r\n return false;\r\n });\r\n\r\n $(\"#addTagSelect\").change(function () {\r\n var tagName = $(this).val();\r\n if (tagName === \"\") {\r\n $(\"#addTagLabel\").hide();\r\n $(\"#addTagLink\").show();\r\n } else {\r\n $(\"#addTagForm input[name=tagName]\").val(tagName);\r\n $(\"#addTagForm\").submit();\r\n }\r\n });\r\n</script>\r\n\r\n<style type=\"text/css\">\r\n#new-resource-form tr td {\r\npadding-top: 0.5em;\r\n}\r\n#new-resource-form input:not([type=\"submit\"]) {\r\nfont-size: 0.8em;\r\n}\r\n#new-resource-form select {\r\nfont-size: 0.8em;\r\n}\r\n.new-resource-error {\r\nfont-size: 0.8em;\r\n}\r\n.resource-locale {\r\ncolor: #666;\r\nfont-family: Consolas, \"Andale Mono WT\", \"Andale Mono\", \"Lucida Console\", \"Lucida Sans Typewriter\", \"DejaVu Sans Mono\", \"Bitstream Vera Sans Mono\", \"Liberation Mono\", \"Nimbus Mono L\", Monaco, \"Courier New\", Courier, monospace;\r\n}\r\n</style>\r\n<div class=\"roundbox sidebox sidebar-menu borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Contest materials\n<div class=\"top-links\">\n</div>\n</div>\n<ul>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/10448\" title=\"Codeforces Round #225\" target=\"_blank\">Codeforces Round #225</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"2166:2167\" resourceName=\"Announcement\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n<li>\r\n<span>\r\n<a href=\"https://codeforces.com/blog/entry/10476\" title=\"Tutorial\" target=\"_blank\">Tutorial <span class=\"resource-locale\">(en)</span></a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"2170\" resourceName=\"Tutorial\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n</ul>\r\n</div></div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li class=\"current selectedLava\"><a\r\n href=\"/contest/383\">Problems</a></li>\r\n <li><a\r\n href=\"/contest/383/submit\">Submit Code</a></li>\r\n <li><a\r\n href=\"/contest/383/my\">My Submissions</a></li>\r\n <li><a\r\n href=\"/contest/383/status\">Status</a></li>\r\n <li><a\r\n href=\"/contest/383/hacks\">Hacks</a></li>\r\n <li><a\r\n href=\"/contest/383/room/1\">Room</a></li>\r\n <li><a\r\n href=\"/contest/383/standings\">Standings</a></li>\r\n <li><a\r\n href=\"/contest/383/customtest\">Custom Invocation</a></li>\r\n</ul>\r\n</div>\n\r\n <style>\r\n #facebox .content:has(.diff-popup) {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n }\r\n\r\n .testCaseMarker {\r\n position: absolute;\r\n font-weight: bold;\r\n font-size: 1rem;\r\n }\r\n\r\n .diff-popup {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n display: none;\r\n overflow: auto;\r\n }\r\n\r\n .input-output-copier {\r\n font-size: 1.2rem;\r\n float: right;\r\n color: #888 !important;\r\n cursor: pointer;\r\n border: 1px solid rgb(185, 185, 185);\r\n padding: 3px;\r\n margin: 1px;\r\n line-height: 1.1rem;\r\n text-transform: none;\r\n }\r\n\r\n .input-output-copier:hover {\r\n background-color: #def;\r\n }\r\n\r\n .test-explanation textarea {\r\n width: 100%;\r\n height: 1.5em;\r\n }\r\n\r\n .pending-submission-message {\r\n color: darkorange !important;\r\n }\r\n </style>\r\n <script>\r\n const OPENING_SPACE = String.fromCharCode(1001);\r\n const CLOSING_SPACE = String.fromCharCode(1002);\r\n\r\n const nodeToText = function (node, pre) {\r\n let result = [];\r\n\r\n if (node.tagName === \"SCRIPT\" || node.tagName === \"math\"\r\n || (node.classList && node.classList.contains(\"input-output-copier\")))\r\n return [];\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(OPENING_SPACE);\r\n }\r\n\r\n if (node.nodeType === Node.TEXT_NODE) {\r\n let s = node.textContent;\r\n if (!pre) {\r\n s = s.replace(/\\s+/g, \" \");\r\n }\r\n if (s.length > 0) {\r\n result.push(s);\r\n }\r\n }\r\n\r\n if (pre && node.tagName === \"BR\") {\r\n result.push(\"\\n\");\r\n }\r\n\r\n node.childNodes.forEach(function (child) {\r\n result.push(nodeToText(child, node.tagName === \"PRE\").join(\"\"));\r\n });\r\n\r\n if (node.tagName === \"DIV\"\r\n || node.tagName === \"P\"\r\n || node.tagName === \"PRE\"\r\n || node.tagName === \"UL\"\r\n || node.tagName === \"LI\"\r\n ) {\r\n result.push(\"\\n\");\r\n }\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(CLOSING_SPACE);\r\n }\r\n\r\n return result;\r\n }\r\n\r\n const isSpecial = function (c) {\r\n return c === ',' || c === '.' || c === ';' || c === ')' || c === ' ';\r\n }\r\n\r\n const convertStatementToText = function(statmentNode) {\r\n const text = nodeToText(statmentNode, false).join(\"\").replace(/ +/g, \" \").replace(/\\n\\n+/g, \"\\n\\n\");\r\n let result = [];\r\n for (let i = 0; i < text.length; i++) {\r\n const c = text.charAt(i);\r\n if (c === OPENING_SPACE) {\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"A\" data-uuid=\"ps_266c909a9c37edd17ef89b5255ea06cc171f1dda\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">A. Milking cows</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Iahub helps his grandfather at the farm. Today he must milk the cows. There are <span class=\"tex-span\"><i>n</i></span> cows sitting in a row, numbered from <span class=\"tex-span\">1</span> to <span class=\"tex-span\"><i>n</i></span> from left to right. Each cow is either facing to the left or facing to the right. When Iahub milks a cow, all the cows that see the current cow get scared and lose one unit of the quantity of milk that they can give. A cow facing left sees all the cows with lower indices than her index, and a cow facing right sees all the cows with higher indices than her index. A cow that got scared once can get scared again (and lose one more unit of milk). A cow that has been milked once cannot get scared and lose any more milk. You can assume that a cow never loses all the milk she can give (a cow gives an infinitely amount of milk).</p><p>Iahub can decide the order in which he milks the cows. But he must milk each cow exactly once. Iahub wants to lose as little milk as possible. Print the minimum amount of milk that is lost.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains an integer <span class=\"tex-span\"><i>n</i></span> <span class=\"tex-span\">(1 ≤ <i>n</i> ≤ 200000)</span>. The second line contains <span class=\"tex-span\"><i>n</i></span> integers <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub></span>, <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">2</sub></span>, ..., <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>n</i></sub></span>, where <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> is <span class=\"tex-span\">0</span> if the cow number <span class=\"tex-span\"><i>i</i></span> is facing left, and <span class=\"tex-span\">1</span> if it is facing right.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print a single integer, the minimum amount of lost milk.</p><p>Please, do not write the <span class=\"tex-font-style-tt\">%lld</span> specifier to read or write 64-bit integers in С++. It is preferred to use the <span class=\"tex-font-style-tt\">cin</span>, <span class=\"tex-font-style-tt\">cout</span> streams or the <span class=\"tex-font-style-tt\">%I64d</span> specifier.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>4<br />0 0 1 0<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1</pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>5<br />1 0 1 0 1<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>3</pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>In the first sample Iahub milks the cows in the following order: cow <span class=\"tex-span\">3</span>, cow <span class=\"tex-span\">4</span>, cow <span class=\"tex-span\">2</span>, cow <span class=\"tex-span\">1</span>. When he milks cow <span class=\"tex-span\">3</span>, cow <span class=\"tex-span\">4</span> loses <span class=\"tex-span\">1</span> unit of milk. After that, no more milk is lost.</p></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=A]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== statementText) {\r\n $problem.find(\".diff-notifier\").show();\r\n\r\n $problem.find(\".diff-notifier-close\").click(function() {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n $problem.find(\".diff-notifier\").hide();\r\n });\r\n\r\n $problem.find(\"a.view-changes\").click(function() {\r\n $.post(\"/data/diff\", {action: \"getDiff\", a: previousStatementText, b: statementText}, function (result) {\r\n if (result[\"success\"] === \"true\") {\r\n Codeforces.facebox(\".diff-popup\", \"//codeforces.org/s/73366\");\r\n $(\"#facebox .diff-popup\").html(result[\"diff\"]);\r\n }\r\n }, \"json\");\r\n });\r\n }\r\n } else {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n }\r\n });\r\n });\r\n </script>\r\n\r\n\r\n<script type=\"text/javascript\">\r\n $(document).ready(function () {\r\n window.changedTests = new Set();\r\n\r\n function endsWith(string, suffix) {\r\n return string.indexOf(suffix, string.length - suffix.length) !== -1;\r\n }\r\n\r\n const inputFileDiv = $(\"div.input-file\");\r\n const inputFile = inputFileDiv.text();\r\n const outputFileDiv = $(\"div.output-file\");\r\n const outputFile = outputFileDiv.text();\r\n\r\n\r\n if (!endsWith(inputFile, \"standard input\")\r\n && !endsWith(inputFile, \"standard input\")) {\r\n inputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n if (!endsWith(outputFile, \"standard output\")\r\n && !endsWith(outputFile, \"standard output\")) {\r\n outputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n const titleDiv = $(\"div.header div.title\");\r\n\r\n\r\n\r\n String.prototype.replaceAll = function (search, replace) {\r\n return this.split(search).join(replace);\r\n };\r\n\r\n $(\".sample-test .title\").each(function () {\r\n const preId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n const cpyId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n\r\n $(this).parent().find(\"pre\").attr(\"id\", preId);\r\n const $copy = $(\"<div title='Copy' data-clipboard-target='#\" + preId + \"' id='\" + cpyId + \"' class='input-output-copier'>Copy</div>\");\r\n $(this).append($copy);\r\n\r\n const clipboard = new Clipboard('#' + cpyId, {\r\n text: function (trigger) {\r\n const pre = document.querySelector('#' + preId);\r\n const lines = pre.querySelectorAll(\".test-example-line\");\r\n return Codeforces.filterClipboardText(pre.innerText, lines.length);\r\n }\r\n });\r\n\r\n const isInput = $(this).parent().hasClass(\"input\");\r\n\r\n clipboard.on('success', function (e) {\r\n if (isInput) {\r\n Codeforces.showMessage(\"The example input has been copied into the clipboard\");\r\n } else {\r\n Codeforces.showMessage(\"The example output has been copied into the clipboard\");\r\n }\r\n e.clearSelection();\r\n });\r\n });\r\n\r\n $(\".test-form-item input\").change(function () {\r\n addPendingSubmissionMessage($($(this).closest(\"form\")), \"You changed the answer, do not forget to submit it if you want to save the changes\");\r\n const index = $(this).closest(\".problemindexholder\").attr(\"problemindex\");\r\n let test = \"\";\r\n $(this).closest(\"form input\").each(function () {\r\n const test_ = $(this).attr(\"name\");\r\n if (test_ && test_.substring(0, 4) === \"test\") {\r\n test = test_;\r\n }\r\n });\r\n if (index.length > 0 && test.length > 0) {\r\n const indexTest = index + \"::\" + test;\r\n window.changedTests.add(indexTest);\r\n }\r\n });\r\n\r\n $(window).on('beforeunload', function () {\r\n if (window.changedTests.size > 0) {\r\n return 'Dialog text here';\r\n }\r\n });\r\n\r\n autosize($('.test-explanation textarea'));\r\n\r\n $(\".test-example-line\").hover(function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n let top = 1E20;\r\n let left = 1E20;\r\n let problem = $(this).closest(\".problemindexholder\");\r\n $(this).closest(\".input\").find(\".\" + clazz).css(\"background-color\", \"#FFFDE7\").each(function() {\r\n top = Math.min(top, $(this).offset().top);\r\n left = Math.min(left, $(this).offset().left);\r\n });\r\n let testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n if (testCaseMarker.length === 0) {\r\n const html = \"<div class=\\\"testCaseMarker testCaseMarker_\" + end + \" notice\\\"></div>\";\r\n problem.append($(html));\r\n testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n }\r\n if (testCaseMarker) {\r\n testCaseMarker.show()\r\n .offset({top, left: left - 20})\r\n .text(end);\r\n }\r\n }\r\n }\r\n });\r\n }, function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n $(\".\" + clazz).css(\"background-color\", \"\");\r\n $(this).closest(\".problemindexholder\").find(\".testCaseMarker_\" + end).hide();\r\n }\r\n }\r\n });\r\n });\r\n\r\n });\r\n</script>\r\n\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 05:37:57</span> (j3).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/73366/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/73366/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/73366/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/73366/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-73366.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'8122c3e04cdc7a75',t:'MTY5NjY0NjI3Ny4zNTIwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"},"long_tags":{"kind":"string","value":"[\"Heaps, binary search trees, segment trees, hash tables, etc\", \"Greedy algorithms\"]"},"short_tags":{"kind":"string","value":"[\"data structures\", \"greedy\", \"*1600\"]"},"tutorial_link":{"kind":"string","value":"https://codeforces.com/blog/entry/10476"},"tutorial_page":{"kind":"string","value":"\r\n\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"4f4c31ed5807bbee2a02378cf0944c06\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"h1\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Codeforces Round #225 — Editorial - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n \n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Codeforces Round #225 — Editorial - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/81027/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/81027/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/81027/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/81027/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/81027/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/81027/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/81027/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/81027/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/81027/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/81027/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/81027/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/81027/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/81027/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/81027/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/573cedc6b04c15481941f418269f4057/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='4f4c31ed5807bbee2a02378cf0944c06'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/81027/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fblog%2Fentry%2F10476\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='4f4c31ed5807bbee2a02378cf0944c06'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Pay attention\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n <div style=\"text-align:center;border-bottom: 1px solid rgb(185, 185, 185);margin:0 -0.5em 0.5em -0.5em;padding: 0 1em 0.5em 1em;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 1, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:51:58</span><br/><a href=\"/contestRegistration/1876\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n <div style=\"text-align:center;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 2, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:51:58</span><br/><a href=\"/contestRegistration/1877\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n\r\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div>\r\n\r\n\n <div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\n\r\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='4f4c31ed5807bbee2a02378cf0944c06'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n </label>\r\n </div>\r\n <div style=\"padding: 0 1em 1em 1em;text-align:right;\">\r\n <input style=\"height:1.65em;padding:0 0.75em;\" type=\"submit\" value=\"Find\"/>\r\n </div>\r\n </form>\r\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".handleBox\").autocomplete(\"/data/handles\", {\r\n delay: 200,\r\n width: 200,\r\n selectFirst: false,\r\n matchContains: true,\r\n minChars: 3\r\n });\r\n $(\".handleForm\").attr(\"autocomplete\", \"off\").submit(function () {\r\n var link = \"/profile/userHandle\".replace(\r\n \"userHandle\", $(this).find(\".handleBox\").val()\r\n );\r\n window.location = link;\r\n return false;\r\n });\r\n });\n </script>\n\r\n\r\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Recent actions\n <div class=\"top-links\">\n </div>\n </div>\n <div class=\"recent-actions\">\r\n <ul>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/121073\">Meta Hacker Cup 2023 Round 1</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/.Danet\" title=\"Expert .Danet\" class=\"rated-user user-blue\">.Danet</a> →\r\n <a href=\"/blog/entry/121172\">[TLE on pretest1]</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\" class=\"rated-user user-red\">Pyqe</a> →\r\n <a href=\"/blog/entry/121025\">Codeforces Round #902 (Div. 1, Div. 2, based on COMPFEST 15 — Final Round)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pranshu_Pandya\" title=\"Specialist Pranshu_Pandya\" class=\"rated-user user-cyan\">Pranshu_Pandya</a> →\r\n <a href=\"/blog/entry/121171\">An Interesting Tree Problem</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/sszcdjr\" title=\"Master sszcdjr\" class=\"rated-user user-orange\">sszcdjr</a> →\r\n <a href=\"/blog/entry/119859\">Codeforces Round 896 (Div. 1, Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/119880\">It's Happening! Meta Hacker Cup 2023 Schedule</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/DaviddeGea1\" title=\"Expert DaviddeGea1\" class=\"rated-user user-blue\">DaviddeGea1</a> →\r\n <a href=\"/blog/entry/70917\">Number of ways of dividing an array into 2 parts such that sum of each part is > k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bekh\" title=\"Master Bekh\" class=\"rated-user user-orange\">Bekh</a> →\r\n <a href=\"/blog/entry/74245\">Questions and doubts regarding Aliens DP trick</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a> →\r\n <a href=\"/blog/entry/8192\">Codeforces Round #190 — Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/hocky\" title=\"Candidate Master hocky\" class=\"rated-user user-violet\">hocky</a> →\r\n <a href=\"/blog/entry/95323\">FBHC wuining uw Day? Incwease uw stacc size! (ㅅ´ ˘ `)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/liouzhou_101\" title=\"International Master liouzhou_101\" class=\"rated-user user-orange\">liouzhou_101</a> →\r\n <a href=\"/blog/entry/87598\">Editorial of Codeforces Round #700</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/yeon_gist\" title=\"Newbie yeon_gist\" class=\"rated-user user-gray\">yeon_gist</a> →\r\n <a href=\"/blog/entry/121170\">plusMinusPermutation computing error</a>\r\n <img alt=\"Text created or updated\" title=\"Text created or updated\" src=\"//codeforces.org/s/81027/images/icons/x-update-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/altforminuscontribution\" title=\"Newbie altforminuscontribution\" class=\"rated-user user-gray\">altforminuscontribution</a> →\r\n <a href=\"/blog/entry/121162\">My screen get unexpectedly big, what should I do</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/atcoder_official\" title=\"Unrated, atcoder_official\" class=\"rated-user user-black\">atcoder_official</a> →\r\n <a href=\"/blog/entry/121120\">We will hold UNIQUE VISION Programming Contest 2023 Autumn(AtCoder Beginner Contest 323)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/YouStill_DontKnowMeYet\" title=\"Candidate Master YouStill_DontKnowMeYet\" class=\"rated-user user-violet\">YouStill_DontKnowMeYet</a> →\r\n <a href=\"/blog/entry/117659\">[GYM] Al-Baath Collegiate Programming Contest 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/ankancool\" title=\"Expert ankancool\" class=\"rated-user user-blue\">ankancool</a> →\r\n <a href=\"/blog/entry/121136\">Invitation to AstroByte 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/GeZhiyuan\" title=\"Grandmaster GeZhiyuan\" class=\"rated-user user-red\">GeZhiyuan</a> →\r\n <a href=\"/blog/entry/120943\">Codeforces Round 901 (Div. 1, Div. 2) Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a> →\r\n <a href=\"/blog/entry/120772\">PSA: Increase your stack size before the Meta Hacker Cup, here's how</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/dino_merlin\" title=\"Expert dino_merlin\" class=\"rated-user user-blue\">dino_merlin</a> →\r\n <a href=\"/blog/entry/121145\">Intuitive approach for CEOI Kangaroo?</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/icecuber\" title=\"Grandmaster icecuber\" class=\"rated-user user-red\">icecuber</a> →\r\n <a href=\"/blog/entry/70018\">CSES DP section editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bn00b\" title=\"Newbie Bn00b\" class=\"rated-user user-gray\">Bn00b</a> →\r\n <a href=\"/blog/entry/98820\">[FEATURE REQUEST : ATCODER] TOPICS TAGS AND SORTING BY SOLVE COUNT</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a> →\r\n <a href=\"/blog/entry/121163\">AtCoder Regular Contest 166 Announcement</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/windva\" title=\"Grandmaster windva\" class=\"rated-user user-red\">windva</a> →\r\n <a href=\"/blog/entry/120644\">Codeforces Round 899 (Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Misa-Misa\" title=\"Expert Misa-Misa\" class=\"rated-user user-blue\">Misa-Misa</a> →\r\n <a href=\"/blog/entry/121157\">Someone please help me understand this.</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/shivam565\" title=\"Specialist shivam565\" class=\"rated-user user-cyan\">shivam565</a> →\r\n <a href=\"/blog/entry/108348\">Total number of subarrays with sum atmost k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n </ul>\r\n </div>\r\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/recent-actions\">Detailed →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n</div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li><a\r\n href=\"/profile/fchirica\">fchirica</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/fchirica\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/fchirica\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/fchirica\">Submissions</a></li>\r\n <li><a\r\n href=\"/groups/with/fchirica\">Groups</a></li>\r\n <li><a\r\n href=\"/contests/with/fchirica\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/fchirica\">Problemsetting</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/fchirica\" style=\"text-decoration:none;color:black !important;\">fchirica's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"10531\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/10476\"> <p>Codeforces Round #225 — Editorial</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/fchirica\" title=\"Candidate Master fchirica\" class=\"rated-user user-violet\">fchirica</a>,\r\n <span class=\"format-humantime\" title=\"Jan/20/2014 22:18\">10 years ago</span>,\r\n \r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><h1><a href=\"/contest/384/problem/A\" title=\"Codeforces Round 225 (Div. 2)\">384A - Coder</a></h1><p>Usually, when you don’t have any idea how to approach a problem, a good try is to take some small examples.</p><p>So let’s see how it looks for N = 1, 2, 3, 4 and 5. With C I noted the coder and with * I noted an empty cell.</p><p><img alt=\" \" src=\"/predownloaded/8f/89/8f899efd227362957f283123a7927c7c8a300667.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>By now you should note that answer is N ^ 2 / 2 when N is even and (N ^ 2 + 1) / 2 when N is odd. Good. Generally, after you find a possible solution by taking examples, you need to prove it, then you can code it.</p><p>In order to proof it, one needs to do following steps:</p><p>1/ prove you can always build a solution having N ^ 2 / 2 (or (N ^ 2 + 1) / 2) pieces.</p><p>2/ prove that N ^ 2 / 2 (or (N ^ 2 + 1) / 2) is maximal number – no other bigger solution can be obtained.</p><p>For proof 1/ imagine you do coloring like in a chess table.</p><p><img alt=\" \" src=\"/predownloaded/50/12/50120d92bd0cea3d6a434d09ab4754ea20342351.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>The key observation is that by placing all coders on black squares of table, no two coders will attack. Why? Because a piece placed at a black square can attack only a piece placed at a white square. Again, why? Suppose chess table is 1-based. Then, a square (i, j) is black if and only if i + j is even. A piece placed at (i, j) can attack (i + 1, j), (i – 1, j) (i, j + 1) or (i, j – 1). The sum of those cells is i + j + 1 or i + j – 1. But since i + j is even, i + j + 1 and i + j – 1 are odd, hence white cells.</p><p>Depending on parity of N, number of black cells is either N ^ 2 / 2 or (N ^ 2 + 1) / 2. For N even, one can observe that there are equal amount of black and white cells. Total number of cells is N ^ 2, so number of black cells is N ^ 2 / 2. For N odd, number of black cells is number of white cells + 1. We can imaginary add a white cell to the board. Now, number of black cells will be also equal to number of white cells, so answer is (N ^ 2 + 1) / 2.</p><p>2/ Two coders attack each other if they are placed at two adjacent cells, one black and other one white. One needs to prove that adding more than number from 1/ will cause this to happen. If you place a coder at a white cell, you won’t be able to place at least one coder at a black cell, so in best case you don’t win anything by doing this. Hence, it’s optimally to place all coders on same color cells. Since cells colored in black are always more or equal to white ones, it’s always optimally to choose black color. But number from 1/ is the number of cells having black color. Adding one more piece will force you to add it to a white color cell. Now, you’ll have a piece placed at a black colored cell and one placed at an adjacent white colored cell, so two coders will attack. Hence, we can’t place more than number from 1/ pieces.</p><p>Code: <a href=\"http://pastie.org/8651801\">http://pastie.org/8651801</a></p><h1><a href=\"/contest/384/problem/B\" title=\"Codeforces Round 225 (Div. 2)\">384B - Multitasking</a></h1><p>Let’s start by saying when array A[] is sorted:</p><p>1/ is sorted in ascending order when i < j and A[i] <= A[j]. It is NOT sorted when i < j and A[i] > A[j].</p><p>2/ is sorted in descending order when i > j and A[i] <= A[j]. It is NOT sorted when i > j and A[i] > A[j].</p><p>Iahub can choose 2 indices i, j and swap values when A[i] > A[j]. If A[i] <= A[j], he’ll ignore operation. Hence, if he wants to sort all arrays in ascending order, he chooses indices i, j when i < j and perform operation. Otherwise, in all his operations he uses indices i, j such as i > j. A “good” operation is when choosing indices i < j for ascending order sorting and i > j for descending order sorting. By doing only good operations, after an array is sorted, it will stay sorted forever (for a sorted array, all good operations will be ignored).</p><p>From here we get our first idea: use any sorting algorithm you know and sort each array individually. When print swaps done by sorting algorithm chosen, print them as good operations. However, sorting each array individually can cause exceeding M * (M — 1) / 2 operations limit. Another possible solution would be, after you did an operation to an array, to update the operation to all arrays (you printed it, so it counts to M * (M — 1) / 2 operations limit; making it to all arrays will help sometimes and in worst case it won’t change anything). However, you need to code it very careful in order to make this algorithm pass the time limit. Doing this in a contest is not the best idea, especially when implementation could be complicated and you have no guarantee it will pass time limit.</p><p>So what else can we do? We can think out of box. Instead of sorting specific N arrays, you can sort all possible arrays of length M. Find a sequence of good operations such as, anyhow I’d choose an array of size M, it will get sorted ascending / descending.</p><p>I’ll show firstly how to do for ascending sorting. At position 1 it needs to be minimal element. Can we bring minimal element there using good operations? Yes. Just do “1 2” “1 3” “1 4” ... “1 M”. It basically compares element from position 1 to any other element from array. When other element has smaller value, swap is done. After comparing with all M elements, minimal value will be at position 1. By now on I’ll ignore position 1 and move to position 2. Suppose array starts from position 2. It also needs minimal value from array, except value from position 1 (which is no longer in array). Hence doing “2 3” “2 4” “2 5” ... “2 M” is enough, by similar reasons. For a position i, I need minimal value from array, except positions 1, 2, ..., i – 1. I simply do “i i+1” “i i+2” ... “i M-1” “i M”. By arriving at position i, array will be sorted ascending. The algorithm is simply:</p><p>for (int i = 1; i < M; ++i)</p><p>for (int j = i + 1; j <= M; ++j)</p><p>cout << i << “ “ << j << “\\n”;</p><p>This algorithm does exactly M * (M — 1) / 2 moves.</p><p>Can you find out how to sort array in descending order? Try to think yourself, then if you don’t get it read next. At first position of a descending array it needs to be maximal value. Similarly to ascending order, we can do “2 1” “3 1” “4 1” ... “M 1”. When I’m at a position i and I compare its value to value from position 1, doing operation “i 1” checks if A[i] > A[1]. If so, it swaps A[i] and A[1], so position 1 will contain now the maximum value so far. Similarly to logic from ascending order, when I’m at position i, I need maximum value from array except positions 1, 2, ..., i – 1, so I do “i+1 i” “i+2 i” ... “M i”. Algorithm is:</p><p>for (int i = 1; i < M; ++i)</p><p>for (int j = i + 1; j <= M; ++j)</p><p>cout << j << “ “ << i << “\\n”;</p><p>Obviously, this does as well M * (M — 1) / 2 operations worst case. All algorithm is about 10 lines of code, much better than other solution, which requires two manually sorts and also has a chance to exceed TL.</p><p>Code: <a href=\"http://pastie.org/8651809\">http://pastie.org/8651809</a></p><h1><a href=\"/contest/384/problem/C\" title=\"Codeforces Round 225 (Div. 2)\">384C - Milking cows</a></h1><p>A good strategy to approach this problem is to think how optimal ordering should look like. For this, let’s calculate for each 2 different cows i and j if cow i needs to be milked before or after cow j. As we’ll show, having this information will be enough to build optimal ordering. It is enough to consider only cases when i < j, case when i > j is exactly the opposite of case i < j. For formality, I’ll call the optimal ordering permutation and lost milk the cost of permutation.</p><p>So, for an optimal permutation P let’s take 2 numbers i < j and see in which cases i should appear before j in permutation (i is before j if P[pos1] = i, P[pos2] = j and pos1 < pos2; otherwise we’ll call i is after j). We have 4 possible cases:</p><p>1/ A[i] = 0 and A[j] = 0</p><p>If we put i before j, no additional cost will be added. Since j is in right of i and i only adds cost when it finds elements in left of i, j won’t be affected when processing i. When processing j, i will be already deleted so it won’t affect the cost either. Hence, we can put i before j and no cost will be added.</p><p>2/ A[i] = 0 and A[j] = 1</p><p>Here, i and j can appear in arbitrary order in permutation (i can be before or after j). No matter how we choose them, they won’t affect each other and cost will remain the same.</p><p>3/ A[i] = 1 and A[j] = 0</p><p>As well, here i and j can appear in arbitrary order. If we choose i first, j will be in right of it, so cost of permutation will increase by one. If we choose j first, i will be in left of it so cost of permutation will increase as well. No matter what we do, in this case cost of permutation increases by 1.</p><p>4/ A[i] = 1 and A[j] = 1</p><p>Here, i needs to be after j. This adds 0 cost. Taking i before j will add 1 cost to permutation (since j is in right of i).</p><p>Those 4 cases show us how a minimal cost permutation should look. In a permutation like this, only case 3/ contributes to final cost, so we need to count number of indices i, j such as i < j and A[i] = 1 and A[j] = 0 (*). If we show a permutation following all rules exists, task reduces to (*).</p><p>By cases 2/ and 3/ it follows that in an optimal permutation, it only matters order of elements having same value in A[]. We can put firstly all elements having value 0 in A[], then all elements having value 1 in A[]. We can order elements having value 0 by case 1/ and elements having value 1 by case 4/. More exactly, suppose i1 < i2 < ... < im and (A[i1] = A[i2] = ... = A[im] = 0) and j1 > j2 > ... > jn (A[j1] = A[j2] = ... = A[jn] = 1). Then, a permutation following all rules is {i1, i2, ..., im, j1, j2, ..., jn}. This permutation can always be built.</p><p>Hence, task reduces to (*): count number of indices i, j such as i < j and A[i] = 1 and A[j] = 0. We can achieve easily an O(N) algorithm to do this. Let’s build an array cnt[j] = number of 0s in range {j, j + 1, ..., N} from array A. We can easily implement it by going backwards from N to 1. The result is sum of cnt[i], when A[i] = 1.</p><p>Code: <a href=\"http://pastie.org/8651813\">http://pastie.org/8651813</a></p><h1><a href=\"/contest/384/problem/D\" title=\"Codeforces Round 225 (Div. 2)\">384D - Volcanoes</a></h1><p>Our first observation is that if there is a path from (1, 1) to (N, N), then the length of path is 2 * N – 2. Since all paths have length 2 * N – 2, it follows that if there is at least one path, the answer is 2 * N – 2 and if there isn’t, the answer is -1. How to prove it? Every path from (1, 1) to (N, N) has exactly N – 1 down directions and exactly N – 1 right directions. So, total length for each path is N – 1 + N – 1 = 2 * N – 2. </p><p>So we reduced our problem to determine if there is at least one path from (1, 1) to (N, N). This is the challenging part of this task, considering that N <= 10 ^ 9. How would you do it for a decently small N, let’s say N <= 10^3 . One possible approach would be, for each row, keep a set of reachable columns. We could easily solve this one by doing this: if (i, j) denotes element from ith row and jth column, then (i, j) is (is not) reachable if:</p><p>if (i, j) contains a volcano, then (i, j) is not reachable. Otherwise, if at least one of (i – 1, j) and (i, j – 1) is reachable, then (i, j) is reachable. Otherwise, (i, j) is not reachable.</p><p>What’s the main problem of this approach? It needs to keep track of 10^9 lines and in worst case, each of those lines can have 10^9 reachable elements. So, worst case we need 10^9 * 10^9 = 10^18 operations and memory.</p><p>Can we optimize it? We can note for beginning that we don’t need to keep track of 10^9 lines, only m lines are really necessarily. We need only lines containing at least one obstacle (in worst case when each line contains only one obstacle, we need m lines). How to solve it this way? Suppose line number x contains some obstacles and lines x + 1, x + 2, x + 3 do not contain any obstacle. Suppose we calculated set S = {y | cell (x, y) is reachable}. How would look S1, S2, S3 corresponding to lines x + 1, x + 2, x + 3? For S1, we can reach cell (x + 1, ymin), where ymin is minimal value from set S. Then, we can also reach {ymin + 1, ymin + 2, ..., N}, by moving right from (x + 1, ymin). So S1 = {ymin, ymin + 1, ..., N}. How do S2 and S3 look? It’s easy to see that they’ll be as well {ymin, ymin + 1, ..., N}. So we get following optimization: suppose set of lines containing at least one obstacle is {L1, L2, ..., Lk}. We need to run algorithm only for lines L1, L1 + 1, L2, L2 + 1, L3, L3 + 1, ..., Lk, Lk + 1.</p><p>It looks like we didn’t make anything with this optimization. Even if we calculate for m lines, each line can still have 10^9 reachable positions. So worst case we perform 10^14 operations. We need something better for managing information from a line. You can note that for a given line y, there are a lot of positions having consecutive values. There are a lot of positions (x, y) and (x, y + 1) both reachable. This should give us following idea: what if instead of keeping reachable positions, we keep reachable ranges? That is, for each line x we keep a set of ranges S = {(a, b) | all cells (x, k) with a <= k <= b are reachable}. </p><p>How many ranges can it be for a line? If the line contains m obstacles, there are m + 1 ranges. Suppose for line x all cells are reachable, but for line x + 1 cells (x + 1, 3) (x + 1, 5) (x + 1, N – 1) are blocked. Then, the ranges of reachable cells are [1, 2] [4, 4], [6, N – 2] and [N, N]. By now, we get worst case m lines and worst case each line having m elements, so in worst case we’d have to handle m * m = 10 ^ 10 events. This may still look too much, but happily this bound is over estimated. If a line has o obstacles, there can be at most o + 1 ranges. If lines L1, L2, ..., Lk have {o1, o2, ..., ok} obstacles, there’ll be at most o1 + o2 + ... + ok + k ranges. But o1 + o2 + ... + ok = m and also k is at most m (proved above why we’re interested in at most m lines), so in worst case we get m + m = 2 * m ranges. Yaay, finally a decent number of states for this problem :)</p><p>So, we iterate each line we’re interested in. Let’s find set of ranges for this line, thinking that all cells from line above are reachable. This is easy to do. After we get our ranges like all cells from above can be visited, let’s think how having obstacles above can influence current ranges. After adding ranges from above, current ranges can’t increase (obviously), they can only decrease, remain the same or some of them can become empty. So, let’s take each range [a, b] from current line and see how it will transform after adding ranges from previous line. </p><p>Given range [a, b], it can transform only in [a’ , b] with a’ >= a. If a’ > b, then obviously range is empty. Why second number of range keeps constant? Let a’ smallest reachable column from current line which is in range [a, b]. It’s enough to check a’ >= a, as if a’ > b, range will be empty. It’s obviously why we need to keep a’ smallest value possible >= a: we’re interested to keep range as big as possible and as less as we cut from left, as big it is. Once we’ve found a’ in range [a, b] (or a’ > b if range is empty) all cells {a’ + 1, a’ + 2, ..., b} are reachable as well by going right from a’, so if interval is not empty, then second number defining it remains b.</p><p>Next question is how to find a’ fast enough. In order a point a’ to be reachable on current range, it also needs to exist a range on previous line containing it. If the range from previous line is [pa, pb] then a’ needs to follow 3 conditions:</p><p>a’ minimal such as</p><p>pa <= a’ <= pb</p><p>a’ >= a</p><p>What if instead of finding a’ we find [pa, pb]? Then a’ is max(pa, a). In order a’ to be as small as possible, since a is constant, pa needs to be as small as possible. So we reduced it to:</p><p>pa minimal pb >= a’ >= a <=> pb >= a</p><p>Intervals from previous line are disjoint, no 2 intervals cross each other. It means that if pb is minimal, than pa is minimal too (if we increase pb, then pa will increase too, so it won’t be minimal). Hence, you need to find an interval [pa, pb] such as pb is minimal and pb >= a. Then, a’ is max(a, pa). This is easy to do if we sort all intervals from previous line increasing by second value (pb), then we binary search for value a. </p><p>Finally, after running algorithm for all lines, last range from last line has second number N (assuming ranges are sorted increasing by second value), then there exist a path, otherwise there does not exist. This algorithm should run O(m * logm) worst case, good enough to pass. </p><p>Code: <a href=\"http://pastie.org/8651817\">http://pastie.org/8651817</a></p><h1><a href=\"/contest/384/problem/E\" title=\"Codeforces Round 225 (Div. 2)\">384E - Propagating tree</a></h1><p>This is kind of task that needs to be break into smaller subproblems that you can solve independently, then put them together and get solution.</p><p>Let’s define level of a node the number of edges in the path from root to the node. Root (node 1) is at level 0, sons of root are at level 1, sons of sons of root are at level 2 and so on.</p><p>Now suppose you want to do an operation of type 1 to a node x. What nodes from subtree of x will be added +val (a positive value)? Obviously, x will be first, being located at level L. Sons of x, located at level L + 1 will be added –val. Sons of sons, located at level L + 2, will be added value +val again. So, nodes from subtree of x located at levels L, L + 2, L + 4, ... will be added a +val, and nodes located at levels L + 1, L + 3, L + 5 will be added a –val. Let’s take those values of L modulo 2. All nodes having remainder L modulo 2 will be added a +val, and nodes having reminder (L + 1) modulo 2 will be added –val. In other words, for a fixed x, at a level L, let y a node from subtree of x, at level L2. If L and L2 have same parity, +val will be added to y. Otherwise, -val will be added to y.</p><p>From here we have the idea to split nodes of tree in 2 sets – those being located at even level and those being located at odd level. What still makes the problem hard to solve? The fact that we have a tree. If nodes from a subtree would be a contiguous sequence instead of some nodes from a tree, problem would be simpler: the problem would reduce to add / subtract values to all elements of a subarray and query about a current value of an element of array. So, how can we transform tree to an array, such as for a node x, all nodes from subtree of x to be a subarray of array?</p><p>The answer is yes. We can do this by properties of DFS search. Before reading on, make sure that you know what is discovery time and finish time in a DFS search. Let’s build 3 arrays now – discover[], representing nodes in order of their discover times (a node is as before in discover as it has a small discover time), begin[] = for a node, in which time it was discovered and end[] = what’s last time of a discovered node before this node finishes. For a subtree of x, all nodes in the subtree are nodes in discover from position begin[x] to end[x].</p><p>Example: suppose you have tree 1-5; 1-6; 6-7; 6-4; 4-2; 4-3</p><p>Discover is {1, 5, 6, 7, 4, 2, 3}.</p><p>begin is {1, 6, 7, 5, 2, 3, 4}.</p><p>end is {7, 6, 7, 7, 2, 7, 4}.</p><p>What’s subtree of node 6? elements of discover from position begin[6] to end[6]. In this case, from 3 to 7, so elements {6, 7, 4, 2, 3}. You can see it’s correct and take more examples if you want :)</p><p>Now, we reduced problem to: you’re given an array A. you can perform 2 operations:</p><p>1/ increase all elements from a range [x, y] to a value val (val can be negative, to treat subtractions)</p><p>2/ what’s current value of an element from position pos.</p><p>Those who solved “Iahub and Xors” from my last round, CF 198, should probably say they saw something similar before. If you didn’t solve problem before, I encourage you to do it after you solve this one, it uses a similar idea to what will follow now. Also, if you don’t know Fenwick trees, please read them before moving on. An alternative would be for this task using segment trees with lazy update, but I see this one more complicated than needed.</p><p>I’ll use now a not so common approach when dealing with data structures. Instead of keeping in a node the result, like you usually do, I’ll keep just an auxiliary information. So what algorithm proposed does:</p><p>Let A an array, initially with all elements 0.</p><p>When you need to update range [x, y] with value val, you simply do A[x] += val and A[y + 1] -= val.</p><p>When you need to answer a query about position pos, you output A[1] + A[2] + ... + A[pos].</p><p>Implemented brute force, you get O(1) per update and O(N) per query. However, these both are operations supported by a Fenwick tree, so you can get O(logN) per operation.</p><p>It may not be very clear why this algorithm works. Let’s take a closer look: an update needs to add value val only to range [x, y]. When you query a position pos, let’s see if algorithm handles it correctly:</p><p>1/ pos < x. In this case, result must not be affected by my update. Since pos < x and I only updated 2 values with indices >= x, when doing A[1] + A[2] + ... + A[pos] it won’t matter at all I did that update – at least not for this query.</p><p>2/ x <= pos <= y. Here, for a pos, I need to add value val only once. We add it only at A[x] – in this way it will be counted once, and it will be considered for each elements from range [x, y] (since an element at position p from range [x, y] has p >= x, in A[1] + A[2] + ... + A[p] I’ll have to consider A[x]).</p><p>3/ pos > y. Here I don’t have to consider the query. But it would be considered when processing A[x]. But if I add to A[y + 1] value –val I’ll just cancel the value previously added.</p><p>Code (actually we use just one Fenwick tree instead of 2, can you think why it works? :) ) : <a href=\"http://pastie.org/8651824\">http://pastie.org/8651824</a></p><h1><a href=\"/contest/383/problem/D\" title=\"Codeforces Round 225 (Div. 1)\">383D - Antimatter</a></h1><h2>Author's solution</h2><p>The problem is: given an array, iterate all possible subarrays (all possible elements such as their indexes are consecutive). Now, for a fixed subarray we need to know in how many ways we can color its elements in black and white, such as sum of black elements is equal to sum of white elements. The result is sum of this number, for each subarray.</p><p>Let’s solve an easier problem first. This won’t immediately solve the harder version, but it will be useful later. Suppose you’ve fixed a subarray. In how many ways can you color it with black and white? Suppose subarray has N elements and sum of them is M. Also, suppose for a coloring, sum of blacks is sB and sum of whites is sW. For coloring to be valid, sB = sW. But we also know that sB + sW = M (because each element is colored by exactly one color). We get that 2 * sB = M, so sB = M / 2. The problem is now: in how many ways can we color elements in black such as sum of blacks is M / 2 (after we fix a black coloring, we color with white non colored elements; sum of white colored elements is also M / 2). This is a well known problem: Knapsack problem. Let ways[i][j] = in how many ways one can obtain sum j from first i elements. When adding (i + 1) object, after ways[i] is calculated, for a fixed sum j we can do 2 things: add (i + 1) object to sum j or skip it. Depending of what we chosen, we add value ways[i][j] to ways[i + 1][j + value[i + 1]] or to ways[i + 1][j]. The result is in ways[N][M / 2]. This works in O(N * M) time.</p><p>An immediate solution can be obtained now: take all subarrays and apply above approach. This leads to an O(N ^ 2 * M ^ 2) solution, which is too much. One can reduce complexity to O(N ^ 2* M) by noting that processing subarray [i, j] can be done with already calculated values for subarray [i, j – 1]. Hence, instead of adding N elements, it’s enough to add 1 element to already calculated values (element from position j). Sadly, O(N ^ 2 * M) is still too slow, so we need to find something better. The solution presented below will look forced if you didn’t solve some problems with this technique before. It’s hard to come with an approach without practicing this kind of tasks. But don’t worry, as much as you practice them, as easily you’ll solve those problems.</p><p>We’ll solve task by divide and conquer. Complexity of this solution is O(N * M * logN). Let f(left, right) a function that counts number of colorings for each subarray [i, j], such as subarray [i, j] is included in subarray [left, right] (left <= i <= j <= right). Answer is in f(1, N). The trick is to define a value med = (left + right) / 2 (very frequent trick in divide and conquer problems, called usually a median). We can next classify [i, j] subarrays in 3 types:</p><p>1/ i <= med j <= med</p><p>2/ i > med j > med</p><p>3/ i <= med j > med</p><p>We can solve 1/ and 2/ by calling f(left, med) and f(med + 1, right). The remained problem is when i <= med and j > med. If we solve 3/ in O((right – left) * M) time, this will be enough to overall achieve O(N * M * logN) (for this moment trust me, you’ll see later why it’s so :) ).</p><p>Let’s denote by i1 last i1 elements from subarray [left, med]. Also, let’s note by i2 first i2 elements from subarray [med + 1, right]. For example, let left = 1 and right = 5, with array {1, 2, 3, 4, 5}. med is 3 and for i1 = 2 and i2 = 1, “left” subarray is {2, 3} and “right” subarray is {4}. By iterating i1 from 1 to med – left + 1 and i2 from 1 to right – med and then unite subarrays i1 and i2, we obtain all subarrays described in 3/ . Let’s denote by j1 sum of a possible black coloring of i1. Similarly, j2 is sum of a possible black coloring of i2.</p><p>Suppose we fixed i1, i2, j1 and j2. When it’s the coloring valid? Let S sum of united subarrays i1 and i2 (S = value[med – i1 + 1] + value[med – i1 + 2] + ... + value[med] + value[med + 1] + ... + value[med + i2 – 1] + value[med + i2]). Now it’s time to use what I explained at the beginning of solution. The coloring is good only when j1 + j2 = S / 2. We can rewrite the relation as 2 * (j1 + j2) = sum_of_elements_from_i1 + sum_of_elements_from_i2. We can rewrite it even more:</p><p>2 * j1 + 2 * j2 — sum_of_elements_from_i1 — sum_of_elements_from_i2 = 0</p><p>2 * j1 – sum_of_elements_from_i1 = sum_of_elements_from_i2 – 2 * j2 = combination_value</p><p>This relation is the key of solving problem. You can see now that relation is independent in “left” and “right” side. We calculate left[i1][j1] and right[i2][j2] = in how many ways can I obtain sum of blacks j1 (j2) from first i1 (i2) from left (right) side. Let’s calculate also count[value] = in how many ways can I obtain combination_value equal to value in the right side. For some fixed (i2, j2) I add to count[sum_of_elements_from_i2 – 2 * j2] value right[i2][j2]. In this way count[] is calculated correctly and completely. Now, let’s fix a sum (i1, j1) in the left side. We’re interested how many good colorings are such as there exist a coloring of j1 in i1 elements (the endpoint of “left” is fixed to be i1 and I need to calculate endpoints i2 for right, then to make colorings of i2). A coloring is good if combination_value of (i1, j1) and (i2, j2) is equal. Hence, I need to know in how many ways I can color i1 elements to obtain sum j1 and also I need to know in how many ways I can color elements from right to obtain same combination_value as it’s in the left. It’s not hard to see that answer for a fixed (i1, j1) is left[i1][j1] * count[2 * j1 – sum_of_elements_from_i1]. This takes O((right – left) * M) time.</p><p>The only thing remained in the problem is to see why complexity is O(N * M * logN). We can assume N is a power of 2 (it not, let’s round N to smallest power of 2 bigger than N; complexity for N is at least as good as complexity for this number). Draw a binary complete tree with N nodes. Each node corresponds to an appeal of f(). For a level, exactly O(N * M) operations are performed. To see why:</p><p>For level 1, there’ll be 1 node performing N * M operations.</p><p>For level 2, there’ll be 2 nodes performing (N / 2) * M operations. Summing up we get O(N * M).</p><p>For level 3, there’ll be 4 nodes performing (N / 4) * M operations. Summing up we get O(N *M) as well.</p><p>and so on.</p><p>So for each level we perform O(N * M) operations. A binary complete tree has maximum O(logN) levels, so overall complexity is O(N * M * logN).</p><p>Code: <a href=\"http://pastie.org/8651826\">http://pastie.org/8651826</a></p><h2>Solution fount by contestants</h2><p>This was totally unexpected to us :) Good job finding it, you guys are really smart. </p><p>We observe that x units of antimatter is the same thing as -x units of matter. Then we can consider that an element produces either x or -x units of matter. A valid substring is one that can have the sum of the elements 0. The problem is reduced to finding how many different substrings can we have with sum 0 (a substring is different than another one if it has different indices, or if at least one element produces matter in one and antimatter in the other).</p><p>This problem can be solved with dynamic programming. We will hold D[i][j] = the number of substrings that end in element i, and have sum j. It's easy to see that D[i + 1][j] = D[i][j — x] + D[i][j + x], where x is the value of the current element (we can put either -x or x). After we finish computing all the values for current i, we add to the solution D[i][0] (how many valid substrings do we have). After that, we add 1 to D[i][0], meaning that there is an empty substring starting at position i (however, we don't need to add it to the answer).</p><p>For a code, check passing submissions during contest. </p><h2><a href=\"/contest/383/problem/E\" title=\"Codeforces Round 225 (Div. 1)\">383E - Vowels</a></h2><h2>Author's solution</h2><p>Let's iterate over all possible vowel sets. For a given set {x1, x2, ..., xk} we're interested in number of correct words from dictionary. After a precalculation, we can do it in O(k).</p><p>Suppose our current vowel set is {x1, x2, ..., xk}. How many words are covered by the current vowels? By definition, we say a word is covered by a set of vowels if at least one of 3 letters of word is in vowel set. We can calculate this number using principle of inclusion and exclusion. We’ll denote by |v1, v2, v3, ...| = number of words containing ALL of vowels v1, v2, v3, ... . Using principle of inclusion and exclusion we get:</p><p>number_of_words_covered = |x1| + |x2| + .. + |xk| — |x1, x2| — |x1, x3| — .... + |x1, x2, x3| + |x1, x2, x4| + .... + |xk-2, xk-1, xk|. This formula is simply a reformulation of principle of inclusion and exclusion. You can easily observe that |v1, v2, ..., vk| makes sense only when k is at most 3, as no word from input can contain 4 or more letters (and hence can’t contain 4 or more vowels). </p><p>Example:</p><p>Suppose words are abc, abd and bcd. </p><p>|a| = 2 (first 2 words both contain character a).</p><p>|a, b| = 2 (as well, first 2 words contain characters a and b).</p><p>|b| = 3 (all 3 words contain character b).</p><p>|a, b, d| = 1 (only second word contains all 3 characters).</p><p>Also, note how principle of inclusion and exclusion works. number of words covered for vowels {a, b} is |a| + |b| — |a, b| = 2 + 3 – 2. Indeed, answer is 3.</p><p>We divide our problem in 3 subproblems. First one, for a vowel set, compute sum of |a|, where a is a letter from subset. Second, compute sum of |a, b|, where both a and b are letters from set. Third, compute sum of |a, b, c|, where a, b, c are letters from set. As stated, the answer is number_from_1st_step + number_from_3rd_step – number_from_2nd_step. If you followed me, you’ll see that we want to compute results for each subproblem in O(queryLetters).</p><p>First subproblem can be solved trivially in O(queryLetters). Let array single[], with following meaning: single[c] is how many words contain character c. It can be trivially precomputed in O(24 * N). Note that if a word contains twice/third times a character c, it needs to be counted only one (e.g. word aba will add only 1 to single[a]). For compute result of this subproblem for a given set of vowels, I’ll take all letters from set. If letter belongs to set, I add to result single[letter]. This step can be also be solved in O(1), but there’s no need, since other subproblems allow only an O(queryLetters) solution. </p><p>For second and third subproblems it’s a little more difficult. I’ll present here how to solve second subproblem and some hints for third one (if you understand second, with hints you should be able to solve third one by your own).</p><p>Similarly to first step, I’ll define a matrix double[c1][c2] = how many words contain both characters c1 and c2. A trivially solution would be, for a given vowel set, take all combinations of letters c1 and c2 that belong to set and add to result value double[c1][c2]. However, this solves each query in O(queryLetters^2), which is too slow.</p><p>Note, if we’d have 12 letters, instead of 24, this approach would be fast enough. From here it comes a pretty classical idea in exponential optimization: meet in the middle attack. We split those 24 letters in 2 groups: first 12 letters and last 12 letters. The answer for a subset is sum of double[c1][c2] (when c1 and c2 belong to current vowel set) when</p><p>1/ c1 and c2 belong to first 12 letters</p><p>2/ c1 and c2 belong to last 12 letters</p><p>3/ c1 belongs to first 12 letters and c2 belongs to last 12 letters</p><p>1/ and 2/ can be immediately precalculated as stated above, in O(2 ^ 12 * 12 ^ 2). We’ll remember results for each half using bitmasks arrays. Let Half1[mask] = sum over double[c1][c2], when c1 and c2 are in first 12 letters and correspond to 1 bits of mask. Half2[mask] is defined similarly, but for last 12 letters (e.g. subset {a, c, d} corresponds to bitmask 2^0 + 2^2 + 2^3 = 13 in first half and subset {m, n, p} corresponds to bitmask 2^0 + 2^1 + 2^3 = 11 for second half). Now, for a given subset, one can answer first 2 parts in O(queryCount) worst case (read input for a query and convert it to bitmasks). </p><p>How to answer 3? With another precalculation, of course. We know c1 letter needs to be in first 12 letters and c2 needs to be in last 12 letters. The precalculation we do here is: mixed_half[mask][i] = sum over |c1, c2|, when c1 belongs to first half and is a 1 bit of mask and c2 is i-th character of second half. Hence, for a query, we can fix character from second half (c2, by iteration of query letters from second half) and know sums of |c1, c2| between it and all available characters from first half after we do this precalculation. Also, precalculation is done trivially in O(2 ^ 12 * 12^2): fix mask, fix i and then iterate over 1 bits from mask and add double[c1][c2]. </p><p>Third subproblem is left, but it can be done similarly to second one. Instead of double[c1][c2], we’ll have triple[c1][c2][c3] = how many words contain all 3 characters c1, c2 and c3? We also do meet in the middle here, divide those 24 letters into 2 sets of 12 letters. We have 4 cases:</p><p>1/ c1, c2, c3 belong to first half</p><p>2/ c1, c2, c3 belong to second half</p><p>3/ c1, c2 belong to first half and c3 to second half</p><p>4/ c1 belongs to first half and c2, c3 to second half</p><p>1/ and 2/ are done brute force, like in second subproblem (the only difference is we choose 3 characters instead of 2, having complexity O(2 ^ 12 * 12 ^ 3)). For 3/ and 4/ we also precompute 2 matrixes: </p><p>mixed_two_one[mask][i] = c1 and c2 belong to mask from first half and c3 is i-th character from second half </p><p>and </p><p>mixed_one_two[mask][i] = c1 is i-th character from first half and c2, c3 belong to mask from second half. </p><p>Those can also be calculated in O(2 ^ 12 * 12^3).</p><p>So precalculation part is O(2 ^ 12 * 12 ^ 3) = 7077888 operations.</p><p>For calculate answering queries complexity, take all numbers from 0 to 2^24 — 1 and sum their bit count. This is a well known problem, the sum is 0 * C(24, 0) + 1 * C(24, 1) + ... + 24 * C(24, 24) = 201326592. In total we get 208404480 operations. C++ source makes them in 2 seconds. </p><p>Code: <a href=\"http://pastie.org/8651829\">http://pastie.org/8651829</a></p><h2>Solution fount by contestants</h2><p>Like in D1 D task, official solution was over complicated. This solution is more simple to understand, code and it's more elegant. If someone wants to complicate his life, (s)he can code also official solution :)</p><p>Let's start by assigning a bitmask to each word in following way: ith bit is 1 if and only if letter ('a' + i) appears in the current word. For example, for word acd, its bitmask is 2^0 + 2^2 + 2 ^ 3 = 13 and for word aab its bitmask is 2^0 + 2^1 = 3. After reading the words from dictionary, we store a matrix cnt[mask] = how many words from dictionary correspond to mask?</p><p>We iterate bitmasks from 0 to 2^24 — 1, this time corresponding to each possible question of Iahubina. Let's focus on a bitmask X. We need to get sum of cnt[mask], when mask and X share at least one common bit having value 1 (formally (X AND mask) > 0). In order to do this, we need a reduction which may be not so obvious. </p><p>What if instead of counting all words containing at least one of vowels {w1, w2, ..., wk} we count all words which don't contain ANY of vowels {w1, w2, ..., wk}? Suppose this number is ret. Then, all words containing at least one of vowels is N — ret. From all words, we erase those words which do not contain any vowels from set {w1, w2, ..., wk} (and which obviously are wrong words). Obviously, it's left only words containing at least one vowel, so good words. Now, for a word not to contain any of vowels {w1, w2, ..., wk} it needs to contains ONLY vowels from set {"a", "b", "c", ..., "x"} \\ {w1, w2, ..., wk} (set of allowed letters from which we erased vowels w1, w2, ..., wk}. </p><p>And this is reduction we needed. For a bitmask X we need to calculate sum of cnt[mask], where mask is a subset of X (we can set some bits from X from 1 to 0 in order to obtain mask). For a mask, let's keep this sum in res[mask]. We can calculate res array using divide and conquer.</p><p>Let's make a function solve(left, right), which completes array res in the way described above, if we consider only elements cnt[k] with left <= k < right (for simplicity, I'll consider elements which do not lie in this range to be equal to 0). Now we need to solve for a range [left, right]. Let's have in res1[] = solve(left, med) and in res2[] = solve(med, right), where med = (left + right) / 2. We need to put together res1[] and res2[] in order to obtain res[].</p><p>for (int i = left; i < med; ++i) res[i] = res1[i];</p><p>Numbers in [left, med] have most significant bit equal to 0. We can only keep it 0 and add what we calculated before. We can't add any element from res2[], because those elements have most significant bit equal to 1 and we're not allowed to change bit 0 into bit 1.</p><p>for (int i = med; i < right; ++i) res[i] = res1[i — med] + res2[i];</p><p>Here, most significant bit is 1. Adding res1[] corresponds to changing bit from 1 to 0, adding res2[] corresponds to leaving bit 1.</p><p>Of course, we need to threat the base case here, too. When left + 1 = right, res[left] = cnt[left]. We can keep only one array res[] instead of 3, I explained it this way only for simplicity. Also, there is no need for keeping separate arrays for res[] and cnt[], one can solve all task with only one array. In order to get res[], we simply call solve(0, 2^24).</p><p>Complexity of solution is O(2 ^ 24 * 24). I leave the proof homework, it's almost identical to complexity proof of D1 D "Author solution" (that with building a binary tree).</p><p>For a reference solution, check <a class=\"rated-user user-red\" href=\"/profile/Endagorion\" title=\"Grandmaster Endagorion\">Endagorion</a>'s AC source during contest. </p></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/384\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 225 (Div. 2)</a> </span>\r\n </div>\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/383\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 225 (Div. 1)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-12457-10531\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"12457\",\n blogEntryId: \"10476\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n <div style=\"font-size: 1.1rem;line-height: 11px;\">\r\n <img style=\"vertical-align: middle;\" src=\"//codeforces.org/s/81027/images/blog/tags.png\" title=\"Tags\" alt=\"Tags\"/>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=codeforces\" class=\"tag notice\" style=\"text-decoration: none;\">codeforces</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=225\" class=\"tag notice\" style=\"text-decoration: none;\">225</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=editorial\" class=\"tag notice\" style=\"text-decoration: none;\">editorial</a>\r\n </span>\r\n </div>\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-10531\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+418</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-10531\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/fchirica\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/fchirica\">\n fchirica\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Jan/20/2014 22:18\">10 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/10476#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/10476#comments\">\n 52\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"10547\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (45)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158582\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PAP\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/78534/avatar/d5bcc04085999f83.jpg'/> </a>\n <div><a href=\"/profile/PAP\" title=\"Candidate Master PAP\" class=\"rated-user user-violet\">PAP</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 22:40\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158582\" href=\"?#comment-158582\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158582\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"32\"\r\n data-commentUserId=\"78534\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+32</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158582\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>perfect editorial! thanks a lot!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158582 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158582 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158582\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158591\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/eduardische\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2320/avatar/3ac70493aa90ad2e.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/eduardische\" title=\"International Master eduardische\" class=\"rated-user user-orange\">eduardische</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 22:48\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158591\" href=\"?#comment-158591\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"158591\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"158591\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"10\"\r\n data-commentUserId=\"2320\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+10</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158591\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Just would like to report a typo in 383D contestants' solution: the formula computes D[i+1][j] and not D[i][j]. Thanks for the quick editorial!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158591 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158591 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158591\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158596\" commentParentId=\"158591\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/fchirica\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/57267/avatar/4e655c69b8ad66c2.jpg'/> </a>\n <div><a href=\"/profile/fchirica\" title=\"Candidate Master fchirica\" class=\"rated-user user-violet\">fchirica</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 22:52\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158596\" href=\"?#comment-158596\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-158591\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158596\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"15\"\r\n data-commentUserId=\"57267\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+15</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158596\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks. Fixed. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158596 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158596 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158596\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158598\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Mikester\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/109566/avatar/401b6d72d8f2e768.jpg'/> </a>\n <div><a href=\"/profile/Mikester\" title=\"Master Mikester\" class=\"rated-user user-orange\">Mikester</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 22:54\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158598\" href=\"?#comment-158598\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158598\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"13\"\r\n data-commentUserId=\"109566\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+13</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158598\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>elfus has some of the best rounds on Codeforces, and definitely the best editorials. Congratulations to you and Rares for the round !</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158598 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158598 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158598\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158599\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/iPs\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/144469/avatar/10358ae72910ceac.jpg'/> </a>\n <div><a href=\"/profile/iPs\" title=\"Expert iPs\" class=\"rated-user user-blue\">iPs</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 22:54\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158599\" href=\"?#comment-158599\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158599\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"33\"\r\n data-commentUserId=\"144469\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+33</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158599\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>best editorial I have ever seen in codeforces</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158599 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158599 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158599\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158600\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/bli0042\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/88584/avatar/51c3a9b55a3537fa.jpg'/> </a>\n <div><a href=\"/profile/bli0042\" title=\"Candidate Master bli0042\" class=\"rated-user user-violet\">bli0042</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 22:54\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158600\" href=\"?#comment-158600\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"158600\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"158600\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"88584\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158600\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For Div 2C, if A[i] = A[j] = 0 and we put i before j, won't j lose milk? Or am I misinterpreting the solution?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158600 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158600 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158600\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158601\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/aabs08\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/aabs08\" title=\"Expert aabs08\" class=\"rated-user user-blue\">aabs08</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 22:55\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158601\" href=\"?#comment-158601\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"158601\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"158601\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"9\"\r\n data-commentUserId=\"86699\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+9</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158601\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>One of the best editorials i came across in codeforces :D otherwise the editorial here are really very short and objective.</p><p>Every one here should write editorials like you :) !!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158601 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158601 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158601\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158607\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Xellos\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/69675/avatar/8526bcfc8e687b43.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/Xellos\" title=\"International Grandmaster Xellos\" class=\"rated-user user-red\">Xellos</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 23:03\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158607\" href=\"?#comment-158607\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"158607\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"158607\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"17\"\r\n data-commentUserId=\"69675\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+17</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158607\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Finally a tutorial worth upvoting!</p><p>I didn't really need to think about D. As soon as I saw the constraint on <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/986936bec272878d92f9c6fb0f0ce3c5b118cc0e.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />, I decided to try a DP on (position,sum) — it was a massive hint for me. Well, sometimes it just happens that there's a simple solution, which the author doesn't realize :D. Maybe this could be eliminated by some extensive "problem testing" by random capable people?</p><p>I guess I was also lucky in not trying to solve B. I solved in the order: A (because it's easy), C (because I like it), D (because it's easy) :D</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158607 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158607 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158607\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158610\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Mostafa_36a2\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/137637/avatar/28a01293a2b409.jpg'/> </a>\n <div><a href=\"/profile/Mostafa_36a2\" title=\"Specialist Mostafa_36a2\" class=\"rated-user user-cyan\">Mostafa_36a2</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 23:09\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158610\" href=\"?#comment-158610\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158610\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"-9\"\r\n data-commentUserId=\"137637\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-9</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158610\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I've found a very short solution for Div2 C , by zxz5759209</p> <pre><code>scanf("%d",&n);\n LL cnt=0,sum=0;\n for(int i=1;i<=n;i++)\n {\n scanf("%d",&x);\n cnt+=(LL)x;\n if(!x)sum+=cnt;\n }\n printf("%I64d\\n",sum);\n</code></pre></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158610 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158610 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158610\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158641\" commentParentId=\"158610\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Robert.One\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Robert.One\" title=\"Pupil Robert.One\" class=\"rated-user user-green\">Robert.One</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 01:27\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158641\" href=\"?#comment-158641\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-158610\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158641\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"150202\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158641\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I also had this solution and i got accepted but it took 1 hour to find it during the contest</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158641 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158641 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158641\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158612\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Darek_\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Darek_\" title=\"Specialist Darek_\" class=\"rated-user user-cyan\">Darek_</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 23:12\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158612\" href=\"?#comment-158612\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158612\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"152123\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158612\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks for an informative editorial.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158612 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158612 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158612\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158618\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Mostafa_36a2\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/137637/avatar/28a01293a2b409.jpg'/> </a>\n <div><a href=\"/profile/Mostafa_36a2\" title=\"Specialist Mostafa_36a2\" class=\"rated-user user-cyan\">Mostafa_36a2</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 23:25\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158618\" href=\"?#comment-158618\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"158618\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"158618\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"137637\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158618\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Unbelivable solution for Div2,B by Sick_Coder</p> <pre><code>cin >> n >> m >> k;\n cout << m * (m - 1) / 2 << "\\n";\n\n for (1, m, i)\n \tfor (i + 1, m, j)\n \t\tif (!k)\n \t\t\tcout << i << " " << j << "\\n";\n \t\telse\t\n \t\t\tcout << j << " " << i << "\\n";\n</code></pre></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158618 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158618 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158618\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158631\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mugurelionut\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/63702/avatar/45e4d5390c215090.jpg'/> </a>\n <div><a href=\"/profile/mugurelionut\" title=\"International Master mugurelionut\" class=\"rated-user user-orange\">mugurelionut</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 23:57\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158631\" href=\"?#comment-158631\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158631\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"63702\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158631\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>A very good editorial, indeed! (but please don't forget about Div1E) And the problems were really nice. But I think problem B was tougher than it should have been for its amount of points. I've read some comments saying that problem B had too weak pretests (because so many solutions failed the final system tests). I would have to say that my experience with problem B was the exact opposite. I coded two wrong solutions (which failed some pretest or another) before eventually finding and implementing the right solution. So I'd say that problem B had good pretests :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158631 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158631 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158631\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158635\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/MohammadFatafta\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/148405/avatar/4276577919b9713d.jpg'/> </a>\n <div><a href=\"/profile/MohammadFatafta\" title=\"Specialist MohammadFatafta\" class=\"rated-user user-cyan\">MohammadFatafta</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 00:11\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158635\" href=\"?#comment-158635\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158635\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"148405\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158635\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>now this is a real editorial!! thanks guys :D</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158635 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158635 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158635\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158636\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/matrix\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/matrix\" title=\"Master matrix\" class=\"rated-user user-orange\">matrix</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 00:15\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158636\" href=\"?#comment-158636\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"158636\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"158636\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"16572\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158636\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Hi,</p><p>Great and fast editorial with complete details. </p><p>Thanks very much.</p><p>Edit: I think there is a small typo: "It’s not hard to see that answer for a fixed (i1, j1) is left[i1][j1] * value[2 * j1 – sum_of_elements_from_i1]." I guess you meant count[2 * j1 – sum_of_elements_from_i1].</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158636 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158636 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158636\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158637\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Kyuubi\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/83590/avatar/b87432a652bb276.jpg'/> </a>\n <div><a href=\"/profile/Kyuubi\" title=\"Expert Kyuubi\" class=\"rated-user user-blue\">Kyuubi</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 00:18\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158637\" href=\"?#comment-158637\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158637\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"2\"\r\n data-commentUserId=\"83590\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+2</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158637\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Best Editorials I have seen on codeforces yet! :D</p><p>For Propagating tree, how do we keep track of alternating levels in the arrays we created using DFS ? </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158637 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158637 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158637\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158640\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/k_____k\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/60285/avatar/422359e1ae9d666c.jpg'/> </a>\n <div><a href=\"/profile/k_____k\" title=\"Expert k_____k\" class=\"rated-user user-blue\">k_____k</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 01:07\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158640\" href=\"?#comment-158640\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158640\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"2\"\r\n data-commentUserId=\"60285\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+2</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158640\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Best Editorials Ever ! #thanks to the authors, for posting alternative solutions of contestants also. Great start in 2014. #Looking Forward.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158640 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158640 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158640\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158658\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/sillycross\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/41652/avatar/58966d0c793c6394.jpg'/> </a>\n <div><a href=\"/profile/sillycross\" title=\"Grandmaster sillycross\" class=\"rated-user user-red\">sillycross</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 07:49\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158658\" href=\"?#comment-158658\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158658\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"9\"\r\n data-commentUserId=\"41652\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+9</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158658\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Div1 E can be solved in O(2^24*24) or O(2^24+2^12*n)..</p><p>O(2^24*24): dp[i][s] means the sum of all contributions of subset s where all digits are same as s except the last i digits.. </p><p>O(2^24+2^12*n): the length of word is only 3. We divide the 24 letters in half, calculate the answer for all first 12 letters and all last 12 letters and merge them with brute-force. This can be solved in O(2^24). Then we subtract the words that are counted twice: these words are words that have 2 letters in first half and 1 in second half, or 2 in second half and 1 in first half. Let's consider the first case: for each subset of first 12 letters we check each word whether it has exactly 2 letters in this half, if so, we can say all masks in another half that contains the third letter need to be subtracted by 1. This can be solved in 2^12*(2^12+n). Same algorithm can be used to solve the second case. Although this algorithm runs slower than O(2^24*24) bcuz of its larger constant... </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158658 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158658 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158658\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158663\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/VeniVidiVici\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/VeniVidiVici\" title=\"Candidate Master VeniVidiVici\" class=\"rated-user user-violet\">VeniVidiVici</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 09:39\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158663\" href=\"?#comment-158663\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158663\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"149163\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158663\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Very nice editorial! Disappointed in Div 2B though, really expected the "real" problem rather than just insertion sort but that's what you get for not reading carefully ;)</p><p>However, does anyone have an accepted solution that is "real" (e.g. finds the minimum number of operations necessary and prints such a solution)? I was close but my computer died during contest and I haven't tried so much since (of course you can do O((mn)^2) easily but this is way too slow, there should be a O(n*m^2) solution but again my computer was unable to operate). My approach was to make 2-D boolean array to check if a swap is necessary, but I'm not sure if order of operations will end up being a big problem.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158663 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158663 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158663\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158685\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/LegendaryGrandmaster\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/142091/avatar/a3a5a4b5c26ac419.jpg'/> </a>\n <div><a href=\"/profile/LegendaryGrandmaster\" title=\"Specialist LegendaryGrandmaster\" class=\"rated-user user-cyan\">LegendaryGrandmaster</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 14:34\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158685\" href=\"?#comment-158685\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158685\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"142091\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158685\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>One of the best codeforces editorials ever! Thanks!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158685 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158685 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158685\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158687\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/BENYAM1N\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/84938/avatar/d2ae2657d8898e38.jpg'/> </a>\n <div><a href=\"/profile/BENYAM1N\" title=\"Master BENYAM1N\" class=\"rated-user user-orange\">BENYAM1N</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 15:24\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158687\" href=\"?#comment-158687\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"158687\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"158687\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"84938\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158687\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks a lot. very good contest and good editorial too!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158687 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158687 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158687\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158689\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/JuanMata\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/82548/avatar/a7d69af7b441c6d7.jpg'/> </a>\n <div><a href=\"/profile/JuanMata\" title=\"Expert JuanMata\" class=\"rated-user user-blue\">JuanMata</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 15:47\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158689\" href=\"?#comment-158689\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158689\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"82548\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158689\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>this is one of the best editorials on CF ever!!!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158689 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158689 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158689\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158700\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Vicfred\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/76941/avatar/d067b7433ec39337.jpg'/> </a>\n <div><a href=\"/profile/Vicfred\" title=\"Pupil Vicfred\" class=\"rated-user user-green\">Vicfred</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 16:25\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158700\" href=\"?#comment-158700\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158700\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"11\"\r\n data-commentUserId=\"76941\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+11</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158700\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>The best editorial I've read in a while here, thanks.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158700 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158700 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158700\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158727\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/beecoder\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/beecoder\" title=\"Pupil beecoder\" class=\"rated-user user-green\">beecoder</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 21:13\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158727\" href=\"?#comment-158727\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158727\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"89551\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158727\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Hi, The way I print answers for 'Coder Problem' is as follows. This takes 124 ms. is there a way to print the answers faster ? </p> <pre><code> \tfor (int i = 0 ; i < number ; i ++ ) { \n \t\tfor (int k = 0 ; k < number ; k ++ ) { \n \t\t\tif (flag) {\n \t\t\t\tif ( k % 2 == 1) out.print('.');\n \t\t\t\tif( k% 2 == 0 ) out.print('C');\n \t\t\t} else {\n \t\t\tif ( k % 2 == 1) out.print('C');\n \t\t\tif( k% 2 == 0 ) out.print('.');\t\n \t\t\t}\n \t\t}\n \t\tif (flag) flag = false;\n \t\telse flag = true;\n \t\tout.print("\\n");\n \t}\n \n</code></pre></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158727 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158727 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158727\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158742\" commentParentId=\"158727\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Mostafa_36a2\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/137637/avatar/28a01293a2b409.jpg'/> </a>\n <div><a href=\"/profile/Mostafa_36a2\" title=\"Specialist Mostafa_36a2\" class=\"rated-user user-cyan\">Mostafa_36a2</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/22/2014 14:00\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158742\" href=\"?#comment-158742\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-158727\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158742\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"137637\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158742\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>As the line contains k characters , and every odd lines are identical , also the even ones,</p><p>you can build 2 strings [C.C.C.C] and [.C.C.C.] and print them alternately </p><p>[In my opinion Java is slow language any way ]</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158742 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158742 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158742\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158752\" commentParentId=\"158727\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/t_thirupathi\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/146179/avatar/98c28348196ce4ca.jpg'/> </a>\n <div><a href=\"/profile/t_thirupathi\" title=\"Specialist t_thirupathi\" class=\"rated-user user-cyan\">t_thirupathi</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/22/2014 18:19\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158752\" href=\"?#comment-158752\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-158727\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158752\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"146179\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158752\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Modulo operations are time consuming.</p><p>To check if a number <code>n</code> is odd, you could use <code>if (n & 1)</code></p> <pre><code>for (int i = 0; i < n; i++) {\n for (int j = 0; j < n; j++)\n if ((i + j) & 1)\n out.print('.');\n else \n out.print('C');\n out.print('\\n');\n}\n</code></pre></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158752 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158752 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158752\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158745\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/JuanMata\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/82548/avatar/a7d69af7b441c6d7.jpg'/> </a>\n <div><a href=\"/profile/JuanMata\" title=\"Expert JuanMata\" class=\"rated-user user-blue\">JuanMata</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/22/2014 14:49\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158745\" href=\"?#comment-158745\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"158745\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"158745\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"82548\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158745\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>i think there is a small bug in the <a href=\"http://pastie.org/8651824\">pastie link</a> u posted for the solution of Div1 C problem.</p><p>i submitted almost exact copy of it (<a href=\"/contest/383/submission/5769615\" title=\"Submission 5769615 by JuanMata\">5769615</a>), but got WA#6. then i found the bug, corrected it and resubmitted (<a href=\"/contest/383/submission/5769890\" title=\"Submission 5769890 by JuanMata\">5769890</a>) and got AC.</p><p>referring to my two submissions, corrections in line <strong>68</strong> (last statement of <strong>dfs</strong>) and line <strong>109</strong> (the second call to <strong>update</strong>).</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158745 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158745 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158745\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"615836\" commentParentId=\"158745\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/adityakr007\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/adityakr007\" title=\"Expert adityakr007\" class=\"rated-user user-blue\">adityakr007</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/05/2020 18:54\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-615836\" href=\"?#comment-615836\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-158745\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"615836\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"866209\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-615836\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can you explain what exactly have you done in your submission (<a href=\"/contest/383/submission/5769890\" title=\"Submission 5769890 by JuanMata\">5769890</a>) for this problem?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-615836 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-615836 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-615836\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"629531\" commentParentId=\"615836\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/JuanMata\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/82548/avatar/a7d69af7b441c6d7.jpg'/> </a>\n <div><a href=\"/profile/JuanMata\" title=\"Expert JuanMata\" class=\"rated-user user-blue\">JuanMata</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/25/2020 18:14\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-629531\" href=\"?#comment-629531\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-615836\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"629531\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"82548\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-629531\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>sorry bro i've forgotten ... that was over 6yrs ago now!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-629531 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-629531 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-629531\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158751\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/TempuX\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/30820/avatar/c50adc243ea4e2fa.jpg'/> </a>\n <div><a href=\"/profile/TempuX\" title=\"Specialist TempuX\" class=\"rated-user user-cyan\">TempuX</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/22/2014 17:07\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158751\" href=\"?#comment-158751\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158751\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"30820\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158751\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Hi, I tried to implement the Volcano problem in the way explained in the editorial but I'm getting TLE. Here is my code <a href=\"//codeforces.com/contest/384/submission/5770818\">submission</a> What am I doing wrong ? Thanks anyway.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158751 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158751 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158751\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158811\" commentParentId=\"158751\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/TempuX\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/30820/avatar/c50adc243ea4e2fa.jpg'/> </a>\n <div><a href=\"/profile/TempuX\" title=\"Specialist TempuX\" class=\"rated-user user-cyan\">TempuX</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/23/2014 17:29\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158811\" href=\"?#comment-158811\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-158751\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158811\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"30820\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158811\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Turns out my binary search is causing the problem and I don't see what is wrong with it... I would appreciate any ideas.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158811 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158811 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158811\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159025\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/bboy_drain\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/76710/avatar/e0feb3aa135911d4.jpg'/> </a>\n <div><a href=\"/profile/bboy_drain\" title=\"Expert bboy_drain\" class=\"rated-user user-blue\">bboy_drain</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/25/2014 01:34\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159025\" href=\"?#comment-159025\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159025\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"76710\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159025\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Wow! This really helped me a lot! Very detailed explanations!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159025 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159025 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159025\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159092\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/AlexandruValeanu\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/131651/avatar/1c7d989c45052941.jpg'/> </a>\n <div><a href=\"/profile/AlexandruValeanu\" title=\"Candidate Master AlexandruValeanu\" class=\"rated-user user-violet\">AlexandruValeanu</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/25/2014 21:27\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159092\" href=\"?#comment-159092\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159092\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"131651\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159092\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>It was by far your best round on Codeforces, <a class=\"rated-user user-blue\" href=\"/profile/fchirica\" title=\"Expert fchirica\">fchirica</a>. The problems were great, very different one from the other and some of them didn't require any algorithmic skills at all. Good job!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159092 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159092 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159092\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159261\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lawsonh\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/lawsonh\" title=\"Expert lawsonh\" class=\"rated-user user-blue\">lawsonh</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/28/2014 06:33\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159261\" href=\"?#comment-159261\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"159261\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"159261\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"55047\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159261\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>for div1 383C should end[5] = 7? edit: nvm drew the tree wrong</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159261 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159261 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159261\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159474\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/tiagonapoli\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/150060/avatar/6615fcab66b23361.jpg'/> </a>\n <div><a href=\"/profile/tiagonapoli\" title=\"Candidate Master tiagonapoli\" class=\"rated-user user-violet\">tiagonapoli</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/30/2014 22:28\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159474\" href=\"?#comment-159474\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159474\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"150060\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159474\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Great Editorial! Thanks so much, i've learned a lot!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159474 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159474 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159474\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159707\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lchf\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/60496/avatar/e9939e755252ec16.jpg'/> </a>\n <div><a href=\"/profile/lchf\" title=\"Candidate Master lchf\" class=\"rated-user user-violet\">lchf</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/02/2014 17:28\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159707\" href=\"?#comment-159707\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159707\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"60496\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159707\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Amazing solution by Endagorion.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159707 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159707 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159707\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"177400\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/sourabh912\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/57335/avatar/bf83b9340e3cbb17.jpg'/> </a>\n <div><a href=\"/profile/sourabh912\" title=\"Specialist sourabh912\" class=\"rated-user user-cyan\">sourabh912</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/12/2014 20:39\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-177400\" href=\"?#comment-177400\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"177400\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"57335\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-177400\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In Div 1C problem, I could not understand how it can be solved using single fenwick tree from the solution link in the editorial. Can anyone please help.</p><p>Thanks</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-177400 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-177400 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-177400\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"291157\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/l_Love_KFC\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/258117/avatar/bbaec3ce1613f5bd.jpg'/> </a>\n <div><a href=\"/profile/l_Love_KFC\" title=\"Expert l_Love_KFC\" class=\"rated-user user-blue\">l_Love_KFC</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Apr/29/2016 08:23\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-291157\" href=\"?#comment-291157\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"291157\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"258117\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-291157\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In Div.1 A I didn't catch the point that in 1st, quote : "If we put i before j, no additional cost will be added. Since j is in right of i and i only adds cost when it finds elements in left of i, j won’t be affected when processing i." Won't we lose milk if we put firstly i, in case of that j sees that and loses milk? Or am I misunderstanding the task? </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-291157 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-291157 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-291157\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"309434\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/haleyk100198\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/416324/avatar/f2d97d505af17e9d.jpg'/> </a>\n <div><a href=\"/profile/haleyk100198\" title=\"Candidate Master haleyk100198\" class=\"rated-user user-violet\">haleyk100198</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/11/2016 06:32\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-309434\" href=\"?#comment-309434\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"309434\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"416324\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-309434\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I wonder how the problem Div1C can be converted to a segment tree lazy propagation implementation question, for trees like (1-2 2-3 3-4 4-5 .... 9999-E4) how can we achieve O(log N) update time?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-309434 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-309434 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-309434\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"310847\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/my_new_handle\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/233736/avatar/24128c61b65e3262.jpg'/> </a>\n <div><a href=\"/profile/my_new_handle\" title=\"Candidate Master my_new_handle\" class=\"rated-user user-violet\">my_new_handle</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/20/2016 14:49\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-310847\" href=\"?#comment-310847\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"310847\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"233736\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-310847\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>а зачем в таске б массив он влияет как-то?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-310847 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-310847 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-310847\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"332763\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/rhezo\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/305605/avatar/aa59e9c2ec688c6a.jpg'/> </a>\n <div><a href=\"/profile/rhezo\" title=\"Candidate Master rhezo\" class=\"rated-user user-violet\">rhezo</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Dec/24/2016 07:56\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-332763\" href=\"?#comment-332763\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"332763\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"305605\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-332763\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I'm getting Runtime Error on test 44 in <a href=\"//codeforces.com/problemset/problem/383/C\">Propogating Tree</a>. </p><p>This is because of stack overflow right? That test has N = 2e5 and for a straight chain of nodes, I'll get a runtime error with a recursive DFS right? What to do in such cases? </p><p>I can write an iterative DFS, but I do HLD recursively too and I'm not quite sure if I can write an iterative HLD. </p><p>Can anyone tell me what to do in such cases? I'm assuming that I got the runtime error due to stackoverflow from DFS.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-332763 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-332763 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-332763\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"346070\" commentParentId=\"332763\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/yinanzhu\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/520731/avatar/d61a58bf5df54146.jpg'/> </a>\n <div><a href=\"/profile/yinanzhu\" title=\"Expert yinanzhu\" class=\"rated-user user-blue\">yinanzhu</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/26/2017 07:18\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-346070\" href=\"?#comment-346070\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-332763\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"346070\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"520731\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-346070\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I used recursive dfs and passed all test case. Test 44 cost 1.5 s</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-346070 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-346070 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-346070\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"387028\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/blue__legend\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/blue__legend\" title=\"Expert blue__legend\" class=\"rated-user user-blue\">blue__legend</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/23/2017 07:16\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-387028\" href=\"?#comment-387028\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"387028\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"284949\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-387028\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>How to solve DIV 1 C using one fenwick or segment tree. The code link given in editorial is not working.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-387028 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-387028 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-387028\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"757423\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Ausmosian\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Ausmosian\" title=\"Expert Ausmosian\" class=\"rated-user user-blue\">Ausmosian</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/05/2021 15:05\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-757423\" href=\"?#comment-757423\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"757423\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"727283\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-757423\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>[<a href=\"https://codeforces.com/contest/383/problem/C\">384E — Propagating tree</a>] Can also be solved using Square Root Decomposition. <a href=\"https://codeforces.com/contest/383/submission/106526543\">Submission</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-757423 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-757423 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-757423\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"838255\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/3hill\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1621900/avatar/478297db63bad207.jpg'/> </a>\n <div><a href=\"/profile/3hill\" title=\"Expert 3hill\" class=\"rated-user user-blue\">3hill</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/11/2021 17:02\">2 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-838255\" href=\"?#comment-838255\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"838255\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1621900\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-838255\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I am Getting MLE on TC-53<br />Can someone review my code and figure out the issue ,Thanks</p> <ul> <li><a href=\"https://codeforces.com/contest/383/problem/C\">Problem</a></li> <li><a href=\"https://codeforces.com/contest/383/submission/128510633\">My code</a></li> </ul></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-838255 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-838255 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-838255\">\r\n </ul>\r\n</div>\r\n <br/>\r\n\r\n<div id=\"editBox-10547\" style=\"width:50em;display:none;\">\r\n <div class=\"previewBody\" style=\"border: 1px solid #d4d4d4; margin-bottom: 0.5em; padding: 0.25em; display:none;\"> </div>\r\n <div style=\"width: 1px\"> </div>\r\n <div class=\"commentLocale\" style=\"position: relative; top: 0.5em;left:4px;display: none;\">\r\n <input type=\"radio\" name=\"locale\" value=\"en\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In English</span>\r\n <input style=\"margin-left:1em\" type=\"radio\" name=\"locale\" value=\"ru\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In Russian</span>\r\n </div>\r\n <textarea data-drafts-id=\"CommentReplyFrame\" class=\"wysiwyg\" name=\"editContent\" rows=\"20\" style=\"width:99%;\"></textarea>\r\n <div class=\"error error__content\"></div>\r\n <div style=\"text-align:center;\">\r\n <input type=\"button\" name=\"preview\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Preview\"/>\r\n <input type=\"button\" name=\"save\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Save\"/>\r\n </div>\r\n</div>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n\r\nvar firstPreview10547 = true;\r\nvar lastPreviewContent10547 = '';\r\n\r\nif (!window.moveCommentRevision) {\r\n moveCommentRevision = function(e, dir) {\r\n var p = e.parent();\r\n var revisionCount = parseInt(p.attr(\"revisionCount\"));\r\n var revision = parseInt(p.attr(\"revision\"));\r\n var next = revision + dir;\r\n var commentId = p.attr(\"commentId\");\r\n if (next >= 1 && next <= revisionCount) {\r\n $.post(\r\n \"/data/comment-data\",\r\n {action: \"revision\", commentId: commentId, revision: next},\r\n function(json) {\r\n if (json.success == \"true\") {\r\n var parentDiv = e;\r\n\r\n while (parentDiv !== null && (parentDiv[0].nodeName.toLowerCase() !== \"td\" || !parentDiv.hasClass(\"right\"))) {\r\n parentDiv = parentDiv.parent();\r\n }\r\n\r\n if (parentDiv === null) {\r\n return;\r\n }\r\n\r\n parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\").html(json.content);\r\n Codeforces.setupSpoilers(parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\"));\r\n p.attr(\"revision\", next);\r\n p.find(\"span.revision\").text(next);\r\n if (next == 1) {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"visible\");\r\n }\r\n if (next == revisionCount) {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"visible\");\r\n }\r\n\r\n window.updateTypography();\r\n MathJax.Hub.Typeset();\r\n } else {\r\n alert(e.error);\r\n }\r\n },\r\n \"json\"\r\n );\r\n }\r\n };\r\n}\r\n\r\n$(\"div[commentableId=10547] a.leftRevision\").click(function () {\r\n window.moveCommentRevision($(this), -1);\r\n return false;\r\n});\r\n\r\n$(\"div[commentableId=10547] a.rightRevision\").click(function () {\r\n window.moveCommentRevision($(this), +1);\r\n return false;\r\n});\r\n\r\n\r\n\r\n });\n </script>\n\r\n\r\n <script src=\"//codeforces.org/s/81027/js/swfobject-2.2.min.js\" type=\"text/javascript\"></script>\n <script src=\"//codeforces.org/s/81027/js/ftaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n if (window.evercookie) {\n var ec = new evercookie({\n history: false,\n silverlight: false,\n baseurl: '',\n asseturi: '/assets',\n phpuri: '/2fdcd78',\n pngPath: '/eps',\n etagPath: '/ees',\n cachePath: '/ecs'\n });\n\n var randomNumber = function () {\n return Math.random().toString(36).substr(2);\n };\n\n var randomToken = function () {\n return (randomNumber() + randomNumber()).substring(0, 18);\n };\n\n window._ftaa = \"\";\n\n ec.get(\"70a7c28f3de\", function (value) {\n window._ftaa = value;\n if (!window._ftaa) {\n window._ftaa = randomToken();\n ec.set(\"70a7c28f3de\", window._ftaa);\n }\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n } else {\n window._ftaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\n <script src=\"//codeforces.org/s/81027/js/bfaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n var fpCallback = function() {\n Fingerprint2.get({}, function(components) {\n window._bfaa = Fingerprint2.x64hash128(components.map(function (pair) { return pair.value }).join(), 31);\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n };\n if (typeof Fingerprint2 !== 'undefined') {\n if (window.requestIdleCallback) {\n requestIdleCallback(fpCallback)\n } else {\n setTimeout(fpCallback, 500)\n }\n } else {\n window._bfaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"a.new-root-comment\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n\r\n $(\".comment-table .reply a\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".vote-for-comment\").mouseover(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").mouseout(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").click(function () {\r\n var vote = $(this);\r\n var commentId = $(this).parent().attr(\"commentid\");\r\n var commentRating = $(this).parent().attr(\"data-commentRating\");\r\n var direction = $(this).attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n $.post(\"/data/comment/vote\", {commentId: commentId, _tta: Codeforces.tta(), vote: direction, commentRating: commentRating}, function(data) {\r\n if (direction != 0 && !ownComment && data[\"success\"] == \"true\") {\r\n vote.parent().find(\".vote-for-comment\").attr(\"voteDirection\", 0);\r\n if (direction == 1)\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n else {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.closest(\".CommentVoteFrame\").find(\".ComplaintFrame\").css(\"display\", \"inline-block\");\r\n }\r\n vote.find(\"img\").attr(\"popacity\", \"1.0\");\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n vote.parent().find(\".commentRating\").html(data[\"commentRating\"]);\r\n }\r\n Codeforces.showMessage(data[\"message\"]);\r\n }, \"json\");\r\n return false;\r\n });\r\n\r\n $(\".negative-comment-vote\").closest(\".comment-table\").addClass(\"comment-bad\");\r\n\r\n $(\".troll-comment-vote\").closest(\".comment\").css(\"display\", \"none\");\r\n\r\n $(\".too-negative-comment-vote\").closest(\".comment-table\").each(function () {\r\n var e = $(this);\r\n e.addClass(\"comment-too-bad\");\r\n var commentId = e.attr(\"commentId\");\r\n $(\"<div class='bad-comment-replacement ttypography'>The comment is hidden because of too negative feedback, click <a href=# class=show-bad-comment-link>here</a> to view it</div>\").appendTo(\r\n e.find(\".right\")\r\n );\r\n e.find(\".comment-content\").hide();\r\n e.find(\".show-bad-comment-link\").click(function () {\r\n e.find(\".comment-content\").show();\r\n e.find(\".bad-comment-replacement\").hide();\r\n return false;\r\n });\r\n });\r\n });\n </script>\n </div>\r\n\r\n <style type=\"text/css\">\r\n .new-comments-box {\r\n padding: 0.5em;\r\n width: 22px;\r\n font-size: 1.3rem;\r\n font-weight: bold !important;\r\n\r\n position: fixed;\r\n top: 40%;\r\n right: 0;\r\n opacity: 0.2;\r\n color: white;\r\n text-align: center;\r\n\r\n border: 1px solid #222;\r\n background-color: #888 !important;\r\n border-radius: 3px;\r\n -moz-border-radius: 3px;\r\n -webkit-border-radius: 3px;\r\n }\r\n\r\n .new-comments-box:hover {\r\n opacity: 1;\r\n }\r\n\r\n .new-comments-box .dir:hover {\r\n background: #3B5998 !important;\r\n cursor: pointer;\r\n }\r\n </style>\r\n\r\n <div class=\"new-comments-box\" data-position=\"outside\" data-index=\"-1\" style=\"display: none;\">\r\n <div class=\"up dir\" title=\"Ctrl+Up\">↑<hr/>\r\n </div>\r\n <div class=\"info\" title=\"New comments\"></div>\r\n <div class=\"down dir\" title=\"Ctrl+Down\">\r\n <hr/>↓\r\n </div>\r\n </div>\r\n\r\n <script>\r\n $(\".show-archived-checkbox\").change(function () {\r\n const checked = $(this).is(\":checked\");\r\n $.post(\"/data/comment-data\", {action: \"setShowArchived\", checked}, function (json) {\r\n if (json[\"success\"] !== \"true\") {\r\n alert(json[\"error\"]);\r\n } else {\r\n if (checked) {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are now displayed\")\r\n } else {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are no longer displayed\")\r\n }\r\n }\r\n });\r\n return false;\r\n });\r\n\r\n function gotoComment(direction) {\r\n var box = $(\".new-comments-box\");\r\n var index = parseInt(box.attr(\"data-index\"));\r\n if (index == -1)\r\n index = 0;\r\n else\r\n index = Math.max(0, Math.min(parseInt(box.find(\".info\").text()) - 1, index + direction));\r\n box.attr(\"data-index\", index);\r\n var comment = $($(\".comment .highlight-blue[commentId]\").get(index));\r\n $('html, body').animate({\r\n 'scrollTop': Math.max(0, comment.offset().top - ($(window).height() - comment.height()) / 2)\r\n });\r\n return false;\r\n }\r\n\r\n $(\".new-comments-box .down\").click(function () {\r\n return gotoComment(1);\r\n });\r\n\r\n $(\".new-comments-box .up\").click(function () {\r\n return gotoComment(-1);\r\n });\r\n\r\n $(document).keydown(function (e) {\r\n var code = (e.keyCode ? e.keyCode : e.which);\r\n if (e.ctrlKey) {\r\n if (code == 38 || code == 40) {\r\n gotoComment(code - 39);\r\n }\r\n }\r\n });\r\n\r\n var newCommentCount = $(\".comment .highlight-blue[commentId]\").length;\r\n if (newCommentCount > 0) {\r\n $(\".new-comments-box .info\").text(newCommentCount);\r\n $(\".new-comments-box\").show();\r\n }\r\n\r\n $('table.comment-table').mouseenter(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").addClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n\r\n $('table.comment-table').mouseleave(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").removeClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n </script>\r\n\r\n\r\n\r\n <script>\r\n function adjustTopicComplainFrames() {\r\n let topicIds = [];\r\n\r\n $(\".has-topic-id\").each(function () {\r\n const $this = $(this);\r\n const topicId = $this.attr(\"topicId\");\r\n if (topicId) {\r\n topicIds.push(topicId);\r\n }\r\n });\r\n\r\n $.post(\"/data/topics\", {\r\n action: \"findComplainableTopicIds\",\r\n topicIds: topicIds.join(\",\")\r\n }, function (json) {\r\n if (json[\"success\"] === \"true\") {\r\n for (const topicId of json[\"complainableTopicIds\"].split(\",\")) {\r\n $(\".has-topic-id[topicId=\" + topicId + \"]\").each(function () {\r\n $(this).find(\".meta .ComplaintFrame\").css(\"display\", \"inline-block\");\r\n });\r\n }\r\n }\r\n }, \"json\");\r\n }\r\n\r\n $(function () {\r\n adjustTopicComplainFrames();\r\n })\r\n </script>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-10531\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 10531, _tta: Codeforces.tta(), topicRevisionId: 36233, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-10531\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 10531, _tta: Codeforces.tta(), topicRevisionId: 36233, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n </div>\r\n </div>\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 22:13:02</span> (h1).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/81027/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/81027/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/81027/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/81027/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-81027.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'81287584a8369d92',t:'MTY5NjcwNTk4Mi42NDcwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"}}},{"rowIdx":1935,"cells":{"problem_id":{"kind":"string","value":"383B"},"contest":{"kind":"string","value":"383"},"problem":{"kind":"string","value":"B"},"lang":{"kind":"string","value":"en"},"problem_title":{"kind":"string","value":"B. Volcanoes"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">B. Volcanoes</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Iahub got lost in a very big desert. The desert can be represented as a <span class=\"tex-span\"><i>n</i> × <i>n</i></span> square matrix, where each cell is a zone of the desert. The cell <span class=\"tex-span\">(<i>i</i>, <i>j</i>)</span> represents the cell at row <span class=\"tex-span\"><i>i</i></span> and column <span class=\"tex-span\"><i>j</i></span> <span class=\"tex-span\">(1 ≤ <i>i</i>, <i>j</i> ≤ <i>n</i>)</span>. Iahub can go from one cell <span class=\"tex-span\">(<i>i</i>, <i>j</i>)</span> only down or right, that is to cells <span class=\"tex-span\">(<i>i</i> + 1, <i>j</i>)</span> or <span class=\"tex-span\">(<i>i</i>, <i>j</i> + 1)</span>. </p><p>Also, there are <span class=\"tex-span\"><i>m</i></span> cells that are occupied by volcanoes, which Iahub cannot enter. </p><p>Iahub is initially at cell <span class=\"tex-span\">(1, 1)</span> and he needs to travel to cell <span class=\"tex-span\">(<i>n</i>, <i>n</i>)</span>. Knowing that Iahub needs <span class=\"tex-span\">1</span> second to travel from one cell to another, find the minimum time in which he can arrive in cell <span class=\"tex-span\">(<i>n</i>, <i>n</i>)</span>.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains two integers <span class=\"tex-span\"><i>n</i></span> <span class=\"tex-span\">(1 ≤ <i>n</i> ≤ 10<sup class=\"upper-index\">9</sup>)</span> and <span class=\"tex-span\"><i>m</i></span> <span class=\"tex-span\">(1 ≤ <i>m</i> ≤ 10<sup class=\"upper-index\">5</sup>)</span>. Each of the next <span class=\"tex-span\"><i>m</i></span> lines contains a pair of integers, <span class=\"tex-span\"><i>x</i></span> and <span class=\"tex-span\"><i>y</i></span> <span class=\"tex-span\">(1 ≤ <i>x</i>, <i>y</i> ≤ <i>n</i>)</span>, representing the coordinates of the volcanoes.</p><p>Consider matrix rows are numbered from 1 to <span class=\"tex-span\"><i>n</i></span> from top to bottom, and matrix columns are numbered from 1 to <span class=\"tex-span\"><i>n</i></span> from left to right. There is no volcano in cell <span class=\"tex-span\">(1, 1)</span>. No two volcanoes occupy the same location. </p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print one integer, the minimum time in which Iahub can arrive at cell <span class=\"tex-span\">(<i>n</i>, <i>n</i>)</span>. If no solution exists (there is no path to the final cell), print -1.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>4 2<br/>1 3<br/>1 4<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>6<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>7 8<br/>1 6<br/>2 6<br/>3 5<br/>3 6<br/>4 3<br/>5 1<br/>5 2<br/>5 3<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>12<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>2 2<br/>1 2<br/>2 1<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>-1<br/></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>Consider the first sample. A possible road is: <span class=\"tex-span\">(1, 1)</span> <span class=\"tex-span\"> → </span> <span class=\"tex-span\">(1, 2)</span> <span class=\"tex-span\"> → </span> <span class=\"tex-span\">(2, 2)</span> <span class=\"tex-span\"> → </span> <span class=\"tex-span\">(2, 3)</span> <span class=\"tex-span\"> → </span> <span class=\"tex-span\">(3, 3)</span> <span class=\"tex-span\"> → </span> <span class=\"tex-span\">(3, 4)</span> <span class=\"tex-span\"> → </span> <span class=\"tex-span\">(4, 4)</span>.</p></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"b7dc0983bf4f59b073b52dd819064a6e\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - B - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"f2f8284d26a4a4d6b4f15082f9e1ab3f212e9edd\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - B - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/73366/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/73366/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/73366/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/73366/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/73366/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/73366/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/73366/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/73366/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/73366/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/73366/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/73366/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/73366/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/73366/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/73366/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/sidebar-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/a037fe51637846d9c7c725713cd840ea/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='b7dc0983bf4f59b073b52dd819064a6e'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/73366/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/73366/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fcontest%2F383%2Fproblem%2FB%3Flocale%3Den\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"current\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='b7dc0983bf4f59b073b52dd819064a6e'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:100%;\"><a style=\"color: black\" href=\"/contest/383\">Codeforces Round 225 (Div. 1)</a></th>\n </tr>\n <tr>\n <td class=\"left bottom\" colspan=\"1\"><span class=\"contest-state-phase\">Finished</span></td>\n </tr>\n </tbody>\n </table>\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Practice?\n <div class=\"top-links\">\n </div>\n </div>\n<div>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Want to solve the contest problems after the official contest ends? Just register for practice and you will be able to submit solutions.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"\" method=\"post\"><input type='hidden' name='csrf_token' value='b7dc0983bf4f59b073b52dd819064a6e'/>\r\n <input type=\"hidden\" name=\"action\" value=\"registerForPractice\"/>\r\n <input type=\"submit\" name=\"submit\" value=\"Register for practice\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div> \r\n</div>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox ContestVirtualFrame borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Virtual participation <i class=\"sidebar-caption-icon las la-angle-down\"></i>\r\n\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\" \"\r\n\r\n data-page-url=\"/data/sidebarFrames\"\r\n\r\n>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests.\n\nIf you've seen these problems, a virtual contest is not for you - solve these problems in the archive.\n\nIf you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.\n\nNever use someone else's code, read the tutorials or communicate with other person during a virtual contest.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"/contest/383/virtual\" method=\"get\">\r\n <input type=\"submit\" name=\"submit\" value=\"Start virtual contest\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div>\r\n</div>\r\n <script>\r\n $(function () {\r\n $(\".ContestVirtualFrame .sidebar-caption-icon\").click(function() {\r\n $(this).toggleClass(\"la-angle-down la-angle-right\");\r\n const $target = $(this).parent().next();\r\n $target.toggle();\r\n const dataPageUrl = $target.attr(\"data-page-url\");\r\n const collapsed = $(this).hasClass(\"la-angle-right\");\r\n const params = {\r\n action: \"setCollapsed\",\r\n sidebarFrameSimpleClassName: \"ContestVirtualFrame\",\r\n collapsed\r\n };\r\n $.each($target[0].attributes, function(i, a) {\r\n const name = a.name;\r\n if (name.startsWith(\"data-extra-key-\")) {\r\n const key = a.value;\r\n const keyIndex = parseInt(name.substring(\"data-extra-key-\".length));\r\n const value = $target.attr(\"data-extra-value-\" + keyIndex);\r\n params[key] = value;\r\n }\r\n });\r\n $.post(dataPageUrl, params, function (result) {\r\n if (result[\"success\"] !== \"true\") {\r\n Codeforces.showMessage(\"Failed to save collapsed state.\");\r\n }\r\n }, \"json\");\r\n return false;\r\n });\r\n })\r\n </script>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Problem tags\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Binary search\">\r\n binary search\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Implementation problems, programming technics, simulation\">\r\n implementation\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Sortings, orderings\">\r\n sortings\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Two pointers\">\r\n two pointers\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Difficulty\">\r\n *2500\r\n</span>\r\n </div>\n <div style=\"clear:both;text-align:right;font-size:1.1rem;\">\r\n <span title=\"Please login into the Codeforces\" class=\"notice\">No tag edit access</span>\r\n </div>\r\n</div>\r\n </div>\n\r\n<form id=\"addTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='b7dc0983bf4f59b073b52dd819064a6e'/>\r\n <input name=\"action\" type=\"hidden\" value=\"addTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"5723\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<form id=\"removeTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='b7dc0983bf4f59b073b52dd819064a6e'/>\r\n <input name=\"action\" type=\"hidden\" value=\"removeTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"5723\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<script type=\"text/javascript\">\r\n $(\".tag-box img\").click(function () {\r\n var tagName = $(this).attr(\"value\");\r\n Codeforces.confirm(\"Are you sure you want to remove this tag?\", function () {\r\n $(\"#removeTagForm input[name=tagName]\").val(tagName);\r\n $(\"#removeTagForm\").submit();\r\n }, function () {\r\n }, \"Yes\", \"No\");\r\n });\r\n\r\n $(\"#addTagLink\").click(function () {\r\n $(this).hide();\r\n $(\"#addTagLabel\").show();\r\n return false;\r\n });\r\n\r\n $(\"#addTagSelect\").change(function () {\r\n var tagName = $(this).val();\r\n if (tagName === \"\") {\r\n $(\"#addTagLabel\").hide();\r\n $(\"#addTagLink\").show();\r\n } else {\r\n $(\"#addTagForm input[name=tagName]\").val(tagName);\r\n $(\"#addTagForm\").submit();\r\n }\r\n });\r\n</script>\r\n\r\n<style type=\"text/css\">\r\n#new-resource-form tr td {\r\npadding-top: 0.5em;\r\n}\r\n#new-resource-form input:not([type=\"submit\"]) {\r\nfont-size: 0.8em;\r\n}\r\n#new-resource-form select {\r\nfont-size: 0.8em;\r\n}\r\n.new-resource-error {\r\nfont-size: 0.8em;\r\n}\r\n.resource-locale {\r\ncolor: #666;\r\nfont-family: Consolas, \"Andale Mono WT\", \"Andale Mono\", \"Lucida Console\", \"Lucida Sans Typewriter\", \"DejaVu Sans Mono\", \"Bitstream Vera Sans Mono\", \"Liberation Mono\", \"Nimbus Mono L\", Monaco, \"Courier New\", Courier, monospace;\r\n}\r\n</style>\r\n<div class=\"roundbox sidebox sidebar-menu borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Contest materials\n<div class=\"top-links\">\n</div>\n</div>\n<ul>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/10448\" title=\"Codeforces Round #225\" target=\"_blank\">Codeforces Round #225</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"2166:2167\" resourceName=\"Announcement\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n<li>\r\n<span>\r\n<a href=\"https://codeforces.com/blog/entry/10476\" title=\"Tutorial\" target=\"_blank\">Tutorial <span class=\"resource-locale\">(en)</span></a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"2170\" resourceName=\"Tutorial\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n</ul>\r\n</div></div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li class=\"current selectedLava\"><a\r\n href=\"/contest/383\">Problems</a></li>\r\n <li><a\r\n href=\"/contest/383/submit\">Submit Code</a></li>\r\n <li><a\r\n href=\"/contest/383/my\">My Submissions</a></li>\r\n <li><a\r\n href=\"/contest/383/status\">Status</a></li>\r\n <li><a\r\n href=\"/contest/383/hacks\">Hacks</a></li>\r\n <li><a\r\n href=\"/contest/383/room/1\">Room</a></li>\r\n <li><a\r\n href=\"/contest/383/standings\">Standings</a></li>\r\n <li><a\r\n href=\"/contest/383/customtest\">Custom Invocation</a></li>\r\n</ul>\r\n</div>\n\r\n <style>\r\n #facebox .content:has(.diff-popup) {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n }\r\n\r\n .testCaseMarker {\r\n position: absolute;\r\n font-weight: bold;\r\n font-size: 1rem;\r\n }\r\n\r\n .diff-popup {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n display: none;\r\n overflow: auto;\r\n }\r\n\r\n .input-output-copier {\r\n font-size: 1.2rem;\r\n float: right;\r\n color: #888 !important;\r\n cursor: pointer;\r\n border: 1px solid rgb(185, 185, 185);\r\n padding: 3px;\r\n margin: 1px;\r\n line-height: 1.1rem;\r\n text-transform: none;\r\n }\r\n\r\n .input-output-copier:hover {\r\n background-color: #def;\r\n }\r\n\r\n .test-explanation textarea {\r\n width: 100%;\r\n height: 1.5em;\r\n }\r\n\r\n .pending-submission-message {\r\n color: darkorange !important;\r\n }\r\n </style>\r\n <script>\r\n const OPENING_SPACE = String.fromCharCode(1001);\r\n const CLOSING_SPACE = String.fromCharCode(1002);\r\n\r\n const nodeToText = function (node, pre) {\r\n let result = [];\r\n\r\n if (node.tagName === \"SCRIPT\" || node.tagName === \"math\"\r\n || (node.classList && node.classList.contains(\"input-output-copier\")))\r\n return [];\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(OPENING_SPACE);\r\n }\r\n\r\n if (node.nodeType === Node.TEXT_NODE) {\r\n let s = node.textContent;\r\n if (!pre) {\r\n s = s.replace(/\\s+/g, \" \");\r\n }\r\n if (s.length > 0) {\r\n result.push(s);\r\n }\r\n }\r\n\r\n if (pre && node.tagName === \"BR\") {\r\n result.push(\"\\n\");\r\n }\r\n\r\n node.childNodes.forEach(function (child) {\r\n result.push(nodeToText(child, node.tagName === \"PRE\").join(\"\"));\r\n });\r\n\r\n if (node.tagName === \"DIV\"\r\n || node.tagName === \"P\"\r\n || node.tagName === \"PRE\"\r\n || node.tagName === \"UL\"\r\n || node.tagName === \"LI\"\r\n ) {\r\n result.push(\"\\n\");\r\n }\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(CLOSING_SPACE);\r\n }\r\n\r\n return result;\r\n }\r\n\r\n const isSpecial = function (c) {\r\n return c === ',' || c === '.' || c === ';' || c === ')' || c === ' ';\r\n }\r\n\r\n const convertStatementToText = function(statmentNode) {\r\n const text = nodeToText(statmentNode, false).join(\"\").replace(/ +/g, \" \").replace(/\\n\\n+/g, \"\\n\\n\");\r\n let result = [];\r\n for (let i = 0; i < text.length; i++) {\r\n const c = text.charAt(i);\r\n if (c === OPENING_SPACE) {\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"B\" data-uuid=\"ps_25065ad0a25f0aa73073cb1ca75465e949b981ac\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">B. Volcanoes</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Iahub got lost in a very big desert. The desert can be represented as a <span class=\"tex-span\"><i>n</i> × <i>n</i></span> square matrix, where each cell is a zone of the desert. The cell <span class=\"tex-span\">(<i>i</i>, <i>j</i>)</span> represents the cell at row <span class=\"tex-span\"><i>i</i></span> and column <span class=\"tex-span\"><i>j</i></span> <span class=\"tex-span\">(1 ≤ <i>i</i>, <i>j</i> ≤ <i>n</i>)</span>. Iahub can go from one cell <span class=\"tex-span\">(<i>i</i>, <i>j</i>)</span> only down or right, that is to cells <span class=\"tex-span\">(<i>i</i> + 1, <i>j</i>)</span> or <span class=\"tex-span\">(<i>i</i>, <i>j</i> + 1)</span>. </p><p>Also, there are <span class=\"tex-span\"><i>m</i></span> cells that are occupied by volcanoes, which Iahub cannot enter. </p><p>Iahub is initially at cell <span class=\"tex-span\">(1, 1)</span> and he needs to travel to cell <span class=\"tex-span\">(<i>n</i>, <i>n</i>)</span>. Knowing that Iahub needs <span class=\"tex-span\">1</span> second to travel from one cell to another, find the minimum time in which he can arrive in cell <span class=\"tex-span\">(<i>n</i>, <i>n</i>)</span>.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains two integers <span class=\"tex-span\"><i>n</i></span> <span class=\"tex-span\">(1 ≤ <i>n</i> ≤ 10<sup class=\"upper-index\">9</sup>)</span> and <span class=\"tex-span\"><i>m</i></span> <span class=\"tex-span\">(1 ≤ <i>m</i> ≤ 10<sup class=\"upper-index\">5</sup>)</span>. Each of the next <span class=\"tex-span\"><i>m</i></span> lines contains a pair of integers, <span class=\"tex-span\"><i>x</i></span> and <span class=\"tex-span\"><i>y</i></span> <span class=\"tex-span\">(1 ≤ <i>x</i>, <i>y</i> ≤ <i>n</i>)</span>, representing the coordinates of the volcanoes.</p><p>Consider matrix rows are numbered from 1 to <span class=\"tex-span\"><i>n</i></span> from top to bottom, and matrix columns are numbered from 1 to <span class=\"tex-span\"><i>n</i></span> from left to right. There is no volcano in cell <span class=\"tex-span\">(1, 1)</span>. No two volcanoes occupy the same location. </p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print one integer, the minimum time in which Iahub can arrive at cell <span class=\"tex-span\">(<i>n</i>, <i>n</i>)</span>. If no solution exists (there is no path to the final cell), print -1.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>4 2<br />1 3<br />1 4<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>6<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>7 8<br />1 6<br />2 6<br />3 5<br />3 6<br />4 3<br />5 1<br />5 2<br />5 3<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>12<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>2 2<br />1 2<br />2 1<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>-1<br /></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>Consider the first sample. A possible road is: <span class=\"tex-span\">(1, 1)</span> <span class=\"tex-span\"> → </span> <span class=\"tex-span\">(1, 2)</span> <span class=\"tex-span\"> → </span> <span class=\"tex-span\">(2, 2)</span> <span class=\"tex-span\"> → </span> <span class=\"tex-span\">(2, 3)</span> <span class=\"tex-span\"> → </span> <span class=\"tex-span\">(3, 3)</span> <span class=\"tex-span\"> → </span> <span class=\"tex-span\">(3, 4)</span> <span class=\"tex-span\"> → </span> <span class=\"tex-span\">(4, 4)</span>.</p></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=B]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== statementText) {\r\n $problem.find(\".diff-notifier\").show();\r\n\r\n $problem.find(\".diff-notifier-close\").click(function() {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n $problem.find(\".diff-notifier\").hide();\r\n });\r\n\r\n $problem.find(\"a.view-changes\").click(function() {\r\n $.post(\"/data/diff\", {action: \"getDiff\", a: previousStatementText, b: statementText}, function (result) {\r\n if (result[\"success\"] === \"true\") {\r\n Codeforces.facebox(\".diff-popup\", \"//codeforces.org/s/73366\");\r\n $(\"#facebox .diff-popup\").html(result[\"diff\"]);\r\n }\r\n }, \"json\");\r\n });\r\n }\r\n } else {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n }\r\n });\r\n });\r\n </script>\r\n\r\n\r\n<script type=\"text/javascript\">\r\n $(document).ready(function () {\r\n window.changedTests = new Set();\r\n\r\n function endsWith(string, suffix) {\r\n return string.indexOf(suffix, string.length - suffix.length) !== -1;\r\n }\r\n\r\n const inputFileDiv = $(\"div.input-file\");\r\n const inputFile = inputFileDiv.text();\r\n const outputFileDiv = $(\"div.output-file\");\r\n const outputFile = outputFileDiv.text();\r\n\r\n\r\n if (!endsWith(inputFile, \"standard input\")\r\n && !endsWith(inputFile, \"standard input\")) {\r\n inputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n if (!endsWith(outputFile, \"standard output\")\r\n && !endsWith(outputFile, \"standard output\")) {\r\n outputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n const titleDiv = $(\"div.header div.title\");\r\n\r\n\r\n\r\n String.prototype.replaceAll = function (search, replace) {\r\n return this.split(search).join(replace);\r\n };\r\n\r\n $(\".sample-test .title\").each(function () {\r\n const preId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n const cpyId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n\r\n $(this).parent().find(\"pre\").attr(\"id\", preId);\r\n const $copy = $(\"<div title='Copy' data-clipboard-target='#\" + preId + \"' id='\" + cpyId + \"' class='input-output-copier'>Copy</div>\");\r\n $(this).append($copy);\r\n\r\n const clipboard = new Clipboard('#' + cpyId, {\r\n text: function (trigger) {\r\n const pre = document.querySelector('#' + preId);\r\n const lines = pre.querySelectorAll(\".test-example-line\");\r\n return Codeforces.filterClipboardText(pre.innerText, lines.length);\r\n }\r\n });\r\n\r\n const isInput = $(this).parent().hasClass(\"input\");\r\n\r\n clipboard.on('success', function (e) {\r\n if (isInput) {\r\n Codeforces.showMessage(\"The example input has been copied into the clipboard\");\r\n } else {\r\n Codeforces.showMessage(\"The example output has been copied into the clipboard\");\r\n }\r\n e.clearSelection();\r\n });\r\n });\r\n\r\n $(\".test-form-item input\").change(function () {\r\n addPendingSubmissionMessage($($(this).closest(\"form\")), \"You changed the answer, do not forget to submit it if you want to save the changes\");\r\n const index = $(this).closest(\".problemindexholder\").attr(\"problemindex\");\r\n let test = \"\";\r\n $(this).closest(\"form input\").each(function () {\r\n const test_ = $(this).attr(\"name\");\r\n if (test_ && test_.substring(0, 4) === \"test\") {\r\n test = test_;\r\n }\r\n });\r\n if (index.length > 0 && test.length > 0) {\r\n const indexTest = index + \"::\" + test;\r\n window.changedTests.add(indexTest);\r\n }\r\n });\r\n\r\n $(window).on('beforeunload', function () {\r\n if (window.changedTests.size > 0) {\r\n return 'Dialog text here';\r\n }\r\n });\r\n\r\n autosize($('.test-explanation textarea'));\r\n\r\n $(\".test-example-line\").hover(function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n let top = 1E20;\r\n let left = 1E20;\r\n let problem = $(this).closest(\".problemindexholder\");\r\n $(this).closest(\".input\").find(\".\" + clazz).css(\"background-color\", \"#FFFDE7\").each(function() {\r\n top = Math.min(top, $(this).offset().top);\r\n left = Math.min(left, $(this).offset().left);\r\n });\r\n let testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n if (testCaseMarker.length === 0) {\r\n const html = \"<div class=\\\"testCaseMarker testCaseMarker_\" + end + \" notice\\\"></div>\";\r\n problem.append($(html));\r\n testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n }\r\n if (testCaseMarker) {\r\n testCaseMarker.show()\r\n .offset({top, left: left - 20})\r\n .text(end);\r\n }\r\n }\r\n }\r\n });\r\n }, function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n $(\".\" + clazz).css(\"background-color\", \"\");\r\n $(this).closest(\".problemindexholder\").find(\".testCaseMarker_\" + end).hide();\r\n }\r\n }\r\n });\r\n });\r\n\r\n });\r\n</script>\r\n\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 05:37:58</span> (j3).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/73366/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/73366/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/73366/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/73366/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-73366.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'8122c3e92b447b23',t:'MTY5NjY0NjI3OC42OTgwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"},"long_tags":{"kind":"string","value":"[\"Binary search\", \"Implementation problems, programming technics, simulation\", \"Sortings, orderings\", \"Two pointers\"]"},"short_tags":{"kind":"string","value":"[\"binary search\", \"implementation\", \"sortings\", \"two pointers\", \"*2500\"]"},"tutorial_link":{"kind":"string","value":"https://codeforces.com/blog/entry/10476"},"tutorial_page":{"kind":"string","value":"\r\n\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"4f4c31ed5807bbee2a02378cf0944c06\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"h1\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Codeforces Round #225 — Editorial - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n \n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Codeforces Round #225 — Editorial - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/81027/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/81027/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/81027/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/81027/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/81027/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/81027/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/81027/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/81027/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/81027/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/81027/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/81027/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/81027/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/81027/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/81027/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/573cedc6b04c15481941f418269f4057/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='4f4c31ed5807bbee2a02378cf0944c06'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/81027/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fblog%2Fentry%2F10476\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='4f4c31ed5807bbee2a02378cf0944c06'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Pay attention\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n <div style=\"text-align:center;border-bottom: 1px solid rgb(185, 185, 185);margin:0 -0.5em 0.5em -0.5em;padding: 0 1em 0.5em 1em;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 1, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:51:58</span><br/><a href=\"/contestRegistration/1876\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n <div style=\"text-align:center;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 2, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:51:58</span><br/><a href=\"/contestRegistration/1877\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n\r\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div>\r\n\r\n\n <div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\n\r\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='4f4c31ed5807bbee2a02378cf0944c06'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n </label>\r\n </div>\r\n <div style=\"padding: 0 1em 1em 1em;text-align:right;\">\r\n <input style=\"height:1.65em;padding:0 0.75em;\" type=\"submit\" value=\"Find\"/>\r\n </div>\r\n </form>\r\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".handleBox\").autocomplete(\"/data/handles\", {\r\n delay: 200,\r\n width: 200,\r\n selectFirst: false,\r\n matchContains: true,\r\n minChars: 3\r\n });\r\n $(\".handleForm\").attr(\"autocomplete\", \"off\").submit(function () {\r\n var link = \"/profile/userHandle\".replace(\r\n \"userHandle\", $(this).find(\".handleBox\").val()\r\n );\r\n window.location = link;\r\n return false;\r\n });\r\n });\n </script>\n\r\n\r\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Recent actions\n <div class=\"top-links\">\n </div>\n </div>\n <div class=\"recent-actions\">\r\n <ul>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/121073\">Meta Hacker Cup 2023 Round 1</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/.Danet\" title=\"Expert .Danet\" class=\"rated-user user-blue\">.Danet</a> →\r\n <a href=\"/blog/entry/121172\">[TLE on pretest1]</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\" class=\"rated-user user-red\">Pyqe</a> →\r\n <a href=\"/blog/entry/121025\">Codeforces Round #902 (Div. 1, Div. 2, based on COMPFEST 15 — Final Round)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pranshu_Pandya\" title=\"Specialist Pranshu_Pandya\" class=\"rated-user user-cyan\">Pranshu_Pandya</a> →\r\n <a href=\"/blog/entry/121171\">An Interesting Tree Problem</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/sszcdjr\" title=\"Master sszcdjr\" class=\"rated-user user-orange\">sszcdjr</a> →\r\n <a href=\"/blog/entry/119859\">Codeforces Round 896 (Div. 1, Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/119880\">It's Happening! Meta Hacker Cup 2023 Schedule</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/DaviddeGea1\" title=\"Expert DaviddeGea1\" class=\"rated-user user-blue\">DaviddeGea1</a> →\r\n <a href=\"/blog/entry/70917\">Number of ways of dividing an array into 2 parts such that sum of each part is > k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bekh\" title=\"Master Bekh\" class=\"rated-user user-orange\">Bekh</a> →\r\n <a href=\"/blog/entry/74245\">Questions and doubts regarding Aliens DP trick</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a> →\r\n <a href=\"/blog/entry/8192\">Codeforces Round #190 — Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/hocky\" title=\"Candidate Master hocky\" class=\"rated-user user-violet\">hocky</a> →\r\n <a href=\"/blog/entry/95323\">FBHC wuining uw Day? Incwease uw stacc size! (ㅅ´ ˘ `)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/liouzhou_101\" title=\"International Master liouzhou_101\" class=\"rated-user user-orange\">liouzhou_101</a> →\r\n <a href=\"/blog/entry/87598\">Editorial of Codeforces Round #700</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/yeon_gist\" title=\"Newbie yeon_gist\" class=\"rated-user user-gray\">yeon_gist</a> →\r\n <a href=\"/blog/entry/121170\">plusMinusPermutation computing error</a>\r\n <img alt=\"Text created or updated\" title=\"Text created or updated\" src=\"//codeforces.org/s/81027/images/icons/x-update-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/altforminuscontribution\" title=\"Newbie altforminuscontribution\" class=\"rated-user user-gray\">altforminuscontribution</a> →\r\n <a href=\"/blog/entry/121162\">My screen get unexpectedly big, what should I do</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/atcoder_official\" title=\"Unrated, atcoder_official\" class=\"rated-user user-black\">atcoder_official</a> →\r\n <a href=\"/blog/entry/121120\">We will hold UNIQUE VISION Programming Contest 2023 Autumn(AtCoder Beginner Contest 323)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/YouStill_DontKnowMeYet\" title=\"Candidate Master YouStill_DontKnowMeYet\" class=\"rated-user user-violet\">YouStill_DontKnowMeYet</a> →\r\n <a href=\"/blog/entry/117659\">[GYM] Al-Baath Collegiate Programming Contest 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/ankancool\" title=\"Expert ankancool\" class=\"rated-user user-blue\">ankancool</a> →\r\n <a href=\"/blog/entry/121136\">Invitation to AstroByte 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/GeZhiyuan\" title=\"Grandmaster GeZhiyuan\" class=\"rated-user user-red\">GeZhiyuan</a> →\r\n <a href=\"/blog/entry/120943\">Codeforces Round 901 (Div. 1, Div. 2) Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a> →\r\n <a href=\"/blog/entry/120772\">PSA: Increase your stack size before the Meta Hacker Cup, here's how</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/dino_merlin\" title=\"Expert dino_merlin\" class=\"rated-user user-blue\">dino_merlin</a> →\r\n <a href=\"/blog/entry/121145\">Intuitive approach for CEOI Kangaroo?</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/icecuber\" title=\"Grandmaster icecuber\" class=\"rated-user user-red\">icecuber</a> →\r\n <a href=\"/blog/entry/70018\">CSES DP section editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bn00b\" title=\"Newbie Bn00b\" class=\"rated-user user-gray\">Bn00b</a> →\r\n <a href=\"/blog/entry/98820\">[FEATURE REQUEST : ATCODER] TOPICS TAGS AND SORTING BY SOLVE COUNT</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a> →\r\n <a href=\"/blog/entry/121163\">AtCoder Regular Contest 166 Announcement</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/windva\" title=\"Grandmaster windva\" class=\"rated-user user-red\">windva</a> →\r\n <a href=\"/blog/entry/120644\">Codeforces Round 899 (Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Misa-Misa\" title=\"Expert Misa-Misa\" class=\"rated-user user-blue\">Misa-Misa</a> →\r\n <a href=\"/blog/entry/121157\">Someone please help me understand this.</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/shivam565\" title=\"Specialist shivam565\" class=\"rated-user user-cyan\">shivam565</a> →\r\n <a href=\"/blog/entry/108348\">Total number of subarrays with sum atmost k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n </ul>\r\n </div>\r\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/recent-actions\">Detailed →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n</div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li><a\r\n href=\"/profile/fchirica\">fchirica</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/fchirica\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/fchirica\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/fchirica\">Submissions</a></li>\r\n <li><a\r\n href=\"/groups/with/fchirica\">Groups</a></li>\r\n <li><a\r\n href=\"/contests/with/fchirica\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/fchirica\">Problemsetting</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/fchirica\" style=\"text-decoration:none;color:black !important;\">fchirica's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"10531\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/10476\"> <p>Codeforces Round #225 — Editorial</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/fchirica\" title=\"Candidate Master fchirica\" class=\"rated-user user-violet\">fchirica</a>,\r\n <span class=\"format-humantime\" title=\"Jan/20/2014 22:18\">10 years ago</span>,\r\n \r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><h1><a href=\"/contest/384/problem/A\" title=\"Codeforces Round 225 (Div. 2)\">384A - Coder</a></h1><p>Usually, when you don’t have any idea how to approach a problem, a good try is to take some small examples.</p><p>So let’s see how it looks for N = 1, 2, 3, 4 and 5. With C I noted the coder and with * I noted an empty cell.</p><p><img alt=\" \" src=\"/predownloaded/8f/89/8f899efd227362957f283123a7927c7c8a300667.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>By now you should note that answer is N ^ 2 / 2 when N is even and (N ^ 2 + 1) / 2 when N is odd. Good. Generally, after you find a possible solution by taking examples, you need to prove it, then you can code it.</p><p>In order to proof it, one needs to do following steps:</p><p>1/ prove you can always build a solution having N ^ 2 / 2 (or (N ^ 2 + 1) / 2) pieces.</p><p>2/ prove that N ^ 2 / 2 (or (N ^ 2 + 1) / 2) is maximal number – no other bigger solution can be obtained.</p><p>For proof 1/ imagine you do coloring like in a chess table.</p><p><img alt=\" \" src=\"/predownloaded/50/12/50120d92bd0cea3d6a434d09ab4754ea20342351.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>The key observation is that by placing all coders on black squares of table, no two coders will attack. Why? Because a piece placed at a black square can attack only a piece placed at a white square. Again, why? Suppose chess table is 1-based. Then, a square (i, j) is black if and only if i + j is even. A piece placed at (i, j) can attack (i + 1, j), (i – 1, j) (i, j + 1) or (i, j – 1). The sum of those cells is i + j + 1 or i + j – 1. But since i + j is even, i + j + 1 and i + j – 1 are odd, hence white cells.</p><p>Depending on parity of N, number of black cells is either N ^ 2 / 2 or (N ^ 2 + 1) / 2. For N even, one can observe that there are equal amount of black and white cells. Total number of cells is N ^ 2, so number of black cells is N ^ 2 / 2. For N odd, number of black cells is number of white cells + 1. We can imaginary add a white cell to the board. Now, number of black cells will be also equal to number of white cells, so answer is (N ^ 2 + 1) / 2.</p><p>2/ Two coders attack each other if they are placed at two adjacent cells, one black and other one white. One needs to prove that adding more than number from 1/ will cause this to happen. If you place a coder at a white cell, you won’t be able to place at least one coder at a black cell, so in best case you don’t win anything by doing this. Hence, it’s optimally to place all coders on same color cells. Since cells colored in black are always more or equal to white ones, it’s always optimally to choose black color. But number from 1/ is the number of cells having black color. Adding one more piece will force you to add it to a white color cell. Now, you’ll have a piece placed at a black colored cell and one placed at an adjacent white colored cell, so two coders will attack. Hence, we can’t place more than number from 1/ pieces.</p><p>Code: <a href=\"http://pastie.org/8651801\">http://pastie.org/8651801</a></p><h1><a href=\"/contest/384/problem/B\" title=\"Codeforces Round 225 (Div. 2)\">384B - Multitasking</a></h1><p>Let’s start by saying when array A[] is sorted:</p><p>1/ is sorted in ascending order when i < j and A[i] <= A[j]. It is NOT sorted when i < j and A[i] > A[j].</p><p>2/ is sorted in descending order when i > j and A[i] <= A[j]. It is NOT sorted when i > j and A[i] > A[j].</p><p>Iahub can choose 2 indices i, j and swap values when A[i] > A[j]. If A[i] <= A[j], he’ll ignore operation. Hence, if he wants to sort all arrays in ascending order, he chooses indices i, j when i < j and perform operation. Otherwise, in all his operations he uses indices i, j such as i > j. A “good” operation is when choosing indices i < j for ascending order sorting and i > j for descending order sorting. By doing only good operations, after an array is sorted, it will stay sorted forever (for a sorted array, all good operations will be ignored).</p><p>From here we get our first idea: use any sorting algorithm you know and sort each array individually. When print swaps done by sorting algorithm chosen, print them as good operations. However, sorting each array individually can cause exceeding M * (M — 1) / 2 operations limit. Another possible solution would be, after you did an operation to an array, to update the operation to all arrays (you printed it, so it counts to M * (M — 1) / 2 operations limit; making it to all arrays will help sometimes and in worst case it won’t change anything). However, you need to code it very careful in order to make this algorithm pass the time limit. Doing this in a contest is not the best idea, especially when implementation could be complicated and you have no guarantee it will pass time limit.</p><p>So what else can we do? We can think out of box. Instead of sorting specific N arrays, you can sort all possible arrays of length M. Find a sequence of good operations such as, anyhow I’d choose an array of size M, it will get sorted ascending / descending.</p><p>I’ll show firstly how to do for ascending sorting. At position 1 it needs to be minimal element. Can we bring minimal element there using good operations? Yes. Just do “1 2” “1 3” “1 4” ... “1 M”. It basically compares element from position 1 to any other element from array. When other element has smaller value, swap is done. After comparing with all M elements, minimal value will be at position 1. By now on I’ll ignore position 1 and move to position 2. Suppose array starts from position 2. It also needs minimal value from array, except value from position 1 (which is no longer in array). Hence doing “2 3” “2 4” “2 5” ... “2 M” is enough, by similar reasons. For a position i, I need minimal value from array, except positions 1, 2, ..., i – 1. I simply do “i i+1” “i i+2” ... “i M-1” “i M”. By arriving at position i, array will be sorted ascending. The algorithm is simply:</p><p>for (int i = 1; i < M; ++i)</p><p>for (int j = i + 1; j <= M; ++j)</p><p>cout << i << “ “ << j << “\\n”;</p><p>This algorithm does exactly M * (M — 1) / 2 moves.</p><p>Can you find out how to sort array in descending order? Try to think yourself, then if you don’t get it read next. At first position of a descending array it needs to be maximal value. Similarly to ascending order, we can do “2 1” “3 1” “4 1” ... “M 1”. When I’m at a position i and I compare its value to value from position 1, doing operation “i 1” checks if A[i] > A[1]. If so, it swaps A[i] and A[1], so position 1 will contain now the maximum value so far. Similarly to logic from ascending order, when I’m at position i, I need maximum value from array except positions 1, 2, ..., i – 1, so I do “i+1 i” “i+2 i” ... “M i”. Algorithm is:</p><p>for (int i = 1; i < M; ++i)</p><p>for (int j = i + 1; j <= M; ++j)</p><p>cout << j << “ “ << i << “\\n”;</p><p>Obviously, this does as well M * (M — 1) / 2 operations worst case. All algorithm is about 10 lines of code, much better than other solution, which requires two manually sorts and also has a chance to exceed TL.</p><p>Code: <a href=\"http://pastie.org/8651809\">http://pastie.org/8651809</a></p><h1><a href=\"/contest/384/problem/C\" title=\"Codeforces Round 225 (Div. 2)\">384C - Milking cows</a></h1><p>A good strategy to approach this problem is to think how optimal ordering should look like. For this, let’s calculate for each 2 different cows i and j if cow i needs to be milked before or after cow j. As we’ll show, having this information will be enough to build optimal ordering. It is enough to consider only cases when i < j, case when i > j is exactly the opposite of case i < j. For formality, I’ll call the optimal ordering permutation and lost milk the cost of permutation.</p><p>So, for an optimal permutation P let’s take 2 numbers i < j and see in which cases i should appear before j in permutation (i is before j if P[pos1] = i, P[pos2] = j and pos1 < pos2; otherwise we’ll call i is after j). We have 4 possible cases:</p><p>1/ A[i] = 0 and A[j] = 0</p><p>If we put i before j, no additional cost will be added. Since j is in right of i and i only adds cost when it finds elements in left of i, j won’t be affected when processing i. When processing j, i will be already deleted so it won’t affect the cost either. Hence, we can put i before j and no cost will be added.</p><p>2/ A[i] = 0 and A[j] = 1</p><p>Here, i and j can appear in arbitrary order in permutation (i can be before or after j). No matter how we choose them, they won’t affect each other and cost will remain the same.</p><p>3/ A[i] = 1 and A[j] = 0</p><p>As well, here i and j can appear in arbitrary order. If we choose i first, j will be in right of it, so cost of permutation will increase by one. If we choose j first, i will be in left of it so cost of permutation will increase as well. No matter what we do, in this case cost of permutation increases by 1.</p><p>4/ A[i] = 1 and A[j] = 1</p><p>Here, i needs to be after j. This adds 0 cost. Taking i before j will add 1 cost to permutation (since j is in right of i).</p><p>Those 4 cases show us how a minimal cost permutation should look. In a permutation like this, only case 3/ contributes to final cost, so we need to count number of indices i, j such as i < j and A[i] = 1 and A[j] = 0 (*). If we show a permutation following all rules exists, task reduces to (*).</p><p>By cases 2/ and 3/ it follows that in an optimal permutation, it only matters order of elements having same value in A[]. We can put firstly all elements having value 0 in A[], then all elements having value 1 in A[]. We can order elements having value 0 by case 1/ and elements having value 1 by case 4/. More exactly, suppose i1 < i2 < ... < im and (A[i1] = A[i2] = ... = A[im] = 0) and j1 > j2 > ... > jn (A[j1] = A[j2] = ... = A[jn] = 1). Then, a permutation following all rules is {i1, i2, ..., im, j1, j2, ..., jn}. This permutation can always be built.</p><p>Hence, task reduces to (*): count number of indices i, j such as i < j and A[i] = 1 and A[j] = 0. We can achieve easily an O(N) algorithm to do this. Let’s build an array cnt[j] = number of 0s in range {j, j + 1, ..., N} from array A. We can easily implement it by going backwards from N to 1. The result is sum of cnt[i], when A[i] = 1.</p><p>Code: <a href=\"http://pastie.org/8651813\">http://pastie.org/8651813</a></p><h1><a href=\"/contest/384/problem/D\" title=\"Codeforces Round 225 (Div. 2)\">384D - Volcanoes</a></h1><p>Our first observation is that if there is a path from (1, 1) to (N, N), then the length of path is 2 * N – 2. Since all paths have length 2 * N – 2, it follows that if there is at least one path, the answer is 2 * N – 2 and if there isn’t, the answer is -1. How to prove it? Every path from (1, 1) to (N, N) has exactly N – 1 down directions and exactly N – 1 right directions. So, total length for each path is N – 1 + N – 1 = 2 * N – 2. </p><p>So we reduced our problem to determine if there is at least one path from (1, 1) to (N, N). This is the challenging part of this task, considering that N <= 10 ^ 9. How would you do it for a decently small N, let’s say N <= 10^3 . One possible approach would be, for each row, keep a set of reachable columns. We could easily solve this one by doing this: if (i, j) denotes element from ith row and jth column, then (i, j) is (is not) reachable if:</p><p>if (i, j) contains a volcano, then (i, j) is not reachable. Otherwise, if at least one of (i – 1, j) and (i, j – 1) is reachable, then (i, j) is reachable. Otherwise, (i, j) is not reachable.</p><p>What’s the main problem of this approach? It needs to keep track of 10^9 lines and in worst case, each of those lines can have 10^9 reachable elements. So, worst case we need 10^9 * 10^9 = 10^18 operations and memory.</p><p>Can we optimize it? We can note for beginning that we don’t need to keep track of 10^9 lines, only m lines are really necessarily. We need only lines containing at least one obstacle (in worst case when each line contains only one obstacle, we need m lines). How to solve it this way? Suppose line number x contains some obstacles and lines x + 1, x + 2, x + 3 do not contain any obstacle. Suppose we calculated set S = {y | cell (x, y) is reachable}. How would look S1, S2, S3 corresponding to lines x + 1, x + 2, x + 3? For S1, we can reach cell (x + 1, ymin), where ymin is minimal value from set S. Then, we can also reach {ymin + 1, ymin + 2, ..., N}, by moving right from (x + 1, ymin). So S1 = {ymin, ymin + 1, ..., N}. How do S2 and S3 look? It’s easy to see that they’ll be as well {ymin, ymin + 1, ..., N}. So we get following optimization: suppose set of lines containing at least one obstacle is {L1, L2, ..., Lk}. We need to run algorithm only for lines L1, L1 + 1, L2, L2 + 1, L3, L3 + 1, ..., Lk, Lk + 1.</p><p>It looks like we didn’t make anything with this optimization. Even if we calculate for m lines, each line can still have 10^9 reachable positions. So worst case we perform 10^14 operations. We need something better for managing information from a line. You can note that for a given line y, there are a lot of positions having consecutive values. There are a lot of positions (x, y) and (x, y + 1) both reachable. This should give us following idea: what if instead of keeping reachable positions, we keep reachable ranges? That is, for each line x we keep a set of ranges S = {(a, b) | all cells (x, k) with a <= k <= b are reachable}. </p><p>How many ranges can it be for a line? If the line contains m obstacles, there are m + 1 ranges. Suppose for line x all cells are reachable, but for line x + 1 cells (x + 1, 3) (x + 1, 5) (x + 1, N – 1) are blocked. Then, the ranges of reachable cells are [1, 2] [4, 4], [6, N – 2] and [N, N]. By now, we get worst case m lines and worst case each line having m elements, so in worst case we’d have to handle m * m = 10 ^ 10 events. This may still look too much, but happily this bound is over estimated. If a line has o obstacles, there can be at most o + 1 ranges. If lines L1, L2, ..., Lk have {o1, o2, ..., ok} obstacles, there’ll be at most o1 + o2 + ... + ok + k ranges. But o1 + o2 + ... + ok = m and also k is at most m (proved above why we’re interested in at most m lines), so in worst case we get m + m = 2 * m ranges. Yaay, finally a decent number of states for this problem :)</p><p>So, we iterate each line we’re interested in. Let’s find set of ranges for this line, thinking that all cells from line above are reachable. This is easy to do. After we get our ranges like all cells from above can be visited, let’s think how having obstacles above can influence current ranges. After adding ranges from above, current ranges can’t increase (obviously), they can only decrease, remain the same or some of them can become empty. So, let’s take each range [a, b] from current line and see how it will transform after adding ranges from previous line. </p><p>Given range [a, b], it can transform only in [a’ , b] with a’ >= a. If a’ > b, then obviously range is empty. Why second number of range keeps constant? Let a’ smallest reachable column from current line which is in range [a, b]. It’s enough to check a’ >= a, as if a’ > b, range will be empty. It’s obviously why we need to keep a’ smallest value possible >= a: we’re interested to keep range as big as possible and as less as we cut from left, as big it is. Once we’ve found a’ in range [a, b] (or a’ > b if range is empty) all cells {a’ + 1, a’ + 2, ..., b} are reachable as well by going right from a’, so if interval is not empty, then second number defining it remains b.</p><p>Next question is how to find a’ fast enough. In order a point a’ to be reachable on current range, it also needs to exist a range on previous line containing it. If the range from previous line is [pa, pb] then a’ needs to follow 3 conditions:</p><p>a’ minimal such as</p><p>pa <= a’ <= pb</p><p>a’ >= a</p><p>What if instead of finding a’ we find [pa, pb]? Then a’ is max(pa, a). In order a’ to be as small as possible, since a is constant, pa needs to be as small as possible. So we reduced it to:</p><p>pa minimal pb >= a’ >= a <=> pb >= a</p><p>Intervals from previous line are disjoint, no 2 intervals cross each other. It means that if pb is minimal, than pa is minimal too (if we increase pb, then pa will increase too, so it won’t be minimal). Hence, you need to find an interval [pa, pb] such as pb is minimal and pb >= a. Then, a’ is max(a, pa). This is easy to do if we sort all intervals from previous line increasing by second value (pb), then we binary search for value a. </p><p>Finally, after running algorithm for all lines, last range from last line has second number N (assuming ranges are sorted increasing by second value), then there exist a path, otherwise there does not exist. This algorithm should run O(m * logm) worst case, good enough to pass. </p><p>Code: <a href=\"http://pastie.org/8651817\">http://pastie.org/8651817</a></p><h1><a href=\"/contest/384/problem/E\" title=\"Codeforces Round 225 (Div. 2)\">384E - Propagating tree</a></h1><p>This is kind of task that needs to be break into smaller subproblems that you can solve independently, then put them together and get solution.</p><p>Let’s define level of a node the number of edges in the path from root to the node. Root (node 1) is at level 0, sons of root are at level 1, sons of sons of root are at level 2 and so on.</p><p>Now suppose you want to do an operation of type 1 to a node x. What nodes from subtree of x will be added +val (a positive value)? Obviously, x will be first, being located at level L. Sons of x, located at level L + 1 will be added –val. Sons of sons, located at level L + 2, will be added value +val again. So, nodes from subtree of x located at levels L, L + 2, L + 4, ... will be added a +val, and nodes located at levels L + 1, L + 3, L + 5 will be added a –val. Let’s take those values of L modulo 2. All nodes having remainder L modulo 2 will be added a +val, and nodes having reminder (L + 1) modulo 2 will be added –val. In other words, for a fixed x, at a level L, let y a node from subtree of x, at level L2. If L and L2 have same parity, +val will be added to y. Otherwise, -val will be added to y.</p><p>From here we have the idea to split nodes of tree in 2 sets – those being located at even level and those being located at odd level. What still makes the problem hard to solve? The fact that we have a tree. If nodes from a subtree would be a contiguous sequence instead of some nodes from a tree, problem would be simpler: the problem would reduce to add / subtract values to all elements of a subarray and query about a current value of an element of array. So, how can we transform tree to an array, such as for a node x, all nodes from subtree of x to be a subarray of array?</p><p>The answer is yes. We can do this by properties of DFS search. Before reading on, make sure that you know what is discovery time and finish time in a DFS search. Let’s build 3 arrays now – discover[], representing nodes in order of their discover times (a node is as before in discover as it has a small discover time), begin[] = for a node, in which time it was discovered and end[] = what’s last time of a discovered node before this node finishes. For a subtree of x, all nodes in the subtree are nodes in discover from position begin[x] to end[x].</p><p>Example: suppose you have tree 1-5; 1-6; 6-7; 6-4; 4-2; 4-3</p><p>Discover is {1, 5, 6, 7, 4, 2, 3}.</p><p>begin is {1, 6, 7, 5, 2, 3, 4}.</p><p>end is {7, 6, 7, 7, 2, 7, 4}.</p><p>What’s subtree of node 6? elements of discover from position begin[6] to end[6]. In this case, from 3 to 7, so elements {6, 7, 4, 2, 3}. You can see it’s correct and take more examples if you want :)</p><p>Now, we reduced problem to: you’re given an array A. you can perform 2 operations:</p><p>1/ increase all elements from a range [x, y] to a value val (val can be negative, to treat subtractions)</p><p>2/ what’s current value of an element from position pos.</p><p>Those who solved “Iahub and Xors” from my last round, CF 198, should probably say they saw something similar before. If you didn’t solve problem before, I encourage you to do it after you solve this one, it uses a similar idea to what will follow now. Also, if you don’t know Fenwick trees, please read them before moving on. An alternative would be for this task using segment trees with lazy update, but I see this one more complicated than needed.</p><p>I’ll use now a not so common approach when dealing with data structures. Instead of keeping in a node the result, like you usually do, I’ll keep just an auxiliary information. So what algorithm proposed does:</p><p>Let A an array, initially with all elements 0.</p><p>When you need to update range [x, y] with value val, you simply do A[x] += val and A[y + 1] -= val.</p><p>When you need to answer a query about position pos, you output A[1] + A[2] + ... + A[pos].</p><p>Implemented brute force, you get O(1) per update and O(N) per query. However, these both are operations supported by a Fenwick tree, so you can get O(logN) per operation.</p><p>It may not be very clear why this algorithm works. Let’s take a closer look: an update needs to add value val only to range [x, y]. When you query a position pos, let’s see if algorithm handles it correctly:</p><p>1/ pos < x. In this case, result must not be affected by my update. Since pos < x and I only updated 2 values with indices >= x, when doing A[1] + A[2] + ... + A[pos] it won’t matter at all I did that update – at least not for this query.</p><p>2/ x <= pos <= y. Here, for a pos, I need to add value val only once. We add it only at A[x] – in this way it will be counted once, and it will be considered for each elements from range [x, y] (since an element at position p from range [x, y] has p >= x, in A[1] + A[2] + ... + A[p] I’ll have to consider A[x]).</p><p>3/ pos > y. Here I don’t have to consider the query. But it would be considered when processing A[x]. But if I add to A[y + 1] value –val I’ll just cancel the value previously added.</p><p>Code (actually we use just one Fenwick tree instead of 2, can you think why it works? :) ) : <a href=\"http://pastie.org/8651824\">http://pastie.org/8651824</a></p><h1><a href=\"/contest/383/problem/D\" title=\"Codeforces Round 225 (Div. 1)\">383D - Antimatter</a></h1><h2>Author's solution</h2><p>The problem is: given an array, iterate all possible subarrays (all possible elements such as their indexes are consecutive). Now, for a fixed subarray we need to know in how many ways we can color its elements in black and white, such as sum of black elements is equal to sum of white elements. The result is sum of this number, for each subarray.</p><p>Let’s solve an easier problem first. This won’t immediately solve the harder version, but it will be useful later. Suppose you’ve fixed a subarray. In how many ways can you color it with black and white? Suppose subarray has N elements and sum of them is M. Also, suppose for a coloring, sum of blacks is sB and sum of whites is sW. For coloring to be valid, sB = sW. But we also know that sB + sW = M (because each element is colored by exactly one color). We get that 2 * sB = M, so sB = M / 2. The problem is now: in how many ways can we color elements in black such as sum of blacks is M / 2 (after we fix a black coloring, we color with white non colored elements; sum of white colored elements is also M / 2). This is a well known problem: Knapsack problem. Let ways[i][j] = in how many ways one can obtain sum j from first i elements. When adding (i + 1) object, after ways[i] is calculated, for a fixed sum j we can do 2 things: add (i + 1) object to sum j or skip it. Depending of what we chosen, we add value ways[i][j] to ways[i + 1][j + value[i + 1]] or to ways[i + 1][j]. The result is in ways[N][M / 2]. This works in O(N * M) time.</p><p>An immediate solution can be obtained now: take all subarrays and apply above approach. This leads to an O(N ^ 2 * M ^ 2) solution, which is too much. One can reduce complexity to O(N ^ 2* M) by noting that processing subarray [i, j] can be done with already calculated values for subarray [i, j – 1]. Hence, instead of adding N elements, it’s enough to add 1 element to already calculated values (element from position j). Sadly, O(N ^ 2 * M) is still too slow, so we need to find something better. The solution presented below will look forced if you didn’t solve some problems with this technique before. It’s hard to come with an approach without practicing this kind of tasks. But don’t worry, as much as you practice them, as easily you’ll solve those problems.</p><p>We’ll solve task by divide and conquer. Complexity of this solution is O(N * M * logN). Let f(left, right) a function that counts number of colorings for each subarray [i, j], such as subarray [i, j] is included in subarray [left, right] (left <= i <= j <= right). Answer is in f(1, N). The trick is to define a value med = (left + right) / 2 (very frequent trick in divide and conquer problems, called usually a median). We can next classify [i, j] subarrays in 3 types:</p><p>1/ i <= med j <= med</p><p>2/ i > med j > med</p><p>3/ i <= med j > med</p><p>We can solve 1/ and 2/ by calling f(left, med) and f(med + 1, right). The remained problem is when i <= med and j > med. If we solve 3/ in O((right – left) * M) time, this will be enough to overall achieve O(N * M * logN) (for this moment trust me, you’ll see later why it’s so :) ).</p><p>Let’s denote by i1 last i1 elements from subarray [left, med]. Also, let’s note by i2 first i2 elements from subarray [med + 1, right]. For example, let left = 1 and right = 5, with array {1, 2, 3, 4, 5}. med is 3 and for i1 = 2 and i2 = 1, “left” subarray is {2, 3} and “right” subarray is {4}. By iterating i1 from 1 to med – left + 1 and i2 from 1 to right – med and then unite subarrays i1 and i2, we obtain all subarrays described in 3/ . Let’s denote by j1 sum of a possible black coloring of i1. Similarly, j2 is sum of a possible black coloring of i2.</p><p>Suppose we fixed i1, i2, j1 and j2. When it’s the coloring valid? Let S sum of united subarrays i1 and i2 (S = value[med – i1 + 1] + value[med – i1 + 2] + ... + value[med] + value[med + 1] + ... + value[med + i2 – 1] + value[med + i2]). Now it’s time to use what I explained at the beginning of solution. The coloring is good only when j1 + j2 = S / 2. We can rewrite the relation as 2 * (j1 + j2) = sum_of_elements_from_i1 + sum_of_elements_from_i2. We can rewrite it even more:</p><p>2 * j1 + 2 * j2 — sum_of_elements_from_i1 — sum_of_elements_from_i2 = 0</p><p>2 * j1 – sum_of_elements_from_i1 = sum_of_elements_from_i2 – 2 * j2 = combination_value</p><p>This relation is the key of solving problem. You can see now that relation is independent in “left” and “right” side. We calculate left[i1][j1] and right[i2][j2] = in how many ways can I obtain sum of blacks j1 (j2) from first i1 (i2) from left (right) side. Let’s calculate also count[value] = in how many ways can I obtain combination_value equal to value in the right side. For some fixed (i2, j2) I add to count[sum_of_elements_from_i2 – 2 * j2] value right[i2][j2]. In this way count[] is calculated correctly and completely. Now, let’s fix a sum (i1, j1) in the left side. We’re interested how many good colorings are such as there exist a coloring of j1 in i1 elements (the endpoint of “left” is fixed to be i1 and I need to calculate endpoints i2 for right, then to make colorings of i2). A coloring is good if combination_value of (i1, j1) and (i2, j2) is equal. Hence, I need to know in how many ways I can color i1 elements to obtain sum j1 and also I need to know in how many ways I can color elements from right to obtain same combination_value as it’s in the left. It’s not hard to see that answer for a fixed (i1, j1) is left[i1][j1] * count[2 * j1 – sum_of_elements_from_i1]. This takes O((right – left) * M) time.</p><p>The only thing remained in the problem is to see why complexity is O(N * M * logN). We can assume N is a power of 2 (it not, let’s round N to smallest power of 2 bigger than N; complexity for N is at least as good as complexity for this number). Draw a binary complete tree with N nodes. Each node corresponds to an appeal of f(). For a level, exactly O(N * M) operations are performed. To see why:</p><p>For level 1, there’ll be 1 node performing N * M operations.</p><p>For level 2, there’ll be 2 nodes performing (N / 2) * M operations. Summing up we get O(N * M).</p><p>For level 3, there’ll be 4 nodes performing (N / 4) * M operations. Summing up we get O(N *M) as well.</p><p>and so on.</p><p>So for each level we perform O(N * M) operations. A binary complete tree has maximum O(logN) levels, so overall complexity is O(N * M * logN).</p><p>Code: <a href=\"http://pastie.org/8651826\">http://pastie.org/8651826</a></p><h2>Solution fount by contestants</h2><p>This was totally unexpected to us :) Good job finding it, you guys are really smart. </p><p>We observe that x units of antimatter is the same thing as -x units of matter. Then we can consider that an element produces either x or -x units of matter. A valid substring is one that can have the sum of the elements 0. The problem is reduced to finding how many different substrings can we have with sum 0 (a substring is different than another one if it has different indices, or if at least one element produces matter in one and antimatter in the other).</p><p>This problem can be solved with dynamic programming. We will hold D[i][j] = the number of substrings that end in element i, and have sum j. It's easy to see that D[i + 1][j] = D[i][j — x] + D[i][j + x], where x is the value of the current element (we can put either -x or x). After we finish computing all the values for current i, we add to the solution D[i][0] (how many valid substrings do we have). After that, we add 1 to D[i][0], meaning that there is an empty substring starting at position i (however, we don't need to add it to the answer).</p><p>For a code, check passing submissions during contest. </p><h2><a href=\"/contest/383/problem/E\" title=\"Codeforces Round 225 (Div. 1)\">383E - Vowels</a></h2><h2>Author's solution</h2><p>Let's iterate over all possible vowel sets. For a given set {x1, x2, ..., xk} we're interested in number of correct words from dictionary. After a precalculation, we can do it in O(k).</p><p>Suppose our current vowel set is {x1, x2, ..., xk}. How many words are covered by the current vowels? By definition, we say a word is covered by a set of vowels if at least one of 3 letters of word is in vowel set. We can calculate this number using principle of inclusion and exclusion. We’ll denote by |v1, v2, v3, ...| = number of words containing ALL of vowels v1, v2, v3, ... . Using principle of inclusion and exclusion we get:</p><p>number_of_words_covered = |x1| + |x2| + .. + |xk| — |x1, x2| — |x1, x3| — .... + |x1, x2, x3| + |x1, x2, x4| + .... + |xk-2, xk-1, xk|. This formula is simply a reformulation of principle of inclusion and exclusion. You can easily observe that |v1, v2, ..., vk| makes sense only when k is at most 3, as no word from input can contain 4 or more letters (and hence can’t contain 4 or more vowels). </p><p>Example:</p><p>Suppose words are abc, abd and bcd. </p><p>|a| = 2 (first 2 words both contain character a).</p><p>|a, b| = 2 (as well, first 2 words contain characters a and b).</p><p>|b| = 3 (all 3 words contain character b).</p><p>|a, b, d| = 1 (only second word contains all 3 characters).</p><p>Also, note how principle of inclusion and exclusion works. number of words covered for vowels {a, b} is |a| + |b| — |a, b| = 2 + 3 – 2. Indeed, answer is 3.</p><p>We divide our problem in 3 subproblems. First one, for a vowel set, compute sum of |a|, where a is a letter from subset. Second, compute sum of |a, b|, where both a and b are letters from set. Third, compute sum of |a, b, c|, where a, b, c are letters from set. As stated, the answer is number_from_1st_step + number_from_3rd_step – number_from_2nd_step. If you followed me, you’ll see that we want to compute results for each subproblem in O(queryLetters).</p><p>First subproblem can be solved trivially in O(queryLetters). Let array single[], with following meaning: single[c] is how many words contain character c. It can be trivially precomputed in O(24 * N). Note that if a word contains twice/third times a character c, it needs to be counted only one (e.g. word aba will add only 1 to single[a]). For compute result of this subproblem for a given set of vowels, I’ll take all letters from set. If letter belongs to set, I add to result single[letter]. This step can be also be solved in O(1), but there’s no need, since other subproblems allow only an O(queryLetters) solution. </p><p>For second and third subproblems it’s a little more difficult. I’ll present here how to solve second subproblem and some hints for third one (if you understand second, with hints you should be able to solve third one by your own).</p><p>Similarly to first step, I’ll define a matrix double[c1][c2] = how many words contain both characters c1 and c2. A trivially solution would be, for a given vowel set, take all combinations of letters c1 and c2 that belong to set and add to result value double[c1][c2]. However, this solves each query in O(queryLetters^2), which is too slow.</p><p>Note, if we’d have 12 letters, instead of 24, this approach would be fast enough. From here it comes a pretty classical idea in exponential optimization: meet in the middle attack. We split those 24 letters in 2 groups: first 12 letters and last 12 letters. The answer for a subset is sum of double[c1][c2] (when c1 and c2 belong to current vowel set) when</p><p>1/ c1 and c2 belong to first 12 letters</p><p>2/ c1 and c2 belong to last 12 letters</p><p>3/ c1 belongs to first 12 letters and c2 belongs to last 12 letters</p><p>1/ and 2/ can be immediately precalculated as stated above, in O(2 ^ 12 * 12 ^ 2). We’ll remember results for each half using bitmasks arrays. Let Half1[mask] = sum over double[c1][c2], when c1 and c2 are in first 12 letters and correspond to 1 bits of mask. Half2[mask] is defined similarly, but for last 12 letters (e.g. subset {a, c, d} corresponds to bitmask 2^0 + 2^2 + 2^3 = 13 in first half and subset {m, n, p} corresponds to bitmask 2^0 + 2^1 + 2^3 = 11 for second half). Now, for a given subset, one can answer first 2 parts in O(queryCount) worst case (read input for a query and convert it to bitmasks). </p><p>How to answer 3? With another precalculation, of course. We know c1 letter needs to be in first 12 letters and c2 needs to be in last 12 letters. The precalculation we do here is: mixed_half[mask][i] = sum over |c1, c2|, when c1 belongs to first half and is a 1 bit of mask and c2 is i-th character of second half. Hence, for a query, we can fix character from second half (c2, by iteration of query letters from second half) and know sums of |c1, c2| between it and all available characters from first half after we do this precalculation. Also, precalculation is done trivially in O(2 ^ 12 * 12^2): fix mask, fix i and then iterate over 1 bits from mask and add double[c1][c2]. </p><p>Third subproblem is left, but it can be done similarly to second one. Instead of double[c1][c2], we’ll have triple[c1][c2][c3] = how many words contain all 3 characters c1, c2 and c3? We also do meet in the middle here, divide those 24 letters into 2 sets of 12 letters. We have 4 cases:</p><p>1/ c1, c2, c3 belong to first half</p><p>2/ c1, c2, c3 belong to second half</p><p>3/ c1, c2 belong to first half and c3 to second half</p><p>4/ c1 belongs to first half and c2, c3 to second half</p><p>1/ and 2/ are done brute force, like in second subproblem (the only difference is we choose 3 characters instead of 2, having complexity O(2 ^ 12 * 12 ^ 3)). For 3/ and 4/ we also precompute 2 matrixes: </p><p>mixed_two_one[mask][i] = c1 and c2 belong to mask from first half and c3 is i-th character from second half </p><p>and </p><p>mixed_one_two[mask][i] = c1 is i-th character from first half and c2, c3 belong to mask from second half. </p><p>Those can also be calculated in O(2 ^ 12 * 12^3).</p><p>So precalculation part is O(2 ^ 12 * 12 ^ 3) = 7077888 operations.</p><p>For calculate answering queries complexity, take all numbers from 0 to 2^24 — 1 and sum their bit count. This is a well known problem, the sum is 0 * C(24, 0) + 1 * C(24, 1) + ... + 24 * C(24, 24) = 201326592. In total we get 208404480 operations. C++ source makes them in 2 seconds. </p><p>Code: <a href=\"http://pastie.org/8651829\">http://pastie.org/8651829</a></p><h2>Solution fount by contestants</h2><p>Like in D1 D task, official solution was over complicated. This solution is more simple to understand, code and it's more elegant. If someone wants to complicate his life, (s)he can code also official solution :)</p><p>Let's start by assigning a bitmask to each word in following way: ith bit is 1 if and only if letter ('a' + i) appears in the current word. For example, for word acd, its bitmask is 2^0 + 2^2 + 2 ^ 3 = 13 and for word aab its bitmask is 2^0 + 2^1 = 3. After reading the words from dictionary, we store a matrix cnt[mask] = how many words from dictionary correspond to mask?</p><p>We iterate bitmasks from 0 to 2^24 — 1, this time corresponding to each possible question of Iahubina. Let's focus on a bitmask X. We need to get sum of cnt[mask], when mask and X share at least one common bit having value 1 (formally (X AND mask) > 0). In order to do this, we need a reduction which may be not so obvious. </p><p>What if instead of counting all words containing at least one of vowels {w1, w2, ..., wk} we count all words which don't contain ANY of vowels {w1, w2, ..., wk}? Suppose this number is ret. Then, all words containing at least one of vowels is N — ret. From all words, we erase those words which do not contain any vowels from set {w1, w2, ..., wk} (and which obviously are wrong words). Obviously, it's left only words containing at least one vowel, so good words. Now, for a word not to contain any of vowels {w1, w2, ..., wk} it needs to contains ONLY vowels from set {"a", "b", "c", ..., "x"} \\ {w1, w2, ..., wk} (set of allowed letters from which we erased vowels w1, w2, ..., wk}. </p><p>And this is reduction we needed. For a bitmask X we need to calculate sum of cnt[mask], where mask is a subset of X (we can set some bits from X from 1 to 0 in order to obtain mask). For a mask, let's keep this sum in res[mask]. We can calculate res array using divide and conquer.</p><p>Let's make a function solve(left, right), which completes array res in the way described above, if we consider only elements cnt[k] with left <= k < right (for simplicity, I'll consider elements which do not lie in this range to be equal to 0). Now we need to solve for a range [left, right]. Let's have in res1[] = solve(left, med) and in res2[] = solve(med, right), where med = (left + right) / 2. We need to put together res1[] and res2[] in order to obtain res[].</p><p>for (int i = left; i < med; ++i) res[i] = res1[i];</p><p>Numbers in [left, med] have most significant bit equal to 0. We can only keep it 0 and add what we calculated before. We can't add any element from res2[], because those elements have most significant bit equal to 1 and we're not allowed to change bit 0 into bit 1.</p><p>for (int i = med; i < right; ++i) res[i] = res1[i — med] + res2[i];</p><p>Here, most significant bit is 1. Adding res1[] corresponds to changing bit from 1 to 0, adding res2[] corresponds to leaving bit 1.</p><p>Of course, we need to threat the base case here, too. When left + 1 = right, res[left] = cnt[left]. We can keep only one array res[] instead of 3, I explained it this way only for simplicity. Also, there is no need for keeping separate arrays for res[] and cnt[], one can solve all task with only one array. In order to get res[], we simply call solve(0, 2^24).</p><p>Complexity of solution is O(2 ^ 24 * 24). I leave the proof homework, it's almost identical to complexity proof of D1 D "Author solution" (that with building a binary tree).</p><p>For a reference solution, check <a class=\"rated-user user-red\" href=\"/profile/Endagorion\" title=\"Grandmaster Endagorion\">Endagorion</a>'s AC source during contest. </p></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/384\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 225 (Div. 2)</a> </span>\r\n </div>\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/383\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 225 (Div. 1)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-12457-10531\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"12457\",\n blogEntryId: \"10476\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n <div style=\"font-size: 1.1rem;line-height: 11px;\">\r\n <img style=\"vertical-align: middle;\" src=\"//codeforces.org/s/81027/images/blog/tags.png\" title=\"Tags\" alt=\"Tags\"/>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=codeforces\" class=\"tag notice\" style=\"text-decoration: none;\">codeforces</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=225\" class=\"tag notice\" style=\"text-decoration: none;\">225</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=editorial\" class=\"tag notice\" style=\"text-decoration: none;\">editorial</a>\r\n </span>\r\n </div>\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-10531\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+418</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-10531\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/fchirica\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/fchirica\">\n fchirica\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Jan/20/2014 22:18\">10 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/10476#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/10476#comments\">\n 52\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"10547\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (45)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158582\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PAP\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/78534/avatar/d5bcc04085999f83.jpg'/> </a>\n <div><a href=\"/profile/PAP\" title=\"Candidate Master PAP\" class=\"rated-user user-violet\">PAP</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 22:40\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158582\" href=\"?#comment-158582\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158582\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"32\"\r\n data-commentUserId=\"78534\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+32</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158582\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>perfect editorial! thanks a lot!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158582 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158582 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158582\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158591\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/eduardische\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2320/avatar/3ac70493aa90ad2e.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/eduardische\" title=\"International Master eduardische\" class=\"rated-user user-orange\">eduardische</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 22:48\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158591\" href=\"?#comment-158591\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"158591\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"158591\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"10\"\r\n data-commentUserId=\"2320\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+10</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158591\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Just would like to report a typo in 383D contestants' solution: the formula computes D[i+1][j] and not D[i][j]. Thanks for the quick editorial!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158591 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158591 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158591\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158596\" commentParentId=\"158591\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/fchirica\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/57267/avatar/4e655c69b8ad66c2.jpg'/> </a>\n <div><a href=\"/profile/fchirica\" title=\"Candidate Master fchirica\" class=\"rated-user user-violet\">fchirica</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 22:52\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158596\" href=\"?#comment-158596\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-158591\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158596\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"15\"\r\n data-commentUserId=\"57267\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+15</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158596\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks. Fixed. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158596 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158596 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158596\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158598\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Mikester\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/109566/avatar/401b6d72d8f2e768.jpg'/> </a>\n <div><a href=\"/profile/Mikester\" title=\"Master Mikester\" class=\"rated-user user-orange\">Mikester</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 22:54\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158598\" href=\"?#comment-158598\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158598\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"13\"\r\n data-commentUserId=\"109566\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+13</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158598\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>elfus has some of the best rounds on Codeforces, and definitely the best editorials. Congratulations to you and Rares for the round !</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158598 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158598 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158598\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158599\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/iPs\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/144469/avatar/10358ae72910ceac.jpg'/> </a>\n <div><a href=\"/profile/iPs\" title=\"Expert iPs\" class=\"rated-user user-blue\">iPs</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 22:54\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158599\" href=\"?#comment-158599\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158599\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"33\"\r\n data-commentUserId=\"144469\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+33</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158599\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>best editorial I have ever seen in codeforces</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158599 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158599 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158599\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158600\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/bli0042\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/88584/avatar/51c3a9b55a3537fa.jpg'/> </a>\n <div><a href=\"/profile/bli0042\" title=\"Candidate Master bli0042\" class=\"rated-user user-violet\">bli0042</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 22:54\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158600\" href=\"?#comment-158600\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"158600\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"158600\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"88584\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158600\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For Div 2C, if A[i] = A[j] = 0 and we put i before j, won't j lose milk? Or am I misinterpreting the solution?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158600 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158600 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158600\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158601\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/aabs08\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/aabs08\" title=\"Expert aabs08\" class=\"rated-user user-blue\">aabs08</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 22:55\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158601\" href=\"?#comment-158601\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"158601\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"158601\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"9\"\r\n data-commentUserId=\"86699\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+9</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158601\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>One of the best editorials i came across in codeforces :D otherwise the editorial here are really very short and objective.</p><p>Every one here should write editorials like you :) !!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158601 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158601 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158601\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158607\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Xellos\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/69675/avatar/8526bcfc8e687b43.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/Xellos\" title=\"International Grandmaster Xellos\" class=\"rated-user user-red\">Xellos</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 23:03\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158607\" href=\"?#comment-158607\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"158607\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"158607\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"17\"\r\n data-commentUserId=\"69675\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+17</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158607\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Finally a tutorial worth upvoting!</p><p>I didn't really need to think about D. As soon as I saw the constraint on <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/986936bec272878d92f9c6fb0f0ce3c5b118cc0e.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />, I decided to try a DP on (position,sum) — it was a massive hint for me. Well, sometimes it just happens that there's a simple solution, which the author doesn't realize :D. Maybe this could be eliminated by some extensive "problem testing" by random capable people?</p><p>I guess I was also lucky in not trying to solve B. I solved in the order: A (because it's easy), C (because I like it), D (because it's easy) :D</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158607 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158607 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158607\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158610\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Mostafa_36a2\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/137637/avatar/28a01293a2b409.jpg'/> </a>\n <div><a href=\"/profile/Mostafa_36a2\" title=\"Specialist Mostafa_36a2\" class=\"rated-user user-cyan\">Mostafa_36a2</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 23:09\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158610\" href=\"?#comment-158610\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158610\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"-9\"\r\n data-commentUserId=\"137637\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-9</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158610\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I've found a very short solution for Div2 C , by zxz5759209</p> <pre><code>scanf("%d",&n);\n LL cnt=0,sum=0;\n for(int i=1;i<=n;i++)\n {\n scanf("%d",&x);\n cnt+=(LL)x;\n if(!x)sum+=cnt;\n }\n printf("%I64d\\n",sum);\n</code></pre></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158610 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158610 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158610\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158641\" commentParentId=\"158610\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Robert.One\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Robert.One\" title=\"Pupil Robert.One\" class=\"rated-user user-green\">Robert.One</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 01:27\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158641\" href=\"?#comment-158641\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-158610\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158641\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"150202\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158641\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I also had this solution and i got accepted but it took 1 hour to find it during the contest</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158641 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158641 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158641\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158612\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Darek_\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Darek_\" title=\"Specialist Darek_\" class=\"rated-user user-cyan\">Darek_</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 23:12\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158612\" href=\"?#comment-158612\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158612\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"152123\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158612\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks for an informative editorial.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158612 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158612 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158612\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158618\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Mostafa_36a2\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/137637/avatar/28a01293a2b409.jpg'/> </a>\n <div><a href=\"/profile/Mostafa_36a2\" title=\"Specialist Mostafa_36a2\" class=\"rated-user user-cyan\">Mostafa_36a2</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 23:25\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158618\" href=\"?#comment-158618\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"158618\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"158618\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"137637\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158618\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Unbelivable solution for Div2,B by Sick_Coder</p> <pre><code>cin >> n >> m >> k;\n cout << m * (m - 1) / 2 << "\\n";\n\n for (1, m, i)\n \tfor (i + 1, m, j)\n \t\tif (!k)\n \t\t\tcout << i << " " << j << "\\n";\n \t\telse\t\n \t\t\tcout << j << " " << i << "\\n";\n</code></pre></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158618 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158618 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158618\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158631\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mugurelionut\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/63702/avatar/45e4d5390c215090.jpg'/> </a>\n <div><a href=\"/profile/mugurelionut\" title=\"International Master mugurelionut\" class=\"rated-user user-orange\">mugurelionut</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 23:57\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158631\" href=\"?#comment-158631\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158631\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"63702\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158631\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>A very good editorial, indeed! (but please don't forget about Div1E) And the problems were really nice. But I think problem B was tougher than it should have been for its amount of points. I've read some comments saying that problem B had too weak pretests (because so many solutions failed the final system tests). I would have to say that my experience with problem B was the exact opposite. I coded two wrong solutions (which failed some pretest or another) before eventually finding and implementing the right solution. So I'd say that problem B had good pretests :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158631 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158631 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158631\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158635\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/MohammadFatafta\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/148405/avatar/4276577919b9713d.jpg'/> </a>\n <div><a href=\"/profile/MohammadFatafta\" title=\"Specialist MohammadFatafta\" class=\"rated-user user-cyan\">MohammadFatafta</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 00:11\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158635\" href=\"?#comment-158635\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158635\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"148405\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158635\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>now this is a real editorial!! thanks guys :D</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158635 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158635 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158635\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158636\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/matrix\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/matrix\" title=\"Master matrix\" class=\"rated-user user-orange\">matrix</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 00:15\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158636\" href=\"?#comment-158636\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"158636\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"158636\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"16572\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158636\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Hi,</p><p>Great and fast editorial with complete details. </p><p>Thanks very much.</p><p>Edit: I think there is a small typo: "It’s not hard to see that answer for a fixed (i1, j1) is left[i1][j1] * value[2 * j1 – sum_of_elements_from_i1]." I guess you meant count[2 * j1 – sum_of_elements_from_i1].</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158636 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158636 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158636\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158637\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Kyuubi\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/83590/avatar/b87432a652bb276.jpg'/> </a>\n <div><a href=\"/profile/Kyuubi\" title=\"Expert Kyuubi\" class=\"rated-user user-blue\">Kyuubi</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 00:18\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158637\" href=\"?#comment-158637\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158637\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"2\"\r\n data-commentUserId=\"83590\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+2</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158637\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Best Editorials I have seen on codeforces yet! :D</p><p>For Propagating tree, how do we keep track of alternating levels in the arrays we created using DFS ? </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158637 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158637 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158637\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158640\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/k_____k\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/60285/avatar/422359e1ae9d666c.jpg'/> </a>\n <div><a href=\"/profile/k_____k\" title=\"Expert k_____k\" class=\"rated-user user-blue\">k_____k</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 01:07\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158640\" href=\"?#comment-158640\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158640\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"2\"\r\n data-commentUserId=\"60285\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+2</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158640\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Best Editorials Ever ! #thanks to the authors, for posting alternative solutions of contestants also. Great start in 2014. #Looking Forward.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158640 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158640 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158640\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158658\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/sillycross\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/41652/avatar/58966d0c793c6394.jpg'/> </a>\n <div><a href=\"/profile/sillycross\" title=\"Grandmaster sillycross\" class=\"rated-user user-red\">sillycross</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 07:49\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158658\" href=\"?#comment-158658\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158658\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"9\"\r\n data-commentUserId=\"41652\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+9</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158658\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Div1 E can be solved in O(2^24*24) or O(2^24+2^12*n)..</p><p>O(2^24*24): dp[i][s] means the sum of all contributions of subset s where all digits are same as s except the last i digits.. </p><p>O(2^24+2^12*n): the length of word is only 3. We divide the 24 letters in half, calculate the answer for all first 12 letters and all last 12 letters and merge them with brute-force. This can be solved in O(2^24). Then we subtract the words that are counted twice: these words are words that have 2 letters in first half and 1 in second half, or 2 in second half and 1 in first half. Let's consider the first case: for each subset of first 12 letters we check each word whether it has exactly 2 letters in this half, if so, we can say all masks in another half that contains the third letter need to be subtracted by 1. This can be solved in 2^12*(2^12+n). Same algorithm can be used to solve the second case. Although this algorithm runs slower than O(2^24*24) bcuz of its larger constant... </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158658 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158658 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158658\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158663\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/VeniVidiVici\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/VeniVidiVici\" title=\"Candidate Master VeniVidiVici\" class=\"rated-user user-violet\">VeniVidiVici</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 09:39\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158663\" href=\"?#comment-158663\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158663\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"149163\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158663\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Very nice editorial! Disappointed in Div 2B though, really expected the "real" problem rather than just insertion sort but that's what you get for not reading carefully ;)</p><p>However, does anyone have an accepted solution that is "real" (e.g. finds the minimum number of operations necessary and prints such a solution)? I was close but my computer died during contest and I haven't tried so much since (of course you can do O((mn)^2) easily but this is way too slow, there should be a O(n*m^2) solution but again my computer was unable to operate). My approach was to make 2-D boolean array to check if a swap is necessary, but I'm not sure if order of operations will end up being a big problem.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158663 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158663 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158663\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158685\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/LegendaryGrandmaster\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/142091/avatar/a3a5a4b5c26ac419.jpg'/> </a>\n <div><a href=\"/profile/LegendaryGrandmaster\" title=\"Specialist LegendaryGrandmaster\" class=\"rated-user user-cyan\">LegendaryGrandmaster</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 14:34\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158685\" href=\"?#comment-158685\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158685\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"142091\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158685\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>One of the best codeforces editorials ever! Thanks!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158685 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158685 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158685\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158687\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/BENYAM1N\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/84938/avatar/d2ae2657d8898e38.jpg'/> </a>\n <div><a href=\"/profile/BENYAM1N\" title=\"Master BENYAM1N\" class=\"rated-user user-orange\">BENYAM1N</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 15:24\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158687\" href=\"?#comment-158687\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"158687\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"158687\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"84938\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158687\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks a lot. very good contest and good editorial too!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158687 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158687 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158687\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158689\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/JuanMata\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/82548/avatar/a7d69af7b441c6d7.jpg'/> </a>\n <div><a href=\"/profile/JuanMata\" title=\"Expert JuanMata\" class=\"rated-user user-blue\">JuanMata</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 15:47\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158689\" href=\"?#comment-158689\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158689\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"82548\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158689\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>this is one of the best editorials on CF ever!!!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158689 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158689 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158689\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158700\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Vicfred\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/76941/avatar/d067b7433ec39337.jpg'/> </a>\n <div><a href=\"/profile/Vicfred\" title=\"Pupil Vicfred\" class=\"rated-user user-green\">Vicfred</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 16:25\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158700\" href=\"?#comment-158700\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158700\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"11\"\r\n data-commentUserId=\"76941\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+11</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158700\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>The best editorial I've read in a while here, thanks.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158700 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158700 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158700\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158727\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/beecoder\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/beecoder\" title=\"Pupil beecoder\" class=\"rated-user user-green\">beecoder</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 21:13\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158727\" href=\"?#comment-158727\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158727\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"89551\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158727\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Hi, The way I print answers for 'Coder Problem' is as follows. This takes 124 ms. is there a way to print the answers faster ? </p> <pre><code> \tfor (int i = 0 ; i < number ; i ++ ) { \n \t\tfor (int k = 0 ; k < number ; k ++ ) { \n \t\t\tif (flag) {\n \t\t\t\tif ( k % 2 == 1) out.print('.');\n \t\t\t\tif( k% 2 == 0 ) out.print('C');\n \t\t\t} else {\n \t\t\tif ( k % 2 == 1) out.print('C');\n \t\t\tif( k% 2 == 0 ) out.print('.');\t\n \t\t\t}\n \t\t}\n \t\tif (flag) flag = false;\n \t\telse flag = true;\n \t\tout.print("\\n");\n \t}\n \n</code></pre></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158727 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158727 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158727\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158742\" commentParentId=\"158727\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Mostafa_36a2\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/137637/avatar/28a01293a2b409.jpg'/> </a>\n <div><a href=\"/profile/Mostafa_36a2\" title=\"Specialist Mostafa_36a2\" class=\"rated-user user-cyan\">Mostafa_36a2</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/22/2014 14:00\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158742\" href=\"?#comment-158742\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-158727\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158742\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"137637\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158742\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>As the line contains k characters , and every odd lines are identical , also the even ones,</p><p>you can build 2 strings [C.C.C.C] and [.C.C.C.] and print them alternately </p><p>[In my opinion Java is slow language any way ]</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158742 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158742 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158742\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158752\" commentParentId=\"158727\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/t_thirupathi\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/146179/avatar/98c28348196ce4ca.jpg'/> </a>\n <div><a href=\"/profile/t_thirupathi\" title=\"Specialist t_thirupathi\" class=\"rated-user user-cyan\">t_thirupathi</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/22/2014 18:19\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158752\" href=\"?#comment-158752\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-158727\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158752\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"146179\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158752\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Modulo operations are time consuming.</p><p>To check if a number <code>n</code> is odd, you could use <code>if (n & 1)</code></p> <pre><code>for (int i = 0; i < n; i++) {\n for (int j = 0; j < n; j++)\n if ((i + j) & 1)\n out.print('.');\n else \n out.print('C');\n out.print('\\n');\n}\n</code></pre></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158752 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158752 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158752\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158745\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/JuanMata\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/82548/avatar/a7d69af7b441c6d7.jpg'/> </a>\n <div><a href=\"/profile/JuanMata\" title=\"Expert JuanMata\" class=\"rated-user user-blue\">JuanMata</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/22/2014 14:49\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158745\" href=\"?#comment-158745\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"158745\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"158745\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"82548\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158745\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>i think there is a small bug in the <a href=\"http://pastie.org/8651824\">pastie link</a> u posted for the solution of Div1 C problem.</p><p>i submitted almost exact copy of it (<a href=\"/contest/383/submission/5769615\" title=\"Submission 5769615 by JuanMata\">5769615</a>), but got WA#6. then i found the bug, corrected it and resubmitted (<a href=\"/contest/383/submission/5769890\" title=\"Submission 5769890 by JuanMata\">5769890</a>) and got AC.</p><p>referring to my two submissions, corrections in line <strong>68</strong> (last statement of <strong>dfs</strong>) and line <strong>109</strong> (the second call to <strong>update</strong>).</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158745 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158745 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158745\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"615836\" commentParentId=\"158745\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/adityakr007\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/adityakr007\" title=\"Expert adityakr007\" class=\"rated-user user-blue\">adityakr007</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/05/2020 18:54\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-615836\" href=\"?#comment-615836\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-158745\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"615836\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"866209\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-615836\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can you explain what exactly have you done in your submission (<a href=\"/contest/383/submission/5769890\" title=\"Submission 5769890 by JuanMata\">5769890</a>) for this problem?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-615836 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-615836 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-615836\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"629531\" commentParentId=\"615836\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/JuanMata\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/82548/avatar/a7d69af7b441c6d7.jpg'/> </a>\n <div><a href=\"/profile/JuanMata\" title=\"Expert JuanMata\" class=\"rated-user user-blue\">JuanMata</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/25/2020 18:14\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-629531\" href=\"?#comment-629531\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-615836\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"629531\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"82548\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-629531\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>sorry bro i've forgotten ... that was over 6yrs ago now!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-629531 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-629531 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-629531\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158751\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/TempuX\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/30820/avatar/c50adc243ea4e2fa.jpg'/> </a>\n <div><a href=\"/profile/TempuX\" title=\"Specialist TempuX\" class=\"rated-user user-cyan\">TempuX</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/22/2014 17:07\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158751\" href=\"?#comment-158751\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158751\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"30820\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158751\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Hi, I tried to implement the Volcano problem in the way explained in the editorial but I'm getting TLE. Here is my code <a href=\"//codeforces.com/contest/384/submission/5770818\">submission</a> What am I doing wrong ? Thanks anyway.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158751 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158751 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158751\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158811\" commentParentId=\"158751\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/TempuX\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/30820/avatar/c50adc243ea4e2fa.jpg'/> </a>\n <div><a href=\"/profile/TempuX\" title=\"Specialist TempuX\" class=\"rated-user user-cyan\">TempuX</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/23/2014 17:29\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158811\" href=\"?#comment-158811\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-158751\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158811\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"30820\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158811\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Turns out my binary search is causing the problem and I don't see what is wrong with it... I would appreciate any ideas.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158811 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158811 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158811\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159025\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/bboy_drain\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/76710/avatar/e0feb3aa135911d4.jpg'/> </a>\n <div><a href=\"/profile/bboy_drain\" title=\"Expert bboy_drain\" class=\"rated-user user-blue\">bboy_drain</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/25/2014 01:34\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159025\" href=\"?#comment-159025\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159025\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"76710\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159025\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Wow! This really helped me a lot! Very detailed explanations!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159025 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159025 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159025\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159092\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/AlexandruValeanu\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/131651/avatar/1c7d989c45052941.jpg'/> </a>\n <div><a href=\"/profile/AlexandruValeanu\" title=\"Candidate Master AlexandruValeanu\" class=\"rated-user user-violet\">AlexandruValeanu</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/25/2014 21:27\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159092\" href=\"?#comment-159092\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159092\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"131651\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159092\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>It was by far your best round on Codeforces, <a class=\"rated-user user-blue\" href=\"/profile/fchirica\" title=\"Expert fchirica\">fchirica</a>. The problems were great, very different one from the other and some of them didn't require any algorithmic skills at all. Good job!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159092 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159092 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159092\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159261\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lawsonh\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/lawsonh\" title=\"Expert lawsonh\" class=\"rated-user user-blue\">lawsonh</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/28/2014 06:33\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159261\" href=\"?#comment-159261\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"159261\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"159261\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"55047\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159261\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>for div1 383C should end[5] = 7? edit: nvm drew the tree wrong</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159261 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159261 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159261\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159474\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/tiagonapoli\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/150060/avatar/6615fcab66b23361.jpg'/> </a>\n <div><a href=\"/profile/tiagonapoli\" title=\"Candidate Master tiagonapoli\" class=\"rated-user user-violet\">tiagonapoli</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/30/2014 22:28\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159474\" href=\"?#comment-159474\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159474\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"150060\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159474\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Great Editorial! Thanks so much, i've learned a lot!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159474 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159474 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159474\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159707\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lchf\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/60496/avatar/e9939e755252ec16.jpg'/> </a>\n <div><a href=\"/profile/lchf\" title=\"Candidate Master lchf\" class=\"rated-user user-violet\">lchf</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/02/2014 17:28\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159707\" href=\"?#comment-159707\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159707\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"60496\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159707\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Amazing solution by Endagorion.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159707 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159707 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159707\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"177400\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/sourabh912\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/57335/avatar/bf83b9340e3cbb17.jpg'/> </a>\n <div><a href=\"/profile/sourabh912\" title=\"Specialist sourabh912\" class=\"rated-user user-cyan\">sourabh912</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/12/2014 20:39\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-177400\" href=\"?#comment-177400\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"177400\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"57335\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-177400\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In Div 1C problem, I could not understand how it can be solved using single fenwick tree from the solution link in the editorial. Can anyone please help.</p><p>Thanks</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-177400 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-177400 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-177400\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"291157\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/l_Love_KFC\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/258117/avatar/bbaec3ce1613f5bd.jpg'/> </a>\n <div><a href=\"/profile/l_Love_KFC\" title=\"Expert l_Love_KFC\" class=\"rated-user user-blue\">l_Love_KFC</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Apr/29/2016 08:23\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-291157\" href=\"?#comment-291157\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"291157\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"258117\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-291157\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In Div.1 A I didn't catch the point that in 1st, quote : "If we put i before j, no additional cost will be added. Since j is in right of i and i only adds cost when it finds elements in left of i, j won’t be affected when processing i." Won't we lose milk if we put firstly i, in case of that j sees that and loses milk? Or am I misunderstanding the task? </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-291157 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-291157 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-291157\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"309434\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/haleyk100198\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/416324/avatar/f2d97d505af17e9d.jpg'/> </a>\n <div><a href=\"/profile/haleyk100198\" title=\"Candidate Master haleyk100198\" class=\"rated-user user-violet\">haleyk100198</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/11/2016 06:32\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-309434\" href=\"?#comment-309434\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"309434\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"416324\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-309434\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I wonder how the problem Div1C can be converted to a segment tree lazy propagation implementation question, for trees like (1-2 2-3 3-4 4-5 .... 9999-E4) how can we achieve O(log N) update time?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-309434 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-309434 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-309434\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"310847\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/my_new_handle\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/233736/avatar/24128c61b65e3262.jpg'/> </a>\n <div><a href=\"/profile/my_new_handle\" title=\"Candidate Master my_new_handle\" class=\"rated-user user-violet\">my_new_handle</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/20/2016 14:49\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-310847\" href=\"?#comment-310847\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"310847\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"233736\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-310847\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>а зачем в таске б массив он влияет как-то?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-310847 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-310847 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-310847\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"332763\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/rhezo\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/305605/avatar/aa59e9c2ec688c6a.jpg'/> </a>\n <div><a href=\"/profile/rhezo\" title=\"Candidate Master rhezo\" class=\"rated-user user-violet\">rhezo</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Dec/24/2016 07:56\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-332763\" href=\"?#comment-332763\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"332763\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"305605\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-332763\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I'm getting Runtime Error on test 44 in <a href=\"//codeforces.com/problemset/problem/383/C\">Propogating Tree</a>. </p><p>This is because of stack overflow right? That test has N = 2e5 and for a straight chain of nodes, I'll get a runtime error with a recursive DFS right? What to do in such cases? </p><p>I can write an iterative DFS, but I do HLD recursively too and I'm not quite sure if I can write an iterative HLD. </p><p>Can anyone tell me what to do in such cases? I'm assuming that I got the runtime error due to stackoverflow from DFS.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-332763 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-332763 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-332763\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"346070\" commentParentId=\"332763\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/yinanzhu\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/520731/avatar/d61a58bf5df54146.jpg'/> </a>\n <div><a href=\"/profile/yinanzhu\" title=\"Expert yinanzhu\" class=\"rated-user user-blue\">yinanzhu</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/26/2017 07:18\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-346070\" href=\"?#comment-346070\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-332763\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"346070\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"520731\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-346070\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I used recursive dfs and passed all test case. Test 44 cost 1.5 s</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-346070 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-346070 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-346070\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"387028\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/blue__legend\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/blue__legend\" title=\"Expert blue__legend\" class=\"rated-user user-blue\">blue__legend</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/23/2017 07:16\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-387028\" href=\"?#comment-387028\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"387028\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"284949\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-387028\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>How to solve DIV 1 C using one fenwick or segment tree. The code link given in editorial is not working.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-387028 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-387028 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-387028\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"757423\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Ausmosian\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Ausmosian\" title=\"Expert Ausmosian\" class=\"rated-user user-blue\">Ausmosian</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/05/2021 15:05\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-757423\" href=\"?#comment-757423\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"757423\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"727283\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-757423\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>[<a href=\"https://codeforces.com/contest/383/problem/C\">384E — Propagating tree</a>] Can also be solved using Square Root Decomposition. <a href=\"https://codeforces.com/contest/383/submission/106526543\">Submission</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-757423 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-757423 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-757423\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"838255\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/3hill\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1621900/avatar/478297db63bad207.jpg'/> </a>\n <div><a href=\"/profile/3hill\" title=\"Expert 3hill\" class=\"rated-user user-blue\">3hill</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/11/2021 17:02\">2 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-838255\" href=\"?#comment-838255\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"838255\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1621900\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-838255\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I am Getting MLE on TC-53<br />Can someone review my code and figure out the issue ,Thanks</p> <ul> <li><a href=\"https://codeforces.com/contest/383/problem/C\">Problem</a></li> <li><a href=\"https://codeforces.com/contest/383/submission/128510633\">My code</a></li> </ul></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-838255 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-838255 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-838255\">\r\n </ul>\r\n</div>\r\n <br/>\r\n\r\n<div id=\"editBox-10547\" style=\"width:50em;display:none;\">\r\n <div class=\"previewBody\" style=\"border: 1px solid #d4d4d4; margin-bottom: 0.5em; padding: 0.25em; display:none;\"> </div>\r\n <div style=\"width: 1px\"> </div>\r\n <div class=\"commentLocale\" style=\"position: relative; top: 0.5em;left:4px;display: none;\">\r\n <input type=\"radio\" name=\"locale\" value=\"en\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In English</span>\r\n <input style=\"margin-left:1em\" type=\"radio\" name=\"locale\" value=\"ru\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In Russian</span>\r\n </div>\r\n <textarea data-drafts-id=\"CommentReplyFrame\" class=\"wysiwyg\" name=\"editContent\" rows=\"20\" style=\"width:99%;\"></textarea>\r\n <div class=\"error error__content\"></div>\r\n <div style=\"text-align:center;\">\r\n <input type=\"button\" name=\"preview\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Preview\"/>\r\n <input type=\"button\" name=\"save\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Save\"/>\r\n </div>\r\n</div>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n\r\nvar firstPreview10547 = true;\r\nvar lastPreviewContent10547 = '';\r\n\r\nif (!window.moveCommentRevision) {\r\n moveCommentRevision = function(e, dir) {\r\n var p = e.parent();\r\n var revisionCount = parseInt(p.attr(\"revisionCount\"));\r\n var revision = parseInt(p.attr(\"revision\"));\r\n var next = revision + dir;\r\n var commentId = p.attr(\"commentId\");\r\n if (next >= 1 && next <= revisionCount) {\r\n $.post(\r\n \"/data/comment-data\",\r\n {action: \"revision\", commentId: commentId, revision: next},\r\n function(json) {\r\n if (json.success == \"true\") {\r\n var parentDiv = e;\r\n\r\n while (parentDiv !== null && (parentDiv[0].nodeName.toLowerCase() !== \"td\" || !parentDiv.hasClass(\"right\"))) {\r\n parentDiv = parentDiv.parent();\r\n }\r\n\r\n if (parentDiv === null) {\r\n return;\r\n }\r\n\r\n parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\").html(json.content);\r\n Codeforces.setupSpoilers(parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\"));\r\n p.attr(\"revision\", next);\r\n p.find(\"span.revision\").text(next);\r\n if (next == 1) {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"visible\");\r\n }\r\n if (next == revisionCount) {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"visible\");\r\n }\r\n\r\n window.updateTypography();\r\n MathJax.Hub.Typeset();\r\n } else {\r\n alert(e.error);\r\n }\r\n },\r\n \"json\"\r\n );\r\n }\r\n };\r\n}\r\n\r\n$(\"div[commentableId=10547] a.leftRevision\").click(function () {\r\n window.moveCommentRevision($(this), -1);\r\n return false;\r\n});\r\n\r\n$(\"div[commentableId=10547] a.rightRevision\").click(function () {\r\n window.moveCommentRevision($(this), +1);\r\n return false;\r\n});\r\n\r\n\r\n\r\n });\n </script>\n\r\n\r\n <script src=\"//codeforces.org/s/81027/js/swfobject-2.2.min.js\" type=\"text/javascript\"></script>\n <script src=\"//codeforces.org/s/81027/js/ftaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n if (window.evercookie) {\n var ec = new evercookie({\n history: false,\n silverlight: false,\n baseurl: '',\n asseturi: '/assets',\n phpuri: '/2fdcd78',\n pngPath: '/eps',\n etagPath: '/ees',\n cachePath: '/ecs'\n });\n\n var randomNumber = function () {\n return Math.random().toString(36).substr(2);\n };\n\n var randomToken = function () {\n return (randomNumber() + randomNumber()).substring(0, 18);\n };\n\n window._ftaa = \"\";\n\n ec.get(\"70a7c28f3de\", function (value) {\n window._ftaa = value;\n if (!window._ftaa) {\n window._ftaa = randomToken();\n ec.set(\"70a7c28f3de\", window._ftaa);\n }\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n } else {\n window._ftaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\n <script src=\"//codeforces.org/s/81027/js/bfaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n var fpCallback = function() {\n Fingerprint2.get({}, function(components) {\n window._bfaa = Fingerprint2.x64hash128(components.map(function (pair) { return pair.value }).join(), 31);\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n };\n if (typeof Fingerprint2 !== 'undefined') {\n if (window.requestIdleCallback) {\n requestIdleCallback(fpCallback)\n } else {\n setTimeout(fpCallback, 500)\n }\n } else {\n window._bfaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"a.new-root-comment\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n\r\n $(\".comment-table .reply a\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".vote-for-comment\").mouseover(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").mouseout(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").click(function () {\r\n var vote = $(this);\r\n var commentId = $(this).parent().attr(\"commentid\");\r\n var commentRating = $(this).parent().attr(\"data-commentRating\");\r\n var direction = $(this).attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n $.post(\"/data/comment/vote\", {commentId: commentId, _tta: Codeforces.tta(), vote: direction, commentRating: commentRating}, function(data) {\r\n if (direction != 0 && !ownComment && data[\"success\"] == \"true\") {\r\n vote.parent().find(\".vote-for-comment\").attr(\"voteDirection\", 0);\r\n if (direction == 1)\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n else {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.closest(\".CommentVoteFrame\").find(\".ComplaintFrame\").css(\"display\", \"inline-block\");\r\n }\r\n vote.find(\"img\").attr(\"popacity\", \"1.0\");\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n vote.parent().find(\".commentRating\").html(data[\"commentRating\"]);\r\n }\r\n Codeforces.showMessage(data[\"message\"]);\r\n }, \"json\");\r\n return false;\r\n });\r\n\r\n $(\".negative-comment-vote\").closest(\".comment-table\").addClass(\"comment-bad\");\r\n\r\n $(\".troll-comment-vote\").closest(\".comment\").css(\"display\", \"none\");\r\n\r\n $(\".too-negative-comment-vote\").closest(\".comment-table\").each(function () {\r\n var e = $(this);\r\n e.addClass(\"comment-too-bad\");\r\n var commentId = e.attr(\"commentId\");\r\n $(\"<div class='bad-comment-replacement ttypography'>The comment is hidden because of too negative feedback, click <a href=# class=show-bad-comment-link>here</a> to view it</div>\").appendTo(\r\n e.find(\".right\")\r\n );\r\n e.find(\".comment-content\").hide();\r\n e.find(\".show-bad-comment-link\").click(function () {\r\n e.find(\".comment-content\").show();\r\n e.find(\".bad-comment-replacement\").hide();\r\n return false;\r\n });\r\n });\r\n });\n </script>\n </div>\r\n\r\n <style type=\"text/css\">\r\n .new-comments-box {\r\n padding: 0.5em;\r\n width: 22px;\r\n font-size: 1.3rem;\r\n font-weight: bold !important;\r\n\r\n position: fixed;\r\n top: 40%;\r\n right: 0;\r\n opacity: 0.2;\r\n color: white;\r\n text-align: center;\r\n\r\n border: 1px solid #222;\r\n background-color: #888 !important;\r\n border-radius: 3px;\r\n -moz-border-radius: 3px;\r\n -webkit-border-radius: 3px;\r\n }\r\n\r\n .new-comments-box:hover {\r\n opacity: 1;\r\n }\r\n\r\n .new-comments-box .dir:hover {\r\n background: #3B5998 !important;\r\n cursor: pointer;\r\n }\r\n </style>\r\n\r\n <div class=\"new-comments-box\" data-position=\"outside\" data-index=\"-1\" style=\"display: none;\">\r\n <div class=\"up dir\" title=\"Ctrl+Up\">↑<hr/>\r\n </div>\r\n <div class=\"info\" title=\"New comments\"></div>\r\n <div class=\"down dir\" title=\"Ctrl+Down\">\r\n <hr/>↓\r\n </div>\r\n </div>\r\n\r\n <script>\r\n $(\".show-archived-checkbox\").change(function () {\r\n const checked = $(this).is(\":checked\");\r\n $.post(\"/data/comment-data\", {action: \"setShowArchived\", checked}, function (json) {\r\n if (json[\"success\"] !== \"true\") {\r\n alert(json[\"error\"]);\r\n } else {\r\n if (checked) {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are now displayed\")\r\n } else {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are no longer displayed\")\r\n }\r\n }\r\n });\r\n return false;\r\n });\r\n\r\n function gotoComment(direction) {\r\n var box = $(\".new-comments-box\");\r\n var index = parseInt(box.attr(\"data-index\"));\r\n if (index == -1)\r\n index = 0;\r\n else\r\n index = Math.max(0, Math.min(parseInt(box.find(\".info\").text()) - 1, index + direction));\r\n box.attr(\"data-index\", index);\r\n var comment = $($(\".comment .highlight-blue[commentId]\").get(index));\r\n $('html, body').animate({\r\n 'scrollTop': Math.max(0, comment.offset().top - ($(window).height() - comment.height()) / 2)\r\n });\r\n return false;\r\n }\r\n\r\n $(\".new-comments-box .down\").click(function () {\r\n return gotoComment(1);\r\n });\r\n\r\n $(\".new-comments-box .up\").click(function () {\r\n return gotoComment(-1);\r\n });\r\n\r\n $(document).keydown(function (e) {\r\n var code = (e.keyCode ? e.keyCode : e.which);\r\n if (e.ctrlKey) {\r\n if (code == 38 || code == 40) {\r\n gotoComment(code - 39);\r\n }\r\n }\r\n });\r\n\r\n var newCommentCount = $(\".comment .highlight-blue[commentId]\").length;\r\n if (newCommentCount > 0) {\r\n $(\".new-comments-box .info\").text(newCommentCount);\r\n $(\".new-comments-box\").show();\r\n }\r\n\r\n $('table.comment-table').mouseenter(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").addClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n\r\n $('table.comment-table').mouseleave(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").removeClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n </script>\r\n\r\n\r\n\r\n <script>\r\n function adjustTopicComplainFrames() {\r\n let topicIds = [];\r\n\r\n $(\".has-topic-id\").each(function () {\r\n const $this = $(this);\r\n const topicId = $this.attr(\"topicId\");\r\n if (topicId) {\r\n topicIds.push(topicId);\r\n }\r\n });\r\n\r\n $.post(\"/data/topics\", {\r\n action: \"findComplainableTopicIds\",\r\n topicIds: topicIds.join(\",\")\r\n }, function (json) {\r\n if (json[\"success\"] === \"true\") {\r\n for (const topicId of json[\"complainableTopicIds\"].split(\",\")) {\r\n $(\".has-topic-id[topicId=\" + topicId + \"]\").each(function () {\r\n $(this).find(\".meta .ComplaintFrame\").css(\"display\", \"inline-block\");\r\n });\r\n }\r\n }\r\n }, \"json\");\r\n }\r\n\r\n $(function () {\r\n adjustTopicComplainFrames();\r\n })\r\n </script>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-10531\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 10531, _tta: Codeforces.tta(), topicRevisionId: 36233, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-10531\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 10531, _tta: Codeforces.tta(), topicRevisionId: 36233, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n </div>\r\n </div>\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 22:13:02</span> (h1).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/81027/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/81027/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/81027/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/81027/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-81027.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'81287584a8369d92',t:'MTY5NjcwNTk4Mi42NDcwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"}}},{"rowIdx":1936,"cells":{"problem_id":{"kind":"string","value":"383C"},"contest":{"kind":"string","value":"383"},"problem":{"kind":"string","value":"C"},"lang":{"kind":"string","value":"en"},"problem_title":{"kind":"string","value":"C. Propagating tree"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">C. Propagating tree</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Iahub likes trees very much. Recently he discovered an interesting tree named propagating tree. The tree consists of <span class=\"tex-span\"><i>n</i></span> nodes numbered from <span class=\"tex-span\">1</span> to <span class=\"tex-span\"><i>n</i></span>, each node <span class=\"tex-span\"><i>i</i></span> having an initial value <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span>. The root of the tree is node <span class=\"tex-span\">1</span>.</p><p>This tree has a special property: when a value <span class=\"tex-span\"><i>val</i></span> is added to a value of node <span class=\"tex-span\"><i>i</i></span>, the value -<span class=\"tex-span\"><i>val</i></span> is added to values of all the children of node <span class=\"tex-span\"><i>i</i></span>. Note that when you add value -<span class=\"tex-span\"><i>val</i></span> to a child of node <span class=\"tex-span\"><i>i</i></span>, you also add -(-<span class=\"tex-span\"><i>val</i></span>) to all children of the child of node <span class=\"tex-span\"><i>i</i></span> and so on. Look an example explanation to understand better how it works.</p><p>This tree supports two types of queries:</p><ul> <li> \"<span class=\"tex-span\">1</span> <span class=\"tex-span\"><i>x</i></span> <span class=\"tex-span\"><i>val</i></span>\" — <span class=\"tex-span\"><i>val</i></span> is added to the value of node <span class=\"tex-span\"><i>x</i></span>; </li><li> \"<span class=\"tex-span\">2</span> <span class=\"tex-span\"><i>x</i></span>\" — print the current value of node <span class=\"tex-span\"><i>x</i></span>. </li></ul><p>In order to help Iahub understand the tree better, you must answer <span class=\"tex-span\"><i>m</i></span> queries of the preceding type.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains two integers <span class=\"tex-span\"><i>n</i></span> and <span class=\"tex-span\"><i>m</i></span> <span class=\"tex-span\">(1 ≤ <i>n</i>, <i>m</i> ≤ 200000)</span>. The second line contains <span class=\"tex-span\"><i>n</i></span> integers <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub></span>, <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">2</sub></span>, ..., <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>n</i></sub></span> <span class=\"tex-span\">(1 ≤ <i>a</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 1000)</span>. Each of the next <span class=\"tex-span\"><i>n</i>–1</span> lines contains two integers <span class=\"tex-span\"><i>v</i><sub class=\"lower-index\"><i>i</i></sub></span> and <span class=\"tex-span\"><i>u</i><sub class=\"lower-index\"><i>i</i></sub></span> <span class=\"tex-span\">(1 ≤ <i>v</i><sub class=\"lower-index\"><i>i</i></sub>, <i>u</i><sub class=\"lower-index\"><i>i</i></sub> ≤ <i>n</i>)</span>, meaning that there is an edge between nodes <span class=\"tex-span\"><i>v</i><sub class=\"lower-index\"><i>i</i></sub></span> and <span class=\"tex-span\"><i>u</i><sub class=\"lower-index\"><i>i</i></sub></span>.</p><p>Each of the next <span class=\"tex-span\"><i>m</i></span> lines contains a query in the format described above. It is guaranteed that the following constraints hold for all queries: <span class=\"tex-span\">1 ≤ <i>x</i> ≤ <i>n</i>, 1 ≤ <i>val</i> ≤ 1000</span>.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>For each query of type two (print the value of node <span class=\"tex-span\"><i>x</i></span>) you must print the answer to the query on a separate line. The queries must be answered in the order given in the input.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>5 5<br/>1 2 1 1 2<br/>1 2<br/>1 3<br/>2 4<br/>2 5<br/>1 2 3<br/>1 1 2<br/>2 1<br/>2 2<br/>2 4<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>3<br/>3<br/>0<br/></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>The values of the nodes are <span class=\"tex-span\">[1, 2, 1, 1, 2]</span> at the beginning.</p><p>Then value <span class=\"tex-span\">3</span> is added to node <span class=\"tex-span\">2</span>. It propagates and value -<span class=\"tex-span\">3</span> is added to it's sons, node <span class=\"tex-span\">4</span> and node <span class=\"tex-span\">5</span>. Then it cannot propagate any more. So the values of the nodes are <span class=\"tex-span\">[1, 5, 1, - 2, - 1]</span>.</p><p>Then value <span class=\"tex-span\">2</span> is added to node <span class=\"tex-span\">1</span>. It propagates and value -<span class=\"tex-span\">2</span> is added to it's sons, node <span class=\"tex-span\">2</span> and node <span class=\"tex-span\">3</span>. From node <span class=\"tex-span\">2</span> it propagates again, adding value <span class=\"tex-span\">2</span> to it's sons, node <span class=\"tex-span\">4</span> and node <span class=\"tex-span\">5</span>. Node <span class=\"tex-span\">3</span> has no sons, so it cannot propagate from there. The values of the nodes are <span class=\"tex-span\">[3, 3, - 1, 0, 1]</span>.</p><p>You can see all the definitions about the tree at the following link: <span class=\"tex-font-style-tt\">http://en.wikipedia.org/wiki/Tree_(graph_theory)</span></p></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"e3a4d4b15465de9fbd6b9b228948ab04\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - C - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"f2f8284d26a4a4d6b4f15082f9e1ab3f212e9edd\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - C - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/73366/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/73366/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/73366/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/73366/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/73366/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/73366/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/73366/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/73366/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/73366/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/73366/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/73366/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/73366/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/73366/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/73366/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/sidebar-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/a037fe51637846d9c7c725713cd840ea/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='e3a4d4b15465de9fbd6b9b228948ab04'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/73366/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/73366/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fcontest%2F383%2Fproblem%2FC%3Flocale%3Den\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"current\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='e3a4d4b15465de9fbd6b9b228948ab04'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:100%;\"><a style=\"color: black\" href=\"/contest/383\">Codeforces Round 225 (Div. 1)</a></th>\n </tr>\n <tr>\n <td class=\"left bottom\" colspan=\"1\"><span class=\"contest-state-phase\">Finished</span></td>\n </tr>\n </tbody>\n </table>\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Practice?\n <div class=\"top-links\">\n </div>\n </div>\n<div>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Want to solve the contest problems after the official contest ends? Just register for practice and you will be able to submit solutions.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"\" method=\"post\"><input type='hidden' name='csrf_token' value='e3a4d4b15465de9fbd6b9b228948ab04'/>\r\n <input type=\"hidden\" name=\"action\" value=\"registerForPractice\"/>\r\n <input type=\"submit\" name=\"submit\" value=\"Register for practice\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div> \r\n</div>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox ContestVirtualFrame borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Virtual participation <i class=\"sidebar-caption-icon las la-angle-down\"></i>\r\n\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\" \"\r\n\r\n data-page-url=\"/data/sidebarFrames\"\r\n\r\n>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests.\n\nIf you've seen these problems, a virtual contest is not for you - solve these problems in the archive.\n\nIf you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.\n\nNever use someone else's code, read the tutorials or communicate with other person during a virtual contest.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"/contest/383/virtual\" method=\"get\">\r\n <input type=\"submit\" name=\"submit\" value=\"Start virtual contest\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div>\r\n</div>\r\n <script>\r\n $(function () {\r\n $(\".ContestVirtualFrame .sidebar-caption-icon\").click(function() {\r\n $(this).toggleClass(\"la-angle-down la-angle-right\");\r\n const $target = $(this).parent().next();\r\n $target.toggle();\r\n const dataPageUrl = $target.attr(\"data-page-url\");\r\n const collapsed = $(this).hasClass(\"la-angle-right\");\r\n const params = {\r\n action: \"setCollapsed\",\r\n sidebarFrameSimpleClassName: \"ContestVirtualFrame\",\r\n collapsed\r\n };\r\n $.each($target[0].attributes, function(i, a) {\r\n const name = a.name;\r\n if (name.startsWith(\"data-extra-key-\")) {\r\n const key = a.value;\r\n const keyIndex = parseInt(name.substring(\"data-extra-key-\".length));\r\n const value = $target.attr(\"data-extra-value-\" + keyIndex);\r\n params[key] = value;\r\n }\r\n });\r\n $.post(dataPageUrl, params, function (result) {\r\n if (result[\"success\"] !== \"true\") {\r\n Codeforces.showMessage(\"Failed to save collapsed state.\");\r\n }\r\n }, \"json\");\r\n return false;\r\n });\r\n })\r\n </script>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Problem tags\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Heaps, binary search trees, segment trees, hash tables, etc\">\r\n data structures\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Dfs and similar\">\r\n dfs and similar\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Trees\">\r\n trees\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Difficulty\">\r\n *2000\r\n</span>\r\n </div>\n <div style=\"clear:both;text-align:right;font-size:1.1rem;\">\r\n <span title=\"Please login into the Codeforces\" class=\"notice\">No tag edit access</span>\r\n </div>\r\n</div>\r\n </div>\n\r\n<form id=\"addTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='e3a4d4b15465de9fbd6b9b228948ab04'/>\r\n <input name=\"action\" type=\"hidden\" value=\"addTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"5724\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<form id=\"removeTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='e3a4d4b15465de9fbd6b9b228948ab04'/>\r\n <input name=\"action\" type=\"hidden\" value=\"removeTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"5724\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<script type=\"text/javascript\">\r\n $(\".tag-box img\").click(function () {\r\n var tagName = $(this).attr(\"value\");\r\n Codeforces.confirm(\"Are you sure you want to remove this tag?\", function () {\r\n $(\"#removeTagForm input[name=tagName]\").val(tagName);\r\n $(\"#removeTagForm\").submit();\r\n }, function () {\r\n }, \"Yes\", \"No\");\r\n });\r\n\r\n $(\"#addTagLink\").click(function () {\r\n $(this).hide();\r\n $(\"#addTagLabel\").show();\r\n return false;\r\n });\r\n\r\n $(\"#addTagSelect\").change(function () {\r\n var tagName = $(this).val();\r\n if (tagName === \"\") {\r\n $(\"#addTagLabel\").hide();\r\n $(\"#addTagLink\").show();\r\n } else {\r\n $(\"#addTagForm input[name=tagName]\").val(tagName);\r\n $(\"#addTagForm\").submit();\r\n }\r\n });\r\n</script>\r\n\r\n<style type=\"text/css\">\r\n#new-resource-form tr td {\r\npadding-top: 0.5em;\r\n}\r\n#new-resource-form input:not([type=\"submit\"]) {\r\nfont-size: 0.8em;\r\n}\r\n#new-resource-form select {\r\nfont-size: 0.8em;\r\n}\r\n.new-resource-error {\r\nfont-size: 0.8em;\r\n}\r\n.resource-locale {\r\ncolor: #666;\r\nfont-family: Consolas, \"Andale Mono WT\", \"Andale Mono\", \"Lucida Console\", \"Lucida Sans Typewriter\", \"DejaVu Sans Mono\", \"Bitstream Vera Sans Mono\", \"Liberation Mono\", \"Nimbus Mono L\", Monaco, \"Courier New\", Courier, monospace;\r\n}\r\n</style>\r\n<div class=\"roundbox sidebox sidebar-menu borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Contest materials\n<div class=\"top-links\">\n</div>\n</div>\n<ul>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/10448\" title=\"Codeforces Round #225\" target=\"_blank\">Codeforces Round #225</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"2166:2167\" resourceName=\"Announcement\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n<li>\r\n<span>\r\n<a href=\"https://codeforces.com/blog/entry/10476\" title=\"Tutorial\" target=\"_blank\">Tutorial <span class=\"resource-locale\">(en)</span></a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"2170\" resourceName=\"Tutorial\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n</ul>\r\n</div></div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li class=\"current selectedLava\"><a\r\n href=\"/contest/383\">Problems</a></li>\r\n <li><a\r\n href=\"/contest/383/submit\">Submit Code</a></li>\r\n <li><a\r\n href=\"/contest/383/my\">My Submissions</a></li>\r\n <li><a\r\n href=\"/contest/383/status\">Status</a></li>\r\n <li><a\r\n href=\"/contest/383/hacks\">Hacks</a></li>\r\n <li><a\r\n href=\"/contest/383/room/1\">Room</a></li>\r\n <li><a\r\n href=\"/contest/383/standings\">Standings</a></li>\r\n <li><a\r\n href=\"/contest/383/customtest\">Custom Invocation</a></li>\r\n</ul>\r\n</div>\n\r\n <style>\r\n #facebox .content:has(.diff-popup) {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n }\r\n\r\n .testCaseMarker {\r\n position: absolute;\r\n font-weight: bold;\r\n font-size: 1rem;\r\n }\r\n\r\n .diff-popup {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n display: none;\r\n overflow: auto;\r\n }\r\n\r\n .input-output-copier {\r\n font-size: 1.2rem;\r\n float: right;\r\n color: #888 !important;\r\n cursor: pointer;\r\n border: 1px solid rgb(185, 185, 185);\r\n padding: 3px;\r\n margin: 1px;\r\n line-height: 1.1rem;\r\n text-transform: none;\r\n }\r\n\r\n .input-output-copier:hover {\r\n background-color: #def;\r\n }\r\n\r\n .test-explanation textarea {\r\n width: 100%;\r\n height: 1.5em;\r\n }\r\n\r\n .pending-submission-message {\r\n color: darkorange !important;\r\n }\r\n </style>\r\n <script>\r\n const OPENING_SPACE = String.fromCharCode(1001);\r\n const CLOSING_SPACE = String.fromCharCode(1002);\r\n\r\n const nodeToText = function (node, pre) {\r\n let result = [];\r\n\r\n if (node.tagName === \"SCRIPT\" || node.tagName === \"math\"\r\n || (node.classList && node.classList.contains(\"input-output-copier\")))\r\n return [];\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(OPENING_SPACE);\r\n }\r\n\r\n if (node.nodeType === Node.TEXT_NODE) {\r\n let s = node.textContent;\r\n if (!pre) {\r\n s = s.replace(/\\s+/g, \" \");\r\n }\r\n if (s.length > 0) {\r\n result.push(s);\r\n }\r\n }\r\n\r\n if (pre && node.tagName === \"BR\") {\r\n result.push(\"\\n\");\r\n }\r\n\r\n node.childNodes.forEach(function (child) {\r\n result.push(nodeToText(child, node.tagName === \"PRE\").join(\"\"));\r\n });\r\n\r\n if (node.tagName === \"DIV\"\r\n || node.tagName === \"P\"\r\n || node.tagName === \"PRE\"\r\n || node.tagName === \"UL\"\r\n || node.tagName === \"LI\"\r\n ) {\r\n result.push(\"\\n\");\r\n }\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(CLOSING_SPACE);\r\n }\r\n\r\n return result;\r\n }\r\n\r\n const isSpecial = function (c) {\r\n return c === ',' || c === '.' || c === ';' || c === ')' || c === ' ';\r\n }\r\n\r\n const convertStatementToText = function(statmentNode) {\r\n const text = nodeToText(statmentNode, false).join(\"\").replace(/ +/g, \" \").replace(/\\n\\n+/g, \"\\n\\n\");\r\n let result = [];\r\n for (let i = 0; i < text.length; i++) {\r\n const c = text.charAt(i);\r\n if (c === OPENING_SPACE) {\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"C\" data-uuid=\"ps_bb6a2ec6c102f927a13507025534e43970dc33c6\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">C. Propagating tree</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Iahub likes trees very much. Recently he discovered an interesting tree named propagating tree. The tree consists of <span class=\"tex-span\"><i>n</i></span> nodes numbered from <span class=\"tex-span\">1</span> to <span class=\"tex-span\"><i>n</i></span>, each node <span class=\"tex-span\"><i>i</i></span> having an initial value <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span>. The root of the tree is node <span class=\"tex-span\">1</span>.</p><p>This tree has a special property: when a value <span class=\"tex-span\"><i>val</i></span> is added to a value of node <span class=\"tex-span\"><i>i</i></span>, the value -<span class=\"tex-span\"><i>val</i></span> is added to values of all the children of node <span class=\"tex-span\"><i>i</i></span>. Note that when you add value -<span class=\"tex-span\"><i>val</i></span> to a child of node <span class=\"tex-span\"><i>i</i></span>, you also add -(-<span class=\"tex-span\"><i>val</i></span>) to all children of the child of node <span class=\"tex-span\"><i>i</i></span> and so on. Look an example explanation to understand better how it works.</p><p>This tree supports two types of queries:</p><ul> <li> "<span class=\"tex-span\">1</span> <span class=\"tex-span\"><i>x</i></span> <span class=\"tex-span\"><i>val</i></span>" — <span class=\"tex-span\"><i>val</i></span> is added to the value of node <span class=\"tex-span\"><i>x</i></span>; </li><li> "<span class=\"tex-span\">2</span> <span class=\"tex-span\"><i>x</i></span>" — print the current value of node <span class=\"tex-span\"><i>x</i></span>. </li></ul><p>In order to help Iahub understand the tree better, you must answer <span class=\"tex-span\"><i>m</i></span> queries of the preceding type.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains two integers <span class=\"tex-span\"><i>n</i></span> and <span class=\"tex-span\"><i>m</i></span> <span class=\"tex-span\">(1 ≤ <i>n</i>, <i>m</i> ≤ 200000)</span>. The second line contains <span class=\"tex-span\"><i>n</i></span> integers <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub></span>, <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">2</sub></span>, ..., <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>n</i></sub></span> <span class=\"tex-span\">(1 ≤ <i>a</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 1000)</span>. Each of the next <span class=\"tex-span\"><i>n</i>–1</span> lines contains two integers <span class=\"tex-span\"><i>v</i><sub class=\"lower-index\"><i>i</i></sub></span> and <span class=\"tex-span\"><i>u</i><sub class=\"lower-index\"><i>i</i></sub></span> <span class=\"tex-span\">(1 ≤ <i>v</i><sub class=\"lower-index\"><i>i</i></sub>, <i>u</i><sub class=\"lower-index\"><i>i</i></sub> ≤ <i>n</i>)</span>, meaning that there is an edge between nodes <span class=\"tex-span\"><i>v</i><sub class=\"lower-index\"><i>i</i></sub></span> and <span class=\"tex-span\"><i>u</i><sub class=\"lower-index\"><i>i</i></sub></span>.</p><p>Each of the next <span class=\"tex-span\"><i>m</i></span> lines contains a query in the format described above. It is guaranteed that the following constraints hold for all queries: <span class=\"tex-span\">1 ≤ <i>x</i> ≤ <i>n</i>, 1 ≤ <i>val</i> ≤ 1000</span>.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>For each query of type two (print the value of node <span class=\"tex-span\"><i>x</i></span>) you must print the answer to the query on a separate line. The queries must be answered in the order given in the input.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>5 5<br />1 2 1 1 2<br />1 2<br />1 3<br />2 4<br />2 5<br />1 2 3<br />1 1 2<br />2 1<br />2 2<br />2 4<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>3<br />3<br />0<br /></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>The values of the nodes are <span class=\"tex-span\">[1, 2, 1, 1, 2]</span> at the beginning.</p><p>Then value <span class=\"tex-span\">3</span> is added to node <span class=\"tex-span\">2</span>. It propagates and value -<span class=\"tex-span\">3</span> is added to it's sons, node <span class=\"tex-span\">4</span> and node <span class=\"tex-span\">5</span>. Then it cannot propagate any more. So the values of the nodes are <span class=\"tex-span\">[1, 5, 1, - 2, - 1]</span>.</p><p>Then value <span class=\"tex-span\">2</span> is added to node <span class=\"tex-span\">1</span>. It propagates and value -<span class=\"tex-span\">2</span> is added to it's sons, node <span class=\"tex-span\">2</span> and node <span class=\"tex-span\">3</span>. From node <span class=\"tex-span\">2</span> it propagates again, adding value <span class=\"tex-span\">2</span> to it's sons, node <span class=\"tex-span\">4</span> and node <span class=\"tex-span\">5</span>. Node <span class=\"tex-span\">3</span> has no sons, so it cannot propagate from there. The values of the nodes are <span class=\"tex-span\">[3, 3, - 1, 0, 1]</span>.</p><p>You can see all the definitions about the tree at the following link: <span class=\"tex-font-style-tt\">http://en.wikipedia.org/wiki/Tree_(graph_theory)</span></p></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=C]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== statementText) {\r\n $problem.find(\".diff-notifier\").show();\r\n\r\n $problem.find(\".diff-notifier-close\").click(function() {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n $problem.find(\".diff-notifier\").hide();\r\n });\r\n\r\n $problem.find(\"a.view-changes\").click(function() {\r\n $.post(\"/data/diff\", {action: \"getDiff\", a: previousStatementText, b: statementText}, function (result) {\r\n if (result[\"success\"] === \"true\") {\r\n Codeforces.facebox(\".diff-popup\", \"//codeforces.org/s/73366\");\r\n $(\"#facebox .diff-popup\").html(result[\"diff\"]);\r\n }\r\n }, \"json\");\r\n });\r\n }\r\n } else {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n }\r\n });\r\n });\r\n </script>\r\n\r\n\r\n<script type=\"text/javascript\">\r\n $(document).ready(function () {\r\n window.changedTests = new Set();\r\n\r\n function endsWith(string, suffix) {\r\n return string.indexOf(suffix, string.length - suffix.length) !== -1;\r\n }\r\n\r\n const inputFileDiv = $(\"div.input-file\");\r\n const inputFile = inputFileDiv.text();\r\n const outputFileDiv = $(\"div.output-file\");\r\n const outputFile = outputFileDiv.text();\r\n\r\n\r\n if (!endsWith(inputFile, \"standard input\")\r\n && !endsWith(inputFile, \"standard input\")) {\r\n inputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n if (!endsWith(outputFile, \"standard output\")\r\n && !endsWith(outputFile, \"standard output\")) {\r\n outputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n const titleDiv = $(\"div.header div.title\");\r\n\r\n\r\n\r\n String.prototype.replaceAll = function (search, replace) {\r\n return this.split(search).join(replace);\r\n };\r\n\r\n $(\".sample-test .title\").each(function () {\r\n const preId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n const cpyId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n\r\n $(this).parent().find(\"pre\").attr(\"id\", preId);\r\n const $copy = $(\"<div title='Copy' data-clipboard-target='#\" + preId + \"' id='\" + cpyId + \"' class='input-output-copier'>Copy</div>\");\r\n $(this).append($copy);\r\n\r\n const clipboard = new Clipboard('#' + cpyId, {\r\n text: function (trigger) {\r\n const pre = document.querySelector('#' + preId);\r\n const lines = pre.querySelectorAll(\".test-example-line\");\r\n return Codeforces.filterClipboardText(pre.innerText, lines.length);\r\n }\r\n });\r\n\r\n const isInput = $(this).parent().hasClass(\"input\");\r\n\r\n clipboard.on('success', function (e) {\r\n if (isInput) {\r\n Codeforces.showMessage(\"The example input has been copied into the clipboard\");\r\n } else {\r\n Codeforces.showMessage(\"The example output has been copied into the clipboard\");\r\n }\r\n e.clearSelection();\r\n });\r\n });\r\n\r\n $(\".test-form-item input\").change(function () {\r\n addPendingSubmissionMessage($($(this).closest(\"form\")), \"You changed the answer, do not forget to submit it if you want to save the changes\");\r\n const index = $(this).closest(\".problemindexholder\").attr(\"problemindex\");\r\n let test = \"\";\r\n $(this).closest(\"form input\").each(function () {\r\n const test_ = $(this).attr(\"name\");\r\n if (test_ && test_.substring(0, 4) === \"test\") {\r\n test = test_;\r\n }\r\n });\r\n if (index.length > 0 && test.length > 0) {\r\n const indexTest = index + \"::\" + test;\r\n window.changedTests.add(indexTest);\r\n }\r\n });\r\n\r\n $(window).on('beforeunload', function () {\r\n if (window.changedTests.size > 0) {\r\n return 'Dialog text here';\r\n }\r\n });\r\n\r\n autosize($('.test-explanation textarea'));\r\n\r\n $(\".test-example-line\").hover(function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n let top = 1E20;\r\n let left = 1E20;\r\n let problem = $(this).closest(\".problemindexholder\");\r\n $(this).closest(\".input\").find(\".\" + clazz).css(\"background-color\", \"#FFFDE7\").each(function() {\r\n top = Math.min(top, $(this).offset().top);\r\n left = Math.min(left, $(this).offset().left);\r\n });\r\n let testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n if (testCaseMarker.length === 0) {\r\n const html = \"<div class=\\\"testCaseMarker testCaseMarker_\" + end + \" notice\\\"></div>\";\r\n problem.append($(html));\r\n testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n }\r\n if (testCaseMarker) {\r\n testCaseMarker.show()\r\n .offset({top, left: left - 20})\r\n .text(end);\r\n }\r\n }\r\n }\r\n });\r\n }, function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n $(\".\" + clazz).css(\"background-color\", \"\");\r\n $(this).closest(\".problemindexholder\").find(\".testCaseMarker_\" + end).hide();\r\n }\r\n }\r\n });\r\n });\r\n\r\n });\r\n</script>\r\n\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 05:37:59</span> (j3).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/73366/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/73366/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/73366/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/73366/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-73366.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'8122c3f17d7e7b5b',t:'MTY5NjY0NjI4MC4wMDcwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"},"long_tags":{"kind":"string","value":"[\"Heaps, binary search trees, segment trees, hash tables, etc\", \"Dfs and similar\", \"Trees\"]"},"short_tags":{"kind":"string","value":"[\"data structures\", \"dfs and similar\", \"trees\", \"*2000\"]"},"tutorial_link":{"kind":"string","value":"https://codeforces.com/blog/entry/10476"},"tutorial_page":{"kind":"string","value":"\r\n\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"4f4c31ed5807bbee2a02378cf0944c06\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"h1\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Codeforces Round #225 — Editorial - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n \n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Codeforces Round #225 — Editorial - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/81027/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/81027/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/81027/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/81027/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/81027/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/81027/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/81027/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/81027/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/81027/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/81027/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/81027/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/81027/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/81027/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/81027/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/573cedc6b04c15481941f418269f4057/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='4f4c31ed5807bbee2a02378cf0944c06'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/81027/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fblog%2Fentry%2F10476\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='4f4c31ed5807bbee2a02378cf0944c06'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Pay attention\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n <div style=\"text-align:center;border-bottom: 1px solid rgb(185, 185, 185);margin:0 -0.5em 0.5em -0.5em;padding: 0 1em 0.5em 1em;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 1, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:51:58</span><br/><a href=\"/contestRegistration/1876\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n <div style=\"text-align:center;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 2, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:51:58</span><br/><a href=\"/contestRegistration/1877\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n\r\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div>\r\n\r\n\n <div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\n\r\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='4f4c31ed5807bbee2a02378cf0944c06'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n </label>\r\n </div>\r\n <div style=\"padding: 0 1em 1em 1em;text-align:right;\">\r\n <input style=\"height:1.65em;padding:0 0.75em;\" type=\"submit\" value=\"Find\"/>\r\n </div>\r\n </form>\r\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".handleBox\").autocomplete(\"/data/handles\", {\r\n delay: 200,\r\n width: 200,\r\n selectFirst: false,\r\n matchContains: true,\r\n minChars: 3\r\n });\r\n $(\".handleForm\").attr(\"autocomplete\", \"off\").submit(function () {\r\n var link = \"/profile/userHandle\".replace(\r\n \"userHandle\", $(this).find(\".handleBox\").val()\r\n );\r\n window.location = link;\r\n return false;\r\n });\r\n });\n </script>\n\r\n\r\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Recent actions\n <div class=\"top-links\">\n </div>\n </div>\n <div class=\"recent-actions\">\r\n <ul>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/121073\">Meta Hacker Cup 2023 Round 1</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/.Danet\" title=\"Expert .Danet\" class=\"rated-user user-blue\">.Danet</a> →\r\n <a href=\"/blog/entry/121172\">[TLE on pretest1]</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\" class=\"rated-user user-red\">Pyqe</a> →\r\n <a href=\"/blog/entry/121025\">Codeforces Round #902 (Div. 1, Div. 2, based on COMPFEST 15 — Final Round)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pranshu_Pandya\" title=\"Specialist Pranshu_Pandya\" class=\"rated-user user-cyan\">Pranshu_Pandya</a> →\r\n <a href=\"/blog/entry/121171\">An Interesting Tree Problem</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/sszcdjr\" title=\"Master sszcdjr\" class=\"rated-user user-orange\">sszcdjr</a> →\r\n <a href=\"/blog/entry/119859\">Codeforces Round 896 (Div. 1, Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/119880\">It's Happening! Meta Hacker Cup 2023 Schedule</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/DaviddeGea1\" title=\"Expert DaviddeGea1\" class=\"rated-user user-blue\">DaviddeGea1</a> →\r\n <a href=\"/blog/entry/70917\">Number of ways of dividing an array into 2 parts such that sum of each part is > k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bekh\" title=\"Master Bekh\" class=\"rated-user user-orange\">Bekh</a> →\r\n <a href=\"/blog/entry/74245\">Questions and doubts regarding Aliens DP trick</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a> →\r\n <a href=\"/blog/entry/8192\">Codeforces Round #190 — Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/hocky\" title=\"Candidate Master hocky\" class=\"rated-user user-violet\">hocky</a> →\r\n <a href=\"/blog/entry/95323\">FBHC wuining uw Day? Incwease uw stacc size! (ㅅ´ ˘ `)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/liouzhou_101\" title=\"International Master liouzhou_101\" class=\"rated-user user-orange\">liouzhou_101</a> →\r\n <a href=\"/blog/entry/87598\">Editorial of Codeforces Round #700</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/yeon_gist\" title=\"Newbie yeon_gist\" class=\"rated-user user-gray\">yeon_gist</a> →\r\n <a href=\"/blog/entry/121170\">plusMinusPermutation computing error</a>\r\n <img alt=\"Text created or updated\" title=\"Text created or updated\" src=\"//codeforces.org/s/81027/images/icons/x-update-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/altforminuscontribution\" title=\"Newbie altforminuscontribution\" class=\"rated-user user-gray\">altforminuscontribution</a> →\r\n <a href=\"/blog/entry/121162\">My screen get unexpectedly big, what should I do</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/atcoder_official\" title=\"Unrated, atcoder_official\" class=\"rated-user user-black\">atcoder_official</a> →\r\n <a href=\"/blog/entry/121120\">We will hold UNIQUE VISION Programming Contest 2023 Autumn(AtCoder Beginner Contest 323)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/YouStill_DontKnowMeYet\" title=\"Candidate Master YouStill_DontKnowMeYet\" class=\"rated-user user-violet\">YouStill_DontKnowMeYet</a> →\r\n <a href=\"/blog/entry/117659\">[GYM] Al-Baath Collegiate Programming Contest 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/ankancool\" title=\"Expert ankancool\" class=\"rated-user user-blue\">ankancool</a> →\r\n <a href=\"/blog/entry/121136\">Invitation to AstroByte 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/GeZhiyuan\" title=\"Grandmaster GeZhiyuan\" class=\"rated-user user-red\">GeZhiyuan</a> →\r\n <a href=\"/blog/entry/120943\">Codeforces Round 901 (Div. 1, Div. 2) Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a> →\r\n <a href=\"/blog/entry/120772\">PSA: Increase your stack size before the Meta Hacker Cup, here's how</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/dino_merlin\" title=\"Expert dino_merlin\" class=\"rated-user user-blue\">dino_merlin</a> →\r\n <a href=\"/blog/entry/121145\">Intuitive approach for CEOI Kangaroo?</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/icecuber\" title=\"Grandmaster icecuber\" class=\"rated-user user-red\">icecuber</a> →\r\n <a href=\"/blog/entry/70018\">CSES DP section editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bn00b\" title=\"Newbie Bn00b\" class=\"rated-user user-gray\">Bn00b</a> →\r\n <a href=\"/blog/entry/98820\">[FEATURE REQUEST : ATCODER] TOPICS TAGS AND SORTING BY SOLVE COUNT</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a> →\r\n <a href=\"/blog/entry/121163\">AtCoder Regular Contest 166 Announcement</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/windva\" title=\"Grandmaster windva\" class=\"rated-user user-red\">windva</a> →\r\n <a href=\"/blog/entry/120644\">Codeforces Round 899 (Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Misa-Misa\" title=\"Expert Misa-Misa\" class=\"rated-user user-blue\">Misa-Misa</a> →\r\n <a href=\"/blog/entry/121157\">Someone please help me understand this.</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/shivam565\" title=\"Specialist shivam565\" class=\"rated-user user-cyan\">shivam565</a> →\r\n <a href=\"/blog/entry/108348\">Total number of subarrays with sum atmost k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n </ul>\r\n </div>\r\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/recent-actions\">Detailed →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n</div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li><a\r\n href=\"/profile/fchirica\">fchirica</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/fchirica\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/fchirica\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/fchirica\">Submissions</a></li>\r\n <li><a\r\n href=\"/groups/with/fchirica\">Groups</a></li>\r\n <li><a\r\n href=\"/contests/with/fchirica\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/fchirica\">Problemsetting</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/fchirica\" style=\"text-decoration:none;color:black !important;\">fchirica's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"10531\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/10476\"> <p>Codeforces Round #225 — Editorial</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/fchirica\" title=\"Candidate Master fchirica\" class=\"rated-user user-violet\">fchirica</a>,\r\n <span class=\"format-humantime\" title=\"Jan/20/2014 22:18\">10 years ago</span>,\r\n \r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><h1><a href=\"/contest/384/problem/A\" title=\"Codeforces Round 225 (Div. 2)\">384A - Coder</a></h1><p>Usually, when you don’t have any idea how to approach a problem, a good try is to take some small examples.</p><p>So let’s see how it looks for N = 1, 2, 3, 4 and 5. With C I noted the coder and with * I noted an empty cell.</p><p><img alt=\" \" src=\"/predownloaded/8f/89/8f899efd227362957f283123a7927c7c8a300667.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>By now you should note that answer is N ^ 2 / 2 when N is even and (N ^ 2 + 1) / 2 when N is odd. Good. Generally, after you find a possible solution by taking examples, you need to prove it, then you can code it.</p><p>In order to proof it, one needs to do following steps:</p><p>1/ prove you can always build a solution having N ^ 2 / 2 (or (N ^ 2 + 1) / 2) pieces.</p><p>2/ prove that N ^ 2 / 2 (or (N ^ 2 + 1) / 2) is maximal number – no other bigger solution can be obtained.</p><p>For proof 1/ imagine you do coloring like in a chess table.</p><p><img alt=\" \" src=\"/predownloaded/50/12/50120d92bd0cea3d6a434d09ab4754ea20342351.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>The key observation is that by placing all coders on black squares of table, no two coders will attack. Why? Because a piece placed at a black square can attack only a piece placed at a white square. Again, why? Suppose chess table is 1-based. Then, a square (i, j) is black if and only if i + j is even. A piece placed at (i, j) can attack (i + 1, j), (i – 1, j) (i, j + 1) or (i, j – 1). The sum of those cells is i + j + 1 or i + j – 1. But since i + j is even, i + j + 1 and i + j – 1 are odd, hence white cells.</p><p>Depending on parity of N, number of black cells is either N ^ 2 / 2 or (N ^ 2 + 1) / 2. For N even, one can observe that there are equal amount of black and white cells. Total number of cells is N ^ 2, so number of black cells is N ^ 2 / 2. For N odd, number of black cells is number of white cells + 1. We can imaginary add a white cell to the board. Now, number of black cells will be also equal to number of white cells, so answer is (N ^ 2 + 1) / 2.</p><p>2/ Two coders attack each other if they are placed at two adjacent cells, one black and other one white. One needs to prove that adding more than number from 1/ will cause this to happen. If you place a coder at a white cell, you won’t be able to place at least one coder at a black cell, so in best case you don’t win anything by doing this. Hence, it’s optimally to place all coders on same color cells. Since cells colored in black are always more or equal to white ones, it’s always optimally to choose black color. But number from 1/ is the number of cells having black color. Adding one more piece will force you to add it to a white color cell. Now, you’ll have a piece placed at a black colored cell and one placed at an adjacent white colored cell, so two coders will attack. Hence, we can’t place more than number from 1/ pieces.</p><p>Code: <a href=\"http://pastie.org/8651801\">http://pastie.org/8651801</a></p><h1><a href=\"/contest/384/problem/B\" title=\"Codeforces Round 225 (Div. 2)\">384B - Multitasking</a></h1><p>Let’s start by saying when array A[] is sorted:</p><p>1/ is sorted in ascending order when i < j and A[i] <= A[j]. It is NOT sorted when i < j and A[i] > A[j].</p><p>2/ is sorted in descending order when i > j and A[i] <= A[j]. It is NOT sorted when i > j and A[i] > A[j].</p><p>Iahub can choose 2 indices i, j and swap values when A[i] > A[j]. If A[i] <= A[j], he’ll ignore operation. Hence, if he wants to sort all arrays in ascending order, he chooses indices i, j when i < j and perform operation. Otherwise, in all his operations he uses indices i, j such as i > j. A “good” operation is when choosing indices i < j for ascending order sorting and i > j for descending order sorting. By doing only good operations, after an array is sorted, it will stay sorted forever (for a sorted array, all good operations will be ignored).</p><p>From here we get our first idea: use any sorting algorithm you know and sort each array individually. When print swaps done by sorting algorithm chosen, print them as good operations. However, sorting each array individually can cause exceeding M * (M — 1) / 2 operations limit. Another possible solution would be, after you did an operation to an array, to update the operation to all arrays (you printed it, so it counts to M * (M — 1) / 2 operations limit; making it to all arrays will help sometimes and in worst case it won’t change anything). However, you need to code it very careful in order to make this algorithm pass the time limit. Doing this in a contest is not the best idea, especially when implementation could be complicated and you have no guarantee it will pass time limit.</p><p>So what else can we do? We can think out of box. Instead of sorting specific N arrays, you can sort all possible arrays of length M. Find a sequence of good operations such as, anyhow I’d choose an array of size M, it will get sorted ascending / descending.</p><p>I’ll show firstly how to do for ascending sorting. At position 1 it needs to be minimal element. Can we bring minimal element there using good operations? Yes. Just do “1 2” “1 3” “1 4” ... “1 M”. It basically compares element from position 1 to any other element from array. When other element has smaller value, swap is done. After comparing with all M elements, minimal value will be at position 1. By now on I’ll ignore position 1 and move to position 2. Suppose array starts from position 2. It also needs minimal value from array, except value from position 1 (which is no longer in array). Hence doing “2 3” “2 4” “2 5” ... “2 M” is enough, by similar reasons. For a position i, I need minimal value from array, except positions 1, 2, ..., i – 1. I simply do “i i+1” “i i+2” ... “i M-1” “i M”. By arriving at position i, array will be sorted ascending. The algorithm is simply:</p><p>for (int i = 1; i < M; ++i)</p><p>for (int j = i + 1; j <= M; ++j)</p><p>cout << i << “ “ << j << “\\n”;</p><p>This algorithm does exactly M * (M — 1) / 2 moves.</p><p>Can you find out how to sort array in descending order? Try to think yourself, then if you don’t get it read next. At first position of a descending array it needs to be maximal value. Similarly to ascending order, we can do “2 1” “3 1” “4 1” ... “M 1”. When I’m at a position i and I compare its value to value from position 1, doing operation “i 1” checks if A[i] > A[1]. If so, it swaps A[i] and A[1], so position 1 will contain now the maximum value so far. Similarly to logic from ascending order, when I’m at position i, I need maximum value from array except positions 1, 2, ..., i – 1, so I do “i+1 i” “i+2 i” ... “M i”. Algorithm is:</p><p>for (int i = 1; i < M; ++i)</p><p>for (int j = i + 1; j <= M; ++j)</p><p>cout << j << “ “ << i << “\\n”;</p><p>Obviously, this does as well M * (M — 1) / 2 operations worst case. All algorithm is about 10 lines of code, much better than other solution, which requires two manually sorts and also has a chance to exceed TL.</p><p>Code: <a href=\"http://pastie.org/8651809\">http://pastie.org/8651809</a></p><h1><a href=\"/contest/384/problem/C\" title=\"Codeforces Round 225 (Div. 2)\">384C - Milking cows</a></h1><p>A good strategy to approach this problem is to think how optimal ordering should look like. For this, let’s calculate for each 2 different cows i and j if cow i needs to be milked before or after cow j. As we’ll show, having this information will be enough to build optimal ordering. It is enough to consider only cases when i < j, case when i > j is exactly the opposite of case i < j. For formality, I’ll call the optimal ordering permutation and lost milk the cost of permutation.</p><p>So, for an optimal permutation P let’s take 2 numbers i < j and see in which cases i should appear before j in permutation (i is before j if P[pos1] = i, P[pos2] = j and pos1 < pos2; otherwise we’ll call i is after j). We have 4 possible cases:</p><p>1/ A[i] = 0 and A[j] = 0</p><p>If we put i before j, no additional cost will be added. Since j is in right of i and i only adds cost when it finds elements in left of i, j won’t be affected when processing i. When processing j, i will be already deleted so it won’t affect the cost either. Hence, we can put i before j and no cost will be added.</p><p>2/ A[i] = 0 and A[j] = 1</p><p>Here, i and j can appear in arbitrary order in permutation (i can be before or after j). No matter how we choose them, they won’t affect each other and cost will remain the same.</p><p>3/ A[i] = 1 and A[j] = 0</p><p>As well, here i and j can appear in arbitrary order. If we choose i first, j will be in right of it, so cost of permutation will increase by one. If we choose j first, i will be in left of it so cost of permutation will increase as well. No matter what we do, in this case cost of permutation increases by 1.</p><p>4/ A[i] = 1 and A[j] = 1</p><p>Here, i needs to be after j. This adds 0 cost. Taking i before j will add 1 cost to permutation (since j is in right of i).</p><p>Those 4 cases show us how a minimal cost permutation should look. In a permutation like this, only case 3/ contributes to final cost, so we need to count number of indices i, j such as i < j and A[i] = 1 and A[j] = 0 (*). If we show a permutation following all rules exists, task reduces to (*).</p><p>By cases 2/ and 3/ it follows that in an optimal permutation, it only matters order of elements having same value in A[]. We can put firstly all elements having value 0 in A[], then all elements having value 1 in A[]. We can order elements having value 0 by case 1/ and elements having value 1 by case 4/. More exactly, suppose i1 < i2 < ... < im and (A[i1] = A[i2] = ... = A[im] = 0) and j1 > j2 > ... > jn (A[j1] = A[j2] = ... = A[jn] = 1). Then, a permutation following all rules is {i1, i2, ..., im, j1, j2, ..., jn}. This permutation can always be built.</p><p>Hence, task reduces to (*): count number of indices i, j such as i < j and A[i] = 1 and A[j] = 0. We can achieve easily an O(N) algorithm to do this. Let’s build an array cnt[j] = number of 0s in range {j, j + 1, ..., N} from array A. We can easily implement it by going backwards from N to 1. The result is sum of cnt[i], when A[i] = 1.</p><p>Code: <a href=\"http://pastie.org/8651813\">http://pastie.org/8651813</a></p><h1><a href=\"/contest/384/problem/D\" title=\"Codeforces Round 225 (Div. 2)\">384D - Volcanoes</a></h1><p>Our first observation is that if there is a path from (1, 1) to (N, N), then the length of path is 2 * N – 2. Since all paths have length 2 * N – 2, it follows that if there is at least one path, the answer is 2 * N – 2 and if there isn’t, the answer is -1. How to prove it? Every path from (1, 1) to (N, N) has exactly N – 1 down directions and exactly N – 1 right directions. So, total length for each path is N – 1 + N – 1 = 2 * N – 2. </p><p>So we reduced our problem to determine if there is at least one path from (1, 1) to (N, N). This is the challenging part of this task, considering that N <= 10 ^ 9. How would you do it for a decently small N, let’s say N <= 10^3 . One possible approach would be, for each row, keep a set of reachable columns. We could easily solve this one by doing this: if (i, j) denotes element from ith row and jth column, then (i, j) is (is not) reachable if:</p><p>if (i, j) contains a volcano, then (i, j) is not reachable. Otherwise, if at least one of (i – 1, j) and (i, j – 1) is reachable, then (i, j) is reachable. Otherwise, (i, j) is not reachable.</p><p>What’s the main problem of this approach? It needs to keep track of 10^9 lines and in worst case, each of those lines can have 10^9 reachable elements. So, worst case we need 10^9 * 10^9 = 10^18 operations and memory.</p><p>Can we optimize it? We can note for beginning that we don’t need to keep track of 10^9 lines, only m lines are really necessarily. We need only lines containing at least one obstacle (in worst case when each line contains only one obstacle, we need m lines). How to solve it this way? Suppose line number x contains some obstacles and lines x + 1, x + 2, x + 3 do not contain any obstacle. Suppose we calculated set S = {y | cell (x, y) is reachable}. How would look S1, S2, S3 corresponding to lines x + 1, x + 2, x + 3? For S1, we can reach cell (x + 1, ymin), where ymin is minimal value from set S. Then, we can also reach {ymin + 1, ymin + 2, ..., N}, by moving right from (x + 1, ymin). So S1 = {ymin, ymin + 1, ..., N}. How do S2 and S3 look? It’s easy to see that they’ll be as well {ymin, ymin + 1, ..., N}. So we get following optimization: suppose set of lines containing at least one obstacle is {L1, L2, ..., Lk}. We need to run algorithm only for lines L1, L1 + 1, L2, L2 + 1, L3, L3 + 1, ..., Lk, Lk + 1.</p><p>It looks like we didn’t make anything with this optimization. Even if we calculate for m lines, each line can still have 10^9 reachable positions. So worst case we perform 10^14 operations. We need something better for managing information from a line. You can note that for a given line y, there are a lot of positions having consecutive values. There are a lot of positions (x, y) and (x, y + 1) both reachable. This should give us following idea: what if instead of keeping reachable positions, we keep reachable ranges? That is, for each line x we keep a set of ranges S = {(a, b) | all cells (x, k) with a <= k <= b are reachable}. </p><p>How many ranges can it be for a line? If the line contains m obstacles, there are m + 1 ranges. Suppose for line x all cells are reachable, but for line x + 1 cells (x + 1, 3) (x + 1, 5) (x + 1, N – 1) are blocked. Then, the ranges of reachable cells are [1, 2] [4, 4], [6, N – 2] and [N, N]. By now, we get worst case m lines and worst case each line having m elements, so in worst case we’d have to handle m * m = 10 ^ 10 events. This may still look too much, but happily this bound is over estimated. If a line has o obstacles, there can be at most o + 1 ranges. If lines L1, L2, ..., Lk have {o1, o2, ..., ok} obstacles, there’ll be at most o1 + o2 + ... + ok + k ranges. But o1 + o2 + ... + ok = m and also k is at most m (proved above why we’re interested in at most m lines), so in worst case we get m + m = 2 * m ranges. Yaay, finally a decent number of states for this problem :)</p><p>So, we iterate each line we’re interested in. Let’s find set of ranges for this line, thinking that all cells from line above are reachable. This is easy to do. After we get our ranges like all cells from above can be visited, let’s think how having obstacles above can influence current ranges. After adding ranges from above, current ranges can’t increase (obviously), they can only decrease, remain the same or some of them can become empty. So, let’s take each range [a, b] from current line and see how it will transform after adding ranges from previous line. </p><p>Given range [a, b], it can transform only in [a’ , b] with a’ >= a. If a’ > b, then obviously range is empty. Why second number of range keeps constant? Let a’ smallest reachable column from current line which is in range [a, b]. It’s enough to check a’ >= a, as if a’ > b, range will be empty. It’s obviously why we need to keep a’ smallest value possible >= a: we’re interested to keep range as big as possible and as less as we cut from left, as big it is. Once we’ve found a’ in range [a, b] (or a’ > b if range is empty) all cells {a’ + 1, a’ + 2, ..., b} are reachable as well by going right from a’, so if interval is not empty, then second number defining it remains b.</p><p>Next question is how to find a’ fast enough. In order a point a’ to be reachable on current range, it also needs to exist a range on previous line containing it. If the range from previous line is [pa, pb] then a’ needs to follow 3 conditions:</p><p>a’ minimal such as</p><p>pa <= a’ <= pb</p><p>a’ >= a</p><p>What if instead of finding a’ we find [pa, pb]? Then a’ is max(pa, a). In order a’ to be as small as possible, since a is constant, pa needs to be as small as possible. So we reduced it to:</p><p>pa minimal pb >= a’ >= a <=> pb >= a</p><p>Intervals from previous line are disjoint, no 2 intervals cross each other. It means that if pb is minimal, than pa is minimal too (if we increase pb, then pa will increase too, so it won’t be minimal). Hence, you need to find an interval [pa, pb] such as pb is minimal and pb >= a. Then, a’ is max(a, pa). This is easy to do if we sort all intervals from previous line increasing by second value (pb), then we binary search for value a. </p><p>Finally, after running algorithm for all lines, last range from last line has second number N (assuming ranges are sorted increasing by second value), then there exist a path, otherwise there does not exist. This algorithm should run O(m * logm) worst case, good enough to pass. </p><p>Code: <a href=\"http://pastie.org/8651817\">http://pastie.org/8651817</a></p><h1><a href=\"/contest/384/problem/E\" title=\"Codeforces Round 225 (Div. 2)\">384E - Propagating tree</a></h1><p>This is kind of task that needs to be break into smaller subproblems that you can solve independently, then put them together and get solution.</p><p>Let’s define level of a node the number of edges in the path from root to the node. Root (node 1) is at level 0, sons of root are at level 1, sons of sons of root are at level 2 and so on.</p><p>Now suppose you want to do an operation of type 1 to a node x. What nodes from subtree of x will be added +val (a positive value)? Obviously, x will be first, being located at level L. Sons of x, located at level L + 1 will be added –val. Sons of sons, located at level L + 2, will be added value +val again. So, nodes from subtree of x located at levels L, L + 2, L + 4, ... will be added a +val, and nodes located at levels L + 1, L + 3, L + 5 will be added a –val. Let’s take those values of L modulo 2. All nodes having remainder L modulo 2 will be added a +val, and nodes having reminder (L + 1) modulo 2 will be added –val. In other words, for a fixed x, at a level L, let y a node from subtree of x, at level L2. If L and L2 have same parity, +val will be added to y. Otherwise, -val will be added to y.</p><p>From here we have the idea to split nodes of tree in 2 sets – those being located at even level and those being located at odd level. What still makes the problem hard to solve? The fact that we have a tree. If nodes from a subtree would be a contiguous sequence instead of some nodes from a tree, problem would be simpler: the problem would reduce to add / subtract values to all elements of a subarray and query about a current value of an element of array. So, how can we transform tree to an array, such as for a node x, all nodes from subtree of x to be a subarray of array?</p><p>The answer is yes. We can do this by properties of DFS search. Before reading on, make sure that you know what is discovery time and finish time in a DFS search. Let’s build 3 arrays now – discover[], representing nodes in order of their discover times (a node is as before in discover as it has a small discover time), begin[] = for a node, in which time it was discovered and end[] = what’s last time of a discovered node before this node finishes. For a subtree of x, all nodes in the subtree are nodes in discover from position begin[x] to end[x].</p><p>Example: suppose you have tree 1-5; 1-6; 6-7; 6-4; 4-2; 4-3</p><p>Discover is {1, 5, 6, 7, 4, 2, 3}.</p><p>begin is {1, 6, 7, 5, 2, 3, 4}.</p><p>end is {7, 6, 7, 7, 2, 7, 4}.</p><p>What’s subtree of node 6? elements of discover from position begin[6] to end[6]. In this case, from 3 to 7, so elements {6, 7, 4, 2, 3}. You can see it’s correct and take more examples if you want :)</p><p>Now, we reduced problem to: you’re given an array A. you can perform 2 operations:</p><p>1/ increase all elements from a range [x, y] to a value val (val can be negative, to treat subtractions)</p><p>2/ what’s current value of an element from position pos.</p><p>Those who solved “Iahub and Xors” from my last round, CF 198, should probably say they saw something similar before. If you didn’t solve problem before, I encourage you to do it after you solve this one, it uses a similar idea to what will follow now. Also, if you don’t know Fenwick trees, please read them before moving on. An alternative would be for this task using segment trees with lazy update, but I see this one more complicated than needed.</p><p>I’ll use now a not so common approach when dealing with data structures. Instead of keeping in a node the result, like you usually do, I’ll keep just an auxiliary information. So what algorithm proposed does:</p><p>Let A an array, initially with all elements 0.</p><p>When you need to update range [x, y] with value val, you simply do A[x] += val and A[y + 1] -= val.</p><p>When you need to answer a query about position pos, you output A[1] + A[2] + ... + A[pos].</p><p>Implemented brute force, you get O(1) per update and O(N) per query. However, these both are operations supported by a Fenwick tree, so you can get O(logN) per operation.</p><p>It may not be very clear why this algorithm works. Let’s take a closer look: an update needs to add value val only to range [x, y]. When you query a position pos, let’s see if algorithm handles it correctly:</p><p>1/ pos < x. In this case, result must not be affected by my update. Since pos < x and I only updated 2 values with indices >= x, when doing A[1] + A[2] + ... + A[pos] it won’t matter at all I did that update – at least not for this query.</p><p>2/ x <= pos <= y. Here, for a pos, I need to add value val only once. We add it only at A[x] – in this way it will be counted once, and it will be considered for each elements from range [x, y] (since an element at position p from range [x, y] has p >= x, in A[1] + A[2] + ... + A[p] I’ll have to consider A[x]).</p><p>3/ pos > y. Here I don’t have to consider the query. But it would be considered when processing A[x]. But if I add to A[y + 1] value –val I’ll just cancel the value previously added.</p><p>Code (actually we use just one Fenwick tree instead of 2, can you think why it works? :) ) : <a href=\"http://pastie.org/8651824\">http://pastie.org/8651824</a></p><h1><a href=\"/contest/383/problem/D\" title=\"Codeforces Round 225 (Div. 1)\">383D - Antimatter</a></h1><h2>Author's solution</h2><p>The problem is: given an array, iterate all possible subarrays (all possible elements such as their indexes are consecutive). Now, for a fixed subarray we need to know in how many ways we can color its elements in black and white, such as sum of black elements is equal to sum of white elements. The result is sum of this number, for each subarray.</p><p>Let’s solve an easier problem first. This won’t immediately solve the harder version, but it will be useful later. Suppose you’ve fixed a subarray. In how many ways can you color it with black and white? Suppose subarray has N elements and sum of them is M. Also, suppose for a coloring, sum of blacks is sB and sum of whites is sW. For coloring to be valid, sB = sW. But we also know that sB + sW = M (because each element is colored by exactly one color). We get that 2 * sB = M, so sB = M / 2. The problem is now: in how many ways can we color elements in black such as sum of blacks is M / 2 (after we fix a black coloring, we color with white non colored elements; sum of white colored elements is also M / 2). This is a well known problem: Knapsack problem. Let ways[i][j] = in how many ways one can obtain sum j from first i elements. When adding (i + 1) object, after ways[i] is calculated, for a fixed sum j we can do 2 things: add (i + 1) object to sum j or skip it. Depending of what we chosen, we add value ways[i][j] to ways[i + 1][j + value[i + 1]] or to ways[i + 1][j]. The result is in ways[N][M / 2]. This works in O(N * M) time.</p><p>An immediate solution can be obtained now: take all subarrays and apply above approach. This leads to an O(N ^ 2 * M ^ 2) solution, which is too much. One can reduce complexity to O(N ^ 2* M) by noting that processing subarray [i, j] can be done with already calculated values for subarray [i, j – 1]. Hence, instead of adding N elements, it’s enough to add 1 element to already calculated values (element from position j). Sadly, O(N ^ 2 * M) is still too slow, so we need to find something better. The solution presented below will look forced if you didn’t solve some problems with this technique before. It’s hard to come with an approach without practicing this kind of tasks. But don’t worry, as much as you practice them, as easily you’ll solve those problems.</p><p>We’ll solve task by divide and conquer. Complexity of this solution is O(N * M * logN). Let f(left, right) a function that counts number of colorings for each subarray [i, j], such as subarray [i, j] is included in subarray [left, right] (left <= i <= j <= right). Answer is in f(1, N). The trick is to define a value med = (left + right) / 2 (very frequent trick in divide and conquer problems, called usually a median). We can next classify [i, j] subarrays in 3 types:</p><p>1/ i <= med j <= med</p><p>2/ i > med j > med</p><p>3/ i <= med j > med</p><p>We can solve 1/ and 2/ by calling f(left, med) and f(med + 1, right). The remained problem is when i <= med and j > med. If we solve 3/ in O((right – left) * M) time, this will be enough to overall achieve O(N * M * logN) (for this moment trust me, you’ll see later why it’s so :) ).</p><p>Let’s denote by i1 last i1 elements from subarray [left, med]. Also, let’s note by i2 first i2 elements from subarray [med + 1, right]. For example, let left = 1 and right = 5, with array {1, 2, 3, 4, 5}. med is 3 and for i1 = 2 and i2 = 1, “left” subarray is {2, 3} and “right” subarray is {4}. By iterating i1 from 1 to med – left + 1 and i2 from 1 to right – med and then unite subarrays i1 and i2, we obtain all subarrays described in 3/ . Let’s denote by j1 sum of a possible black coloring of i1. Similarly, j2 is sum of a possible black coloring of i2.</p><p>Suppose we fixed i1, i2, j1 and j2. When it’s the coloring valid? Let S sum of united subarrays i1 and i2 (S = value[med – i1 + 1] + value[med – i1 + 2] + ... + value[med] + value[med + 1] + ... + value[med + i2 – 1] + value[med + i2]). Now it’s time to use what I explained at the beginning of solution. The coloring is good only when j1 + j2 = S / 2. We can rewrite the relation as 2 * (j1 + j2) = sum_of_elements_from_i1 + sum_of_elements_from_i2. We can rewrite it even more:</p><p>2 * j1 + 2 * j2 — sum_of_elements_from_i1 — sum_of_elements_from_i2 = 0</p><p>2 * j1 – sum_of_elements_from_i1 = sum_of_elements_from_i2 – 2 * j2 = combination_value</p><p>This relation is the key of solving problem. You can see now that relation is independent in “left” and “right” side. We calculate left[i1][j1] and right[i2][j2] = in how many ways can I obtain sum of blacks j1 (j2) from first i1 (i2) from left (right) side. Let’s calculate also count[value] = in how many ways can I obtain combination_value equal to value in the right side. For some fixed (i2, j2) I add to count[sum_of_elements_from_i2 – 2 * j2] value right[i2][j2]. In this way count[] is calculated correctly and completely. Now, let’s fix a sum (i1, j1) in the left side. We’re interested how many good colorings are such as there exist a coloring of j1 in i1 elements (the endpoint of “left” is fixed to be i1 and I need to calculate endpoints i2 for right, then to make colorings of i2). A coloring is good if combination_value of (i1, j1) and (i2, j2) is equal. Hence, I need to know in how many ways I can color i1 elements to obtain sum j1 and also I need to know in how many ways I can color elements from right to obtain same combination_value as it’s in the left. It’s not hard to see that answer for a fixed (i1, j1) is left[i1][j1] * count[2 * j1 – sum_of_elements_from_i1]. This takes O((right – left) * M) time.</p><p>The only thing remained in the problem is to see why complexity is O(N * M * logN). We can assume N is a power of 2 (it not, let’s round N to smallest power of 2 bigger than N; complexity for N is at least as good as complexity for this number). Draw a binary complete tree with N nodes. Each node corresponds to an appeal of f(). For a level, exactly O(N * M) operations are performed. To see why:</p><p>For level 1, there’ll be 1 node performing N * M operations.</p><p>For level 2, there’ll be 2 nodes performing (N / 2) * M operations. Summing up we get O(N * M).</p><p>For level 3, there’ll be 4 nodes performing (N / 4) * M operations. Summing up we get O(N *M) as well.</p><p>and so on.</p><p>So for each level we perform O(N * M) operations. A binary complete tree has maximum O(logN) levels, so overall complexity is O(N * M * logN).</p><p>Code: <a href=\"http://pastie.org/8651826\">http://pastie.org/8651826</a></p><h2>Solution fount by contestants</h2><p>This was totally unexpected to us :) Good job finding it, you guys are really smart. </p><p>We observe that x units of antimatter is the same thing as -x units of matter. Then we can consider that an element produces either x or -x units of matter. A valid substring is one that can have the sum of the elements 0. The problem is reduced to finding how many different substrings can we have with sum 0 (a substring is different than another one if it has different indices, or if at least one element produces matter in one and antimatter in the other).</p><p>This problem can be solved with dynamic programming. We will hold D[i][j] = the number of substrings that end in element i, and have sum j. It's easy to see that D[i + 1][j] = D[i][j — x] + D[i][j + x], where x is the value of the current element (we can put either -x or x). After we finish computing all the values for current i, we add to the solution D[i][0] (how many valid substrings do we have). After that, we add 1 to D[i][0], meaning that there is an empty substring starting at position i (however, we don't need to add it to the answer).</p><p>For a code, check passing submissions during contest. </p><h2><a href=\"/contest/383/problem/E\" title=\"Codeforces Round 225 (Div. 1)\">383E - Vowels</a></h2><h2>Author's solution</h2><p>Let's iterate over all possible vowel sets. For a given set {x1, x2, ..., xk} we're interested in number of correct words from dictionary. After a precalculation, we can do it in O(k).</p><p>Suppose our current vowel set is {x1, x2, ..., xk}. How many words are covered by the current vowels? By definition, we say a word is covered by a set of vowels if at least one of 3 letters of word is in vowel set. We can calculate this number using principle of inclusion and exclusion. We’ll denote by |v1, v2, v3, ...| = number of words containing ALL of vowels v1, v2, v3, ... . Using principle of inclusion and exclusion we get:</p><p>number_of_words_covered = |x1| + |x2| + .. + |xk| — |x1, x2| — |x1, x3| — .... + |x1, x2, x3| + |x1, x2, x4| + .... + |xk-2, xk-1, xk|. This formula is simply a reformulation of principle of inclusion and exclusion. You can easily observe that |v1, v2, ..., vk| makes sense only when k is at most 3, as no word from input can contain 4 or more letters (and hence can’t contain 4 or more vowels). </p><p>Example:</p><p>Suppose words are abc, abd and bcd. </p><p>|a| = 2 (first 2 words both contain character a).</p><p>|a, b| = 2 (as well, first 2 words contain characters a and b).</p><p>|b| = 3 (all 3 words contain character b).</p><p>|a, b, d| = 1 (only second word contains all 3 characters).</p><p>Also, note how principle of inclusion and exclusion works. number of words covered for vowels {a, b} is |a| + |b| — |a, b| = 2 + 3 – 2. Indeed, answer is 3.</p><p>We divide our problem in 3 subproblems. First one, for a vowel set, compute sum of |a|, where a is a letter from subset. Second, compute sum of |a, b|, where both a and b are letters from set. Third, compute sum of |a, b, c|, where a, b, c are letters from set. As stated, the answer is number_from_1st_step + number_from_3rd_step – number_from_2nd_step. If you followed me, you’ll see that we want to compute results for each subproblem in O(queryLetters).</p><p>First subproblem can be solved trivially in O(queryLetters). Let array single[], with following meaning: single[c] is how many words contain character c. It can be trivially precomputed in O(24 * N). Note that if a word contains twice/third times a character c, it needs to be counted only one (e.g. word aba will add only 1 to single[a]). For compute result of this subproblem for a given set of vowels, I’ll take all letters from set. If letter belongs to set, I add to result single[letter]. This step can be also be solved in O(1), but there’s no need, since other subproblems allow only an O(queryLetters) solution. </p><p>For second and third subproblems it’s a little more difficult. I’ll present here how to solve second subproblem and some hints for third one (if you understand second, with hints you should be able to solve third one by your own).</p><p>Similarly to first step, I’ll define a matrix double[c1][c2] = how many words contain both characters c1 and c2. A trivially solution would be, for a given vowel set, take all combinations of letters c1 and c2 that belong to set and add to result value double[c1][c2]. However, this solves each query in O(queryLetters^2), which is too slow.</p><p>Note, if we’d have 12 letters, instead of 24, this approach would be fast enough. From here it comes a pretty classical idea in exponential optimization: meet in the middle attack. We split those 24 letters in 2 groups: first 12 letters and last 12 letters. The answer for a subset is sum of double[c1][c2] (when c1 and c2 belong to current vowel set) when</p><p>1/ c1 and c2 belong to first 12 letters</p><p>2/ c1 and c2 belong to last 12 letters</p><p>3/ c1 belongs to first 12 letters and c2 belongs to last 12 letters</p><p>1/ and 2/ can be immediately precalculated as stated above, in O(2 ^ 12 * 12 ^ 2). We’ll remember results for each half using bitmasks arrays. Let Half1[mask] = sum over double[c1][c2], when c1 and c2 are in first 12 letters and correspond to 1 bits of mask. Half2[mask] is defined similarly, but for last 12 letters (e.g. subset {a, c, d} corresponds to bitmask 2^0 + 2^2 + 2^3 = 13 in first half and subset {m, n, p} corresponds to bitmask 2^0 + 2^1 + 2^3 = 11 for second half). Now, for a given subset, one can answer first 2 parts in O(queryCount) worst case (read input for a query and convert it to bitmasks). </p><p>How to answer 3? With another precalculation, of course. We know c1 letter needs to be in first 12 letters and c2 needs to be in last 12 letters. The precalculation we do here is: mixed_half[mask][i] = sum over |c1, c2|, when c1 belongs to first half and is a 1 bit of mask and c2 is i-th character of second half. Hence, for a query, we can fix character from second half (c2, by iteration of query letters from second half) and know sums of |c1, c2| between it and all available characters from first half after we do this precalculation. Also, precalculation is done trivially in O(2 ^ 12 * 12^2): fix mask, fix i and then iterate over 1 bits from mask and add double[c1][c2]. </p><p>Third subproblem is left, but it can be done similarly to second one. Instead of double[c1][c2], we’ll have triple[c1][c2][c3] = how many words contain all 3 characters c1, c2 and c3? We also do meet in the middle here, divide those 24 letters into 2 sets of 12 letters. We have 4 cases:</p><p>1/ c1, c2, c3 belong to first half</p><p>2/ c1, c2, c3 belong to second half</p><p>3/ c1, c2 belong to first half and c3 to second half</p><p>4/ c1 belongs to first half and c2, c3 to second half</p><p>1/ and 2/ are done brute force, like in second subproblem (the only difference is we choose 3 characters instead of 2, having complexity O(2 ^ 12 * 12 ^ 3)). For 3/ and 4/ we also precompute 2 matrixes: </p><p>mixed_two_one[mask][i] = c1 and c2 belong to mask from first half and c3 is i-th character from second half </p><p>and </p><p>mixed_one_two[mask][i] = c1 is i-th character from first half and c2, c3 belong to mask from second half. </p><p>Those can also be calculated in O(2 ^ 12 * 12^3).</p><p>So precalculation part is O(2 ^ 12 * 12 ^ 3) = 7077888 operations.</p><p>For calculate answering queries complexity, take all numbers from 0 to 2^24 — 1 and sum their bit count. This is a well known problem, the sum is 0 * C(24, 0) + 1 * C(24, 1) + ... + 24 * C(24, 24) = 201326592. In total we get 208404480 operations. C++ source makes them in 2 seconds. </p><p>Code: <a href=\"http://pastie.org/8651829\">http://pastie.org/8651829</a></p><h2>Solution fount by contestants</h2><p>Like in D1 D task, official solution was over complicated. This solution is more simple to understand, code and it's more elegant. If someone wants to complicate his life, (s)he can code also official solution :)</p><p>Let's start by assigning a bitmask to each word in following way: ith bit is 1 if and only if letter ('a' + i) appears in the current word. For example, for word acd, its bitmask is 2^0 + 2^2 + 2 ^ 3 = 13 and for word aab its bitmask is 2^0 + 2^1 = 3. After reading the words from dictionary, we store a matrix cnt[mask] = how many words from dictionary correspond to mask?</p><p>We iterate bitmasks from 0 to 2^24 — 1, this time corresponding to each possible question of Iahubina. Let's focus on a bitmask X. We need to get sum of cnt[mask], when mask and X share at least one common bit having value 1 (formally (X AND mask) > 0). In order to do this, we need a reduction which may be not so obvious. </p><p>What if instead of counting all words containing at least one of vowels {w1, w2, ..., wk} we count all words which don't contain ANY of vowels {w1, w2, ..., wk}? Suppose this number is ret. Then, all words containing at least one of vowels is N — ret. From all words, we erase those words which do not contain any vowels from set {w1, w2, ..., wk} (and which obviously are wrong words). Obviously, it's left only words containing at least one vowel, so good words. Now, for a word not to contain any of vowels {w1, w2, ..., wk} it needs to contains ONLY vowels from set {"a", "b", "c", ..., "x"} \\ {w1, w2, ..., wk} (set of allowed letters from which we erased vowels w1, w2, ..., wk}. </p><p>And this is reduction we needed. For a bitmask X we need to calculate sum of cnt[mask], where mask is a subset of X (we can set some bits from X from 1 to 0 in order to obtain mask). For a mask, let's keep this sum in res[mask]. We can calculate res array using divide and conquer.</p><p>Let's make a function solve(left, right), which completes array res in the way described above, if we consider only elements cnt[k] with left <= k < right (for simplicity, I'll consider elements which do not lie in this range to be equal to 0). Now we need to solve for a range [left, right]. Let's have in res1[] = solve(left, med) and in res2[] = solve(med, right), where med = (left + right) / 2. We need to put together res1[] and res2[] in order to obtain res[].</p><p>for (int i = left; i < med; ++i) res[i] = res1[i];</p><p>Numbers in [left, med] have most significant bit equal to 0. We can only keep it 0 and add what we calculated before. We can't add any element from res2[], because those elements have most significant bit equal to 1 and we're not allowed to change bit 0 into bit 1.</p><p>for (int i = med; i < right; ++i) res[i] = res1[i — med] + res2[i];</p><p>Here, most significant bit is 1. Adding res1[] corresponds to changing bit from 1 to 0, adding res2[] corresponds to leaving bit 1.</p><p>Of course, we need to threat the base case here, too. When left + 1 = right, res[left] = cnt[left]. We can keep only one array res[] instead of 3, I explained it this way only for simplicity. Also, there is no need for keeping separate arrays for res[] and cnt[], one can solve all task with only one array. In order to get res[], we simply call solve(0, 2^24).</p><p>Complexity of solution is O(2 ^ 24 * 24). I leave the proof homework, it's almost identical to complexity proof of D1 D "Author solution" (that with building a binary tree).</p><p>For a reference solution, check <a class=\"rated-user user-red\" href=\"/profile/Endagorion\" title=\"Grandmaster Endagorion\">Endagorion</a>'s AC source during contest. </p></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/384\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 225 (Div. 2)</a> </span>\r\n </div>\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/383\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 225 (Div. 1)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-12457-10531\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"12457\",\n blogEntryId: \"10476\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n <div style=\"font-size: 1.1rem;line-height: 11px;\">\r\n <img style=\"vertical-align: middle;\" src=\"//codeforces.org/s/81027/images/blog/tags.png\" title=\"Tags\" alt=\"Tags\"/>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=codeforces\" class=\"tag notice\" style=\"text-decoration: none;\">codeforces</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=225\" class=\"tag notice\" style=\"text-decoration: none;\">225</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=editorial\" class=\"tag notice\" style=\"text-decoration: none;\">editorial</a>\r\n </span>\r\n </div>\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-10531\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+418</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-10531\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/fchirica\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/fchirica\">\n fchirica\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Jan/20/2014 22:18\">10 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/10476#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/10476#comments\">\n 52\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"10547\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (45)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158582\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PAP\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/78534/avatar/d5bcc04085999f83.jpg'/> </a>\n <div><a href=\"/profile/PAP\" title=\"Candidate Master PAP\" class=\"rated-user user-violet\">PAP</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 22:40\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158582\" href=\"?#comment-158582\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158582\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"32\"\r\n data-commentUserId=\"78534\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+32</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158582\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>perfect editorial! thanks a lot!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158582 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158582 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158582\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158591\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/eduardische\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2320/avatar/3ac70493aa90ad2e.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/eduardische\" title=\"International Master eduardische\" class=\"rated-user user-orange\">eduardische</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 22:48\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158591\" href=\"?#comment-158591\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"158591\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"158591\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"10\"\r\n data-commentUserId=\"2320\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+10</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158591\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Just would like to report a typo in 383D contestants' solution: the formula computes D[i+1][j] and not D[i][j]. Thanks for the quick editorial!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158591 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158591 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158591\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158596\" commentParentId=\"158591\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/fchirica\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/57267/avatar/4e655c69b8ad66c2.jpg'/> </a>\n <div><a href=\"/profile/fchirica\" title=\"Candidate Master fchirica\" class=\"rated-user user-violet\">fchirica</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 22:52\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158596\" href=\"?#comment-158596\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-158591\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158596\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"15\"\r\n data-commentUserId=\"57267\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+15</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158596\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks. Fixed. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158596 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158596 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158596\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158598\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Mikester\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/109566/avatar/401b6d72d8f2e768.jpg'/> </a>\n <div><a href=\"/profile/Mikester\" title=\"Master Mikester\" class=\"rated-user user-orange\">Mikester</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 22:54\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158598\" href=\"?#comment-158598\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158598\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"13\"\r\n data-commentUserId=\"109566\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+13</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158598\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>elfus has some of the best rounds on Codeforces, and definitely the best editorials. Congratulations to you and Rares for the round !</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158598 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158598 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158598\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158599\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/iPs\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/144469/avatar/10358ae72910ceac.jpg'/> </a>\n <div><a href=\"/profile/iPs\" title=\"Expert iPs\" class=\"rated-user user-blue\">iPs</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 22:54\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158599\" href=\"?#comment-158599\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158599\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"33\"\r\n data-commentUserId=\"144469\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+33</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158599\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>best editorial I have ever seen in codeforces</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158599 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158599 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158599\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158600\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/bli0042\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/88584/avatar/51c3a9b55a3537fa.jpg'/> </a>\n <div><a href=\"/profile/bli0042\" title=\"Candidate Master bli0042\" class=\"rated-user user-violet\">bli0042</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 22:54\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158600\" href=\"?#comment-158600\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"158600\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"158600\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"88584\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158600\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For Div 2C, if A[i] = A[j] = 0 and we put i before j, won't j lose milk? Or am I misinterpreting the solution?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158600 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158600 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158600\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158601\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/aabs08\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/aabs08\" title=\"Expert aabs08\" class=\"rated-user user-blue\">aabs08</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 22:55\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158601\" href=\"?#comment-158601\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"158601\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"158601\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"9\"\r\n data-commentUserId=\"86699\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+9</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158601\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>One of the best editorials i came across in codeforces :D otherwise the editorial here are really very short and objective.</p><p>Every one here should write editorials like you :) !!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158601 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158601 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158601\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158607\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Xellos\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/69675/avatar/8526bcfc8e687b43.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/Xellos\" title=\"International Grandmaster Xellos\" class=\"rated-user user-red\">Xellos</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 23:03\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158607\" href=\"?#comment-158607\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"158607\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"158607\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"17\"\r\n data-commentUserId=\"69675\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+17</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158607\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Finally a tutorial worth upvoting!</p><p>I didn't really need to think about D. As soon as I saw the constraint on <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/986936bec272878d92f9c6fb0f0ce3c5b118cc0e.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />, I decided to try a DP on (position,sum) — it was a massive hint for me. Well, sometimes it just happens that there's a simple solution, which the author doesn't realize :D. Maybe this could be eliminated by some extensive "problem testing" by random capable people?</p><p>I guess I was also lucky in not trying to solve B. I solved in the order: A (because it's easy), C (because I like it), D (because it's easy) :D</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158607 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158607 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158607\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158610\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Mostafa_36a2\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/137637/avatar/28a01293a2b409.jpg'/> </a>\n <div><a href=\"/profile/Mostafa_36a2\" title=\"Specialist Mostafa_36a2\" class=\"rated-user user-cyan\">Mostafa_36a2</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 23:09\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158610\" href=\"?#comment-158610\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158610\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"-9\"\r\n data-commentUserId=\"137637\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-9</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158610\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I've found a very short solution for Div2 C , by zxz5759209</p> <pre><code>scanf("%d",&n);\n LL cnt=0,sum=0;\n for(int i=1;i<=n;i++)\n {\n scanf("%d",&x);\n cnt+=(LL)x;\n if(!x)sum+=cnt;\n }\n printf("%I64d\\n",sum);\n</code></pre></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158610 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158610 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158610\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158641\" commentParentId=\"158610\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Robert.One\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Robert.One\" title=\"Pupil Robert.One\" class=\"rated-user user-green\">Robert.One</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 01:27\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158641\" href=\"?#comment-158641\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-158610\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158641\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"150202\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158641\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I also had this solution and i got accepted but it took 1 hour to find it during the contest</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158641 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158641 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158641\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158612\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Darek_\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Darek_\" title=\"Specialist Darek_\" class=\"rated-user user-cyan\">Darek_</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 23:12\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158612\" href=\"?#comment-158612\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158612\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"152123\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158612\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks for an informative editorial.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158612 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158612 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158612\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158618\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Mostafa_36a2\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/137637/avatar/28a01293a2b409.jpg'/> </a>\n <div><a href=\"/profile/Mostafa_36a2\" title=\"Specialist Mostafa_36a2\" class=\"rated-user user-cyan\">Mostafa_36a2</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 23:25\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158618\" href=\"?#comment-158618\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"158618\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"158618\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"137637\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158618\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Unbelivable solution for Div2,B by Sick_Coder</p> <pre><code>cin >> n >> m >> k;\n cout << m * (m - 1) / 2 << "\\n";\n\n for (1, m, i)\n \tfor (i + 1, m, j)\n \t\tif (!k)\n \t\t\tcout << i << " " << j << "\\n";\n \t\telse\t\n \t\t\tcout << j << " " << i << "\\n";\n</code></pre></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158618 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158618 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158618\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158631\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mugurelionut\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/63702/avatar/45e4d5390c215090.jpg'/> </a>\n <div><a href=\"/profile/mugurelionut\" title=\"International Master mugurelionut\" class=\"rated-user user-orange\">mugurelionut</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 23:57\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158631\" href=\"?#comment-158631\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158631\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"63702\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158631\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>A very good editorial, indeed! (but please don't forget about Div1E) And the problems were really nice. But I think problem B was tougher than it should have been for its amount of points. I've read some comments saying that problem B had too weak pretests (because so many solutions failed the final system tests). I would have to say that my experience with problem B was the exact opposite. I coded two wrong solutions (which failed some pretest or another) before eventually finding and implementing the right solution. So I'd say that problem B had good pretests :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158631 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158631 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158631\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158635\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/MohammadFatafta\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/148405/avatar/4276577919b9713d.jpg'/> </a>\n <div><a href=\"/profile/MohammadFatafta\" title=\"Specialist MohammadFatafta\" class=\"rated-user user-cyan\">MohammadFatafta</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 00:11\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158635\" href=\"?#comment-158635\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158635\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"148405\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158635\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>now this is a real editorial!! thanks guys :D</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158635 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158635 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158635\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158636\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/matrix\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/matrix\" title=\"Master matrix\" class=\"rated-user user-orange\">matrix</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 00:15\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158636\" href=\"?#comment-158636\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"158636\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"158636\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"16572\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158636\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Hi,</p><p>Great and fast editorial with complete details. </p><p>Thanks very much.</p><p>Edit: I think there is a small typo: "It’s not hard to see that answer for a fixed (i1, j1) is left[i1][j1] * value[2 * j1 – sum_of_elements_from_i1]." I guess you meant count[2 * j1 – sum_of_elements_from_i1].</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158636 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158636 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158636\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158637\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Kyuubi\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/83590/avatar/b87432a652bb276.jpg'/> </a>\n <div><a href=\"/profile/Kyuubi\" title=\"Expert Kyuubi\" class=\"rated-user user-blue\">Kyuubi</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 00:18\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158637\" href=\"?#comment-158637\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158637\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"2\"\r\n data-commentUserId=\"83590\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+2</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158637\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Best Editorials I have seen on codeforces yet! :D</p><p>For Propagating tree, how do we keep track of alternating levels in the arrays we created using DFS ? </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158637 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158637 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158637\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158640\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/k_____k\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/60285/avatar/422359e1ae9d666c.jpg'/> </a>\n <div><a href=\"/profile/k_____k\" title=\"Expert k_____k\" class=\"rated-user user-blue\">k_____k</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 01:07\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158640\" href=\"?#comment-158640\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158640\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"2\"\r\n data-commentUserId=\"60285\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+2</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158640\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Best Editorials Ever ! #thanks to the authors, for posting alternative solutions of contestants also. Great start in 2014. #Looking Forward.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158640 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158640 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158640\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158658\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/sillycross\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/41652/avatar/58966d0c793c6394.jpg'/> </a>\n <div><a href=\"/profile/sillycross\" title=\"Grandmaster sillycross\" class=\"rated-user user-red\">sillycross</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 07:49\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158658\" href=\"?#comment-158658\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158658\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"9\"\r\n data-commentUserId=\"41652\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+9</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158658\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Div1 E can be solved in O(2^24*24) or O(2^24+2^12*n)..</p><p>O(2^24*24): dp[i][s] means the sum of all contributions of subset s where all digits are same as s except the last i digits.. </p><p>O(2^24+2^12*n): the length of word is only 3. We divide the 24 letters in half, calculate the answer for all first 12 letters and all last 12 letters and merge them with brute-force. This can be solved in O(2^24). Then we subtract the words that are counted twice: these words are words that have 2 letters in first half and 1 in second half, or 2 in second half and 1 in first half. Let's consider the first case: for each subset of first 12 letters we check each word whether it has exactly 2 letters in this half, if so, we can say all masks in another half that contains the third letter need to be subtracted by 1. This can be solved in 2^12*(2^12+n). Same algorithm can be used to solve the second case. Although this algorithm runs slower than O(2^24*24) bcuz of its larger constant... </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158658 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158658 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158658\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158663\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/VeniVidiVici\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/VeniVidiVici\" title=\"Candidate Master VeniVidiVici\" class=\"rated-user user-violet\">VeniVidiVici</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 09:39\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158663\" href=\"?#comment-158663\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158663\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"149163\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158663\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Very nice editorial! Disappointed in Div 2B though, really expected the "real" problem rather than just insertion sort but that's what you get for not reading carefully ;)</p><p>However, does anyone have an accepted solution that is "real" (e.g. finds the minimum number of operations necessary and prints such a solution)? I was close but my computer died during contest and I haven't tried so much since (of course you can do O((mn)^2) easily but this is way too slow, there should be a O(n*m^2) solution but again my computer was unable to operate). My approach was to make 2-D boolean array to check if a swap is necessary, but I'm not sure if order of operations will end up being a big problem.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158663 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158663 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158663\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158685\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/LegendaryGrandmaster\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/142091/avatar/a3a5a4b5c26ac419.jpg'/> </a>\n <div><a href=\"/profile/LegendaryGrandmaster\" title=\"Specialist LegendaryGrandmaster\" class=\"rated-user user-cyan\">LegendaryGrandmaster</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 14:34\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158685\" href=\"?#comment-158685\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158685\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"142091\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158685\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>One of the best codeforces editorials ever! Thanks!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158685 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158685 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158685\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158687\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/BENYAM1N\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/84938/avatar/d2ae2657d8898e38.jpg'/> </a>\n <div><a href=\"/profile/BENYAM1N\" title=\"Master BENYAM1N\" class=\"rated-user user-orange\">BENYAM1N</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 15:24\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158687\" href=\"?#comment-158687\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"158687\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"158687\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"84938\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158687\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks a lot. very good contest and good editorial too!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158687 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158687 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158687\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158689\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/JuanMata\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/82548/avatar/a7d69af7b441c6d7.jpg'/> </a>\n <div><a href=\"/profile/JuanMata\" title=\"Expert JuanMata\" class=\"rated-user user-blue\">JuanMata</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 15:47\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158689\" href=\"?#comment-158689\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158689\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"82548\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158689\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>this is one of the best editorials on CF ever!!!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158689 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158689 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158689\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158700\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Vicfred\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/76941/avatar/d067b7433ec39337.jpg'/> </a>\n <div><a href=\"/profile/Vicfred\" title=\"Pupil Vicfred\" class=\"rated-user user-green\">Vicfred</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 16:25\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158700\" href=\"?#comment-158700\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158700\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"11\"\r\n data-commentUserId=\"76941\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+11</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158700\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>The best editorial I've read in a while here, thanks.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158700 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158700 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158700\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158727\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/beecoder\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/beecoder\" title=\"Pupil beecoder\" class=\"rated-user user-green\">beecoder</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 21:13\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158727\" href=\"?#comment-158727\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158727\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"89551\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158727\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Hi, The way I print answers for 'Coder Problem' is as follows. This takes 124 ms. is there a way to print the answers faster ? </p> <pre><code> \tfor (int i = 0 ; i < number ; i ++ ) { \n \t\tfor (int k = 0 ; k < number ; k ++ ) { \n \t\t\tif (flag) {\n \t\t\t\tif ( k % 2 == 1) out.print('.');\n \t\t\t\tif( k% 2 == 0 ) out.print('C');\n \t\t\t} else {\n \t\t\tif ( k % 2 == 1) out.print('C');\n \t\t\tif( k% 2 == 0 ) out.print('.');\t\n \t\t\t}\n \t\t}\n \t\tif (flag) flag = false;\n \t\telse flag = true;\n \t\tout.print("\\n");\n \t}\n \n</code></pre></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158727 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158727 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158727\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158742\" commentParentId=\"158727\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Mostafa_36a2\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/137637/avatar/28a01293a2b409.jpg'/> </a>\n <div><a href=\"/profile/Mostafa_36a2\" title=\"Specialist Mostafa_36a2\" class=\"rated-user user-cyan\">Mostafa_36a2</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/22/2014 14:00\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158742\" href=\"?#comment-158742\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-158727\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158742\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"137637\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158742\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>As the line contains k characters , and every odd lines are identical , also the even ones,</p><p>you can build 2 strings [C.C.C.C] and [.C.C.C.] and print them alternately </p><p>[In my opinion Java is slow language any way ]</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158742 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158742 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158742\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158752\" commentParentId=\"158727\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/t_thirupathi\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/146179/avatar/98c28348196ce4ca.jpg'/> </a>\n <div><a href=\"/profile/t_thirupathi\" title=\"Specialist t_thirupathi\" class=\"rated-user user-cyan\">t_thirupathi</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/22/2014 18:19\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158752\" href=\"?#comment-158752\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-158727\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158752\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"146179\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158752\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Modulo operations are time consuming.</p><p>To check if a number <code>n</code> is odd, you could use <code>if (n & 1)</code></p> <pre><code>for (int i = 0; i < n; i++) {\n for (int j = 0; j < n; j++)\n if ((i + j) & 1)\n out.print('.');\n else \n out.print('C');\n out.print('\\n');\n}\n</code></pre></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158752 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158752 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158752\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158745\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/JuanMata\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/82548/avatar/a7d69af7b441c6d7.jpg'/> </a>\n <div><a href=\"/profile/JuanMata\" title=\"Expert JuanMata\" class=\"rated-user user-blue\">JuanMata</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/22/2014 14:49\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158745\" href=\"?#comment-158745\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"158745\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"158745\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"82548\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158745\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>i think there is a small bug in the <a href=\"http://pastie.org/8651824\">pastie link</a> u posted for the solution of Div1 C problem.</p><p>i submitted almost exact copy of it (<a href=\"/contest/383/submission/5769615\" title=\"Submission 5769615 by JuanMata\">5769615</a>), but got WA#6. then i found the bug, corrected it and resubmitted (<a href=\"/contest/383/submission/5769890\" title=\"Submission 5769890 by JuanMata\">5769890</a>) and got AC.</p><p>referring to my two submissions, corrections in line <strong>68</strong> (last statement of <strong>dfs</strong>) and line <strong>109</strong> (the second call to <strong>update</strong>).</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158745 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158745 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158745\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"615836\" commentParentId=\"158745\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/adityakr007\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/adityakr007\" title=\"Expert adityakr007\" class=\"rated-user user-blue\">adityakr007</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/05/2020 18:54\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-615836\" href=\"?#comment-615836\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-158745\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"615836\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"866209\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-615836\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can you explain what exactly have you done in your submission (<a href=\"/contest/383/submission/5769890\" title=\"Submission 5769890 by JuanMata\">5769890</a>) for this problem?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-615836 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-615836 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-615836\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"629531\" commentParentId=\"615836\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/JuanMata\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/82548/avatar/a7d69af7b441c6d7.jpg'/> </a>\n <div><a href=\"/profile/JuanMata\" title=\"Expert JuanMata\" class=\"rated-user user-blue\">JuanMata</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/25/2020 18:14\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-629531\" href=\"?#comment-629531\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-615836\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"629531\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"82548\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-629531\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>sorry bro i've forgotten ... that was over 6yrs ago now!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-629531 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-629531 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-629531\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158751\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/TempuX\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/30820/avatar/c50adc243ea4e2fa.jpg'/> </a>\n <div><a href=\"/profile/TempuX\" title=\"Specialist TempuX\" class=\"rated-user user-cyan\">TempuX</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/22/2014 17:07\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158751\" href=\"?#comment-158751\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158751\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"30820\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158751\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Hi, I tried to implement the Volcano problem in the way explained in the editorial but I'm getting TLE. Here is my code <a href=\"//codeforces.com/contest/384/submission/5770818\">submission</a> What am I doing wrong ? Thanks anyway.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158751 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158751 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158751\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158811\" commentParentId=\"158751\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/TempuX\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/30820/avatar/c50adc243ea4e2fa.jpg'/> </a>\n <div><a href=\"/profile/TempuX\" title=\"Specialist TempuX\" class=\"rated-user user-cyan\">TempuX</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/23/2014 17:29\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158811\" href=\"?#comment-158811\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-158751\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158811\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"30820\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158811\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Turns out my binary search is causing the problem and I don't see what is wrong with it... I would appreciate any ideas.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158811 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158811 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158811\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159025\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/bboy_drain\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/76710/avatar/e0feb3aa135911d4.jpg'/> </a>\n <div><a href=\"/profile/bboy_drain\" title=\"Expert bboy_drain\" class=\"rated-user user-blue\">bboy_drain</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/25/2014 01:34\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159025\" href=\"?#comment-159025\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159025\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"76710\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159025\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Wow! This really helped me a lot! Very detailed explanations!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159025 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159025 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159025\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159092\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/AlexandruValeanu\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/131651/avatar/1c7d989c45052941.jpg'/> </a>\n <div><a href=\"/profile/AlexandruValeanu\" title=\"Candidate Master AlexandruValeanu\" class=\"rated-user user-violet\">AlexandruValeanu</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/25/2014 21:27\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159092\" href=\"?#comment-159092\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159092\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"131651\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159092\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>It was by far your best round on Codeforces, <a class=\"rated-user user-blue\" href=\"/profile/fchirica\" title=\"Expert fchirica\">fchirica</a>. The problems were great, very different one from the other and some of them didn't require any algorithmic skills at all. Good job!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159092 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159092 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159092\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159261\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lawsonh\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/lawsonh\" title=\"Expert lawsonh\" class=\"rated-user user-blue\">lawsonh</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/28/2014 06:33\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159261\" href=\"?#comment-159261\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"159261\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"159261\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"55047\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159261\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>for div1 383C should end[5] = 7? edit: nvm drew the tree wrong</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159261 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159261 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159261\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159474\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/tiagonapoli\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/150060/avatar/6615fcab66b23361.jpg'/> </a>\n <div><a href=\"/profile/tiagonapoli\" title=\"Candidate Master tiagonapoli\" class=\"rated-user user-violet\">tiagonapoli</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/30/2014 22:28\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159474\" href=\"?#comment-159474\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159474\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"150060\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159474\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Great Editorial! Thanks so much, i've learned a lot!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159474 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159474 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159474\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159707\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lchf\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/60496/avatar/e9939e755252ec16.jpg'/> </a>\n <div><a href=\"/profile/lchf\" title=\"Candidate Master lchf\" class=\"rated-user user-violet\">lchf</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/02/2014 17:28\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159707\" href=\"?#comment-159707\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159707\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"60496\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159707\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Amazing solution by Endagorion.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159707 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159707 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159707\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"177400\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/sourabh912\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/57335/avatar/bf83b9340e3cbb17.jpg'/> </a>\n <div><a href=\"/profile/sourabh912\" title=\"Specialist sourabh912\" class=\"rated-user user-cyan\">sourabh912</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/12/2014 20:39\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-177400\" href=\"?#comment-177400\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"177400\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"57335\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-177400\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In Div 1C problem, I could not understand how it can be solved using single fenwick tree from the solution link in the editorial. Can anyone please help.</p><p>Thanks</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-177400 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-177400 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-177400\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"291157\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/l_Love_KFC\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/258117/avatar/bbaec3ce1613f5bd.jpg'/> </a>\n <div><a href=\"/profile/l_Love_KFC\" title=\"Expert l_Love_KFC\" class=\"rated-user user-blue\">l_Love_KFC</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Apr/29/2016 08:23\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-291157\" href=\"?#comment-291157\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"291157\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"258117\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-291157\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In Div.1 A I didn't catch the point that in 1st, quote : "If we put i before j, no additional cost will be added. Since j is in right of i and i only adds cost when it finds elements in left of i, j won’t be affected when processing i." Won't we lose milk if we put firstly i, in case of that j sees that and loses milk? Or am I misunderstanding the task? </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-291157 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-291157 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-291157\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"309434\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/haleyk100198\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/416324/avatar/f2d97d505af17e9d.jpg'/> </a>\n <div><a href=\"/profile/haleyk100198\" title=\"Candidate Master haleyk100198\" class=\"rated-user user-violet\">haleyk100198</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/11/2016 06:32\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-309434\" href=\"?#comment-309434\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"309434\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"416324\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-309434\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I wonder how the problem Div1C can be converted to a segment tree lazy propagation implementation question, for trees like (1-2 2-3 3-4 4-5 .... 9999-E4) how can we achieve O(log N) update time?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-309434 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-309434 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-309434\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"310847\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/my_new_handle\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/233736/avatar/24128c61b65e3262.jpg'/> </a>\n <div><a href=\"/profile/my_new_handle\" title=\"Candidate Master my_new_handle\" class=\"rated-user user-violet\">my_new_handle</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/20/2016 14:49\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-310847\" href=\"?#comment-310847\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"310847\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"233736\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-310847\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>а зачем в таске б массив он влияет как-то?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-310847 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-310847 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-310847\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"332763\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/rhezo\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/305605/avatar/aa59e9c2ec688c6a.jpg'/> </a>\n <div><a href=\"/profile/rhezo\" title=\"Candidate Master rhezo\" class=\"rated-user user-violet\">rhezo</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Dec/24/2016 07:56\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-332763\" href=\"?#comment-332763\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"332763\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"305605\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-332763\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I'm getting Runtime Error on test 44 in <a href=\"//codeforces.com/problemset/problem/383/C\">Propogating Tree</a>. </p><p>This is because of stack overflow right? That test has N = 2e5 and for a straight chain of nodes, I'll get a runtime error with a recursive DFS right? What to do in such cases? </p><p>I can write an iterative DFS, but I do HLD recursively too and I'm not quite sure if I can write an iterative HLD. </p><p>Can anyone tell me what to do in such cases? I'm assuming that I got the runtime error due to stackoverflow from DFS.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-332763 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-332763 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-332763\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"346070\" commentParentId=\"332763\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/yinanzhu\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/520731/avatar/d61a58bf5df54146.jpg'/> </a>\n <div><a href=\"/profile/yinanzhu\" title=\"Expert yinanzhu\" class=\"rated-user user-blue\">yinanzhu</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/26/2017 07:18\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-346070\" href=\"?#comment-346070\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-332763\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"346070\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"520731\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-346070\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I used recursive dfs and passed all test case. Test 44 cost 1.5 s</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-346070 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-346070 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-346070\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"387028\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/blue__legend\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/blue__legend\" title=\"Expert blue__legend\" class=\"rated-user user-blue\">blue__legend</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/23/2017 07:16\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-387028\" href=\"?#comment-387028\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"387028\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"284949\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-387028\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>How to solve DIV 1 C using one fenwick or segment tree. The code link given in editorial is not working.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-387028 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-387028 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-387028\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"757423\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Ausmosian\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Ausmosian\" title=\"Expert Ausmosian\" class=\"rated-user user-blue\">Ausmosian</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/05/2021 15:05\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-757423\" href=\"?#comment-757423\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"757423\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"727283\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-757423\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>[<a href=\"https://codeforces.com/contest/383/problem/C\">384E — Propagating tree</a>] Can also be solved using Square Root Decomposition. <a href=\"https://codeforces.com/contest/383/submission/106526543\">Submission</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-757423 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-757423 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-757423\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"838255\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/3hill\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1621900/avatar/478297db63bad207.jpg'/> </a>\n <div><a href=\"/profile/3hill\" title=\"Expert 3hill\" class=\"rated-user user-blue\">3hill</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/11/2021 17:02\">2 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-838255\" href=\"?#comment-838255\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"838255\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1621900\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-838255\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I am Getting MLE on TC-53<br />Can someone review my code and figure out the issue ,Thanks</p> <ul> <li><a href=\"https://codeforces.com/contest/383/problem/C\">Problem</a></li> <li><a href=\"https://codeforces.com/contest/383/submission/128510633\">My code</a></li> </ul></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-838255 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-838255 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-838255\">\r\n </ul>\r\n</div>\r\n <br/>\r\n\r\n<div id=\"editBox-10547\" style=\"width:50em;display:none;\">\r\n <div class=\"previewBody\" style=\"border: 1px solid #d4d4d4; margin-bottom: 0.5em; padding: 0.25em; display:none;\"> </div>\r\n <div style=\"width: 1px\"> </div>\r\n <div class=\"commentLocale\" style=\"position: relative; top: 0.5em;left:4px;display: none;\">\r\n <input type=\"radio\" name=\"locale\" value=\"en\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In English</span>\r\n <input style=\"margin-left:1em\" type=\"radio\" name=\"locale\" value=\"ru\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In Russian</span>\r\n </div>\r\n <textarea data-drafts-id=\"CommentReplyFrame\" class=\"wysiwyg\" name=\"editContent\" rows=\"20\" style=\"width:99%;\"></textarea>\r\n <div class=\"error error__content\"></div>\r\n <div style=\"text-align:center;\">\r\n <input type=\"button\" name=\"preview\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Preview\"/>\r\n <input type=\"button\" name=\"save\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Save\"/>\r\n </div>\r\n</div>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n\r\nvar firstPreview10547 = true;\r\nvar lastPreviewContent10547 = '';\r\n\r\nif (!window.moveCommentRevision) {\r\n moveCommentRevision = function(e, dir) {\r\n var p = e.parent();\r\n var revisionCount = parseInt(p.attr(\"revisionCount\"));\r\n var revision = parseInt(p.attr(\"revision\"));\r\n var next = revision + dir;\r\n var commentId = p.attr(\"commentId\");\r\n if (next >= 1 && next <= revisionCount) {\r\n $.post(\r\n \"/data/comment-data\",\r\n {action: \"revision\", commentId: commentId, revision: next},\r\n function(json) {\r\n if (json.success == \"true\") {\r\n var parentDiv = e;\r\n\r\n while (parentDiv !== null && (parentDiv[0].nodeName.toLowerCase() !== \"td\" || !parentDiv.hasClass(\"right\"))) {\r\n parentDiv = parentDiv.parent();\r\n }\r\n\r\n if (parentDiv === null) {\r\n return;\r\n }\r\n\r\n parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\").html(json.content);\r\n Codeforces.setupSpoilers(parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\"));\r\n p.attr(\"revision\", next);\r\n p.find(\"span.revision\").text(next);\r\n if (next == 1) {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"visible\");\r\n }\r\n if (next == revisionCount) {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"visible\");\r\n }\r\n\r\n window.updateTypography();\r\n MathJax.Hub.Typeset();\r\n } else {\r\n alert(e.error);\r\n }\r\n },\r\n \"json\"\r\n );\r\n }\r\n };\r\n}\r\n\r\n$(\"div[commentableId=10547] a.leftRevision\").click(function () {\r\n window.moveCommentRevision($(this), -1);\r\n return false;\r\n});\r\n\r\n$(\"div[commentableId=10547] a.rightRevision\").click(function () {\r\n window.moveCommentRevision($(this), +1);\r\n return false;\r\n});\r\n\r\n\r\n\r\n });\n </script>\n\r\n\r\n <script src=\"//codeforces.org/s/81027/js/swfobject-2.2.min.js\" type=\"text/javascript\"></script>\n <script src=\"//codeforces.org/s/81027/js/ftaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n if (window.evercookie) {\n var ec = new evercookie({\n history: false,\n silverlight: false,\n baseurl: '',\n asseturi: '/assets',\n phpuri: '/2fdcd78',\n pngPath: '/eps',\n etagPath: '/ees',\n cachePath: '/ecs'\n });\n\n var randomNumber = function () {\n return Math.random().toString(36).substr(2);\n };\n\n var randomToken = function () {\n return (randomNumber() + randomNumber()).substring(0, 18);\n };\n\n window._ftaa = \"\";\n\n ec.get(\"70a7c28f3de\", function (value) {\n window._ftaa = value;\n if (!window._ftaa) {\n window._ftaa = randomToken();\n ec.set(\"70a7c28f3de\", window._ftaa);\n }\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n } else {\n window._ftaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\n <script src=\"//codeforces.org/s/81027/js/bfaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n var fpCallback = function() {\n Fingerprint2.get({}, function(components) {\n window._bfaa = Fingerprint2.x64hash128(components.map(function (pair) { return pair.value }).join(), 31);\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n };\n if (typeof Fingerprint2 !== 'undefined') {\n if (window.requestIdleCallback) {\n requestIdleCallback(fpCallback)\n } else {\n setTimeout(fpCallback, 500)\n }\n } else {\n window._bfaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"a.new-root-comment\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n\r\n $(\".comment-table .reply a\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".vote-for-comment\").mouseover(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").mouseout(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").click(function () {\r\n var vote = $(this);\r\n var commentId = $(this).parent().attr(\"commentid\");\r\n var commentRating = $(this).parent().attr(\"data-commentRating\");\r\n var direction = $(this).attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n $.post(\"/data/comment/vote\", {commentId: commentId, _tta: Codeforces.tta(), vote: direction, commentRating: commentRating}, function(data) {\r\n if (direction != 0 && !ownComment && data[\"success\"] == \"true\") {\r\n vote.parent().find(\".vote-for-comment\").attr(\"voteDirection\", 0);\r\n if (direction == 1)\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n else {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.closest(\".CommentVoteFrame\").find(\".ComplaintFrame\").css(\"display\", \"inline-block\");\r\n }\r\n vote.find(\"img\").attr(\"popacity\", \"1.0\");\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n vote.parent().find(\".commentRating\").html(data[\"commentRating\"]);\r\n }\r\n Codeforces.showMessage(data[\"message\"]);\r\n }, \"json\");\r\n return false;\r\n });\r\n\r\n $(\".negative-comment-vote\").closest(\".comment-table\").addClass(\"comment-bad\");\r\n\r\n $(\".troll-comment-vote\").closest(\".comment\").css(\"display\", \"none\");\r\n\r\n $(\".too-negative-comment-vote\").closest(\".comment-table\").each(function () {\r\n var e = $(this);\r\n e.addClass(\"comment-too-bad\");\r\n var commentId = e.attr(\"commentId\");\r\n $(\"<div class='bad-comment-replacement ttypography'>The comment is hidden because of too negative feedback, click <a href=# class=show-bad-comment-link>here</a> to view it</div>\").appendTo(\r\n e.find(\".right\")\r\n );\r\n e.find(\".comment-content\").hide();\r\n e.find(\".show-bad-comment-link\").click(function () {\r\n e.find(\".comment-content\").show();\r\n e.find(\".bad-comment-replacement\").hide();\r\n return false;\r\n });\r\n });\r\n });\n </script>\n </div>\r\n\r\n <style type=\"text/css\">\r\n .new-comments-box {\r\n padding: 0.5em;\r\n width: 22px;\r\n font-size: 1.3rem;\r\n font-weight: bold !important;\r\n\r\n position: fixed;\r\n top: 40%;\r\n right: 0;\r\n opacity: 0.2;\r\n color: white;\r\n text-align: center;\r\n\r\n border: 1px solid #222;\r\n background-color: #888 !important;\r\n border-radius: 3px;\r\n -moz-border-radius: 3px;\r\n -webkit-border-radius: 3px;\r\n }\r\n\r\n .new-comments-box:hover {\r\n opacity: 1;\r\n }\r\n\r\n .new-comments-box .dir:hover {\r\n background: #3B5998 !important;\r\n cursor: pointer;\r\n }\r\n </style>\r\n\r\n <div class=\"new-comments-box\" data-position=\"outside\" data-index=\"-1\" style=\"display: none;\">\r\n <div class=\"up dir\" title=\"Ctrl+Up\">↑<hr/>\r\n </div>\r\n <div class=\"info\" title=\"New comments\"></div>\r\n <div class=\"down dir\" title=\"Ctrl+Down\">\r\n <hr/>↓\r\n </div>\r\n </div>\r\n\r\n <script>\r\n $(\".show-archived-checkbox\").change(function () {\r\n const checked = $(this).is(\":checked\");\r\n $.post(\"/data/comment-data\", {action: \"setShowArchived\", checked}, function (json) {\r\n if (json[\"success\"] !== \"true\") {\r\n alert(json[\"error\"]);\r\n } else {\r\n if (checked) {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are now displayed\")\r\n } else {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are no longer displayed\")\r\n }\r\n }\r\n });\r\n return false;\r\n });\r\n\r\n function gotoComment(direction) {\r\n var box = $(\".new-comments-box\");\r\n var index = parseInt(box.attr(\"data-index\"));\r\n if (index == -1)\r\n index = 0;\r\n else\r\n index = Math.max(0, Math.min(parseInt(box.find(\".info\").text()) - 1, index + direction));\r\n box.attr(\"data-index\", index);\r\n var comment = $($(\".comment .highlight-blue[commentId]\").get(index));\r\n $('html, body').animate({\r\n 'scrollTop': Math.max(0, comment.offset().top - ($(window).height() - comment.height()) / 2)\r\n });\r\n return false;\r\n }\r\n\r\n $(\".new-comments-box .down\").click(function () {\r\n return gotoComment(1);\r\n });\r\n\r\n $(\".new-comments-box .up\").click(function () {\r\n return gotoComment(-1);\r\n });\r\n\r\n $(document).keydown(function (e) {\r\n var code = (e.keyCode ? e.keyCode : e.which);\r\n if (e.ctrlKey) {\r\n if (code == 38 || code == 40) {\r\n gotoComment(code - 39);\r\n }\r\n }\r\n });\r\n\r\n var newCommentCount = $(\".comment .highlight-blue[commentId]\").length;\r\n if (newCommentCount > 0) {\r\n $(\".new-comments-box .info\").text(newCommentCount);\r\n $(\".new-comments-box\").show();\r\n }\r\n\r\n $('table.comment-table').mouseenter(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").addClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n\r\n $('table.comment-table').mouseleave(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").removeClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n </script>\r\n\r\n\r\n\r\n <script>\r\n function adjustTopicComplainFrames() {\r\n let topicIds = [];\r\n\r\n $(\".has-topic-id\").each(function () {\r\n const $this = $(this);\r\n const topicId = $this.attr(\"topicId\");\r\n if (topicId) {\r\n topicIds.push(topicId);\r\n }\r\n });\r\n\r\n $.post(\"/data/topics\", {\r\n action: \"findComplainableTopicIds\",\r\n topicIds: topicIds.join(\",\")\r\n }, function (json) {\r\n if (json[\"success\"] === \"true\") {\r\n for (const topicId of json[\"complainableTopicIds\"].split(\",\")) {\r\n $(\".has-topic-id[topicId=\" + topicId + \"]\").each(function () {\r\n $(this).find(\".meta .ComplaintFrame\").css(\"display\", \"inline-block\");\r\n });\r\n }\r\n }\r\n }, \"json\");\r\n }\r\n\r\n $(function () {\r\n adjustTopicComplainFrames();\r\n })\r\n </script>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-10531\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 10531, _tta: Codeforces.tta(), topicRevisionId: 36233, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-10531\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 10531, _tta: Codeforces.tta(), topicRevisionId: 36233, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n </div>\r\n </div>\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 22:13:02</span> (h1).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/81027/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/81027/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/81027/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/81027/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-81027.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'81287584a8369d92',t:'MTY5NjcwNTk4Mi42NDcwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"}}},{"rowIdx":1937,"cells":{"problem_id":{"kind":"string","value":"383D"},"contest":{"kind":"string","value":"383"},"problem":{"kind":"string","value":"D"},"lang":{"kind":"string","value":"en"},"problem_title":{"kind":"string","value":"D. Antimatter"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">D. Antimatter</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Iahub accidentally discovered a secret lab. He found there <span class=\"tex-span\"><i>n</i></span> devices ordered in a line, numbered from <span class=\"tex-span\">1</span> to <span class=\"tex-span\"><i>n</i></span> from left to right. Each device <span class=\"tex-span\"><i>i</i></span> <span class=\"tex-span\">(1 ≤ <i>i</i> ≤ <i>n</i>)</span> can create either <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> units of matter or <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> units of antimatter. </p><p>Iahub wants to choose some contiguous subarray of devices in the lab, specify the production mode for each of them (produce matter or antimatter) and finally take a photo of it. However he will be successful only if the amounts of matter and antimatter produced in the selected subarray will be the same (otherwise there would be overflowing matter or antimatter in the photo). </p><p>You are requested to compute the number of different ways Iahub can successful take a photo. A photo is different than another if it represents another subarray, or if at least one device of the subarray is set to produce matter in one of the photos and antimatter in the other one.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains an integer <span class=\"tex-span\"><i>n</i></span> <span class=\"tex-span\">(1 ≤ <i>n</i> ≤ 1000)</span>. The second line contains <span class=\"tex-span\"><i>n</i></span> integers <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub></span>, <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">2</sub></span>, ..., <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>n</i></sub></span> <span class=\"tex-span\">(1 ≤ <i>a</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 1000)</span>.</p><p>The sum <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub> + <i>a</i><sub class=\"lower-index\">2</sub> + ... + <i>a</i><sub class=\"lower-index\"><i>n</i></sub></span> will be less than or equal to <span class=\"tex-span\">10000</span>.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Output a single integer, the number of ways Iahub can take a photo, modulo <span class=\"tex-span\">1000000007</span> (<span class=\"tex-span\">10<sup class=\"upper-index\">9</sup> + 7</span>).</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>4<br/>1 1 1 1<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>12<br/></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>The possible photos are [1+, 2-], [1-, 2+], [2+, 3-], [2-, 3+], [3+, 4-], [3-, 4+], [1+, 2+, 3-, 4-], [1+, 2-, 3+, 4-], [1+, 2-, 3-, 4+], [1-, 2+, 3+, 4-], [1-, 2+, 3-, 4+] and [1-, 2-, 3+, 4+], where \"<span class=\"tex-span\"><i>i</i></span>+\" means that the <span class=\"tex-span\"><i>i</i></span>-th element produces matter, and \"<span class=\"tex-span\"><i>i</i></span>-\" means that the <span class=\"tex-span\"><i>i</i></span>-th element produces antimatter.</p></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"18eba969fbc7b556dc09fd53d391169e\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - D - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"f2f8284d26a4a4d6b4f15082f9e1ab3f212e9edd\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - D - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/73366/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/73366/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/73366/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/73366/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/73366/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/73366/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/73366/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/73366/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/73366/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/73366/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/73366/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/73366/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/73366/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/73366/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/sidebar-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/a037fe51637846d9c7c725713cd840ea/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='18eba969fbc7b556dc09fd53d391169e'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/73366/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/73366/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fcontest%2F383%2Fproblem%2FD%3Flocale%3Den\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"current\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='18eba969fbc7b556dc09fd53d391169e'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:100%;\"><a style=\"color: black\" href=\"/contest/383\">Codeforces Round 225 (Div. 1)</a></th>\n </tr>\n <tr>\n <td class=\"left bottom\" colspan=\"1\"><span class=\"contest-state-phase\">Finished</span></td>\n </tr>\n </tbody>\n </table>\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Practice?\n <div class=\"top-links\">\n </div>\n </div>\n<div>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Want to solve the contest problems after the official contest ends? Just register for practice and you will be able to submit solutions.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"\" method=\"post\"><input type='hidden' name='csrf_token' value='18eba969fbc7b556dc09fd53d391169e'/>\r\n <input type=\"hidden\" name=\"action\" value=\"registerForPractice\"/>\r\n <input type=\"submit\" name=\"submit\" value=\"Register for practice\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div> \r\n</div>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox ContestVirtualFrame borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Virtual participation <i class=\"sidebar-caption-icon las la-angle-down\"></i>\r\n\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\" \"\r\n\r\n data-page-url=\"/data/sidebarFrames\"\r\n\r\n>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests.\n\nIf you've seen these problems, a virtual contest is not for you - solve these problems in the archive.\n\nIf you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.\n\nNever use someone else's code, read the tutorials or communicate with other person during a virtual contest.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"/contest/383/virtual\" method=\"get\">\r\n <input type=\"submit\" name=\"submit\" value=\"Start virtual contest\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div>\r\n</div>\r\n <script>\r\n $(function () {\r\n $(\".ContestVirtualFrame .sidebar-caption-icon\").click(function() {\r\n $(this).toggleClass(\"la-angle-down la-angle-right\");\r\n const $target = $(this).parent().next();\r\n $target.toggle();\r\n const dataPageUrl = $target.attr(\"data-page-url\");\r\n const collapsed = $(this).hasClass(\"la-angle-right\");\r\n const params = {\r\n action: \"setCollapsed\",\r\n sidebarFrameSimpleClassName: \"ContestVirtualFrame\",\r\n collapsed\r\n };\r\n $.each($target[0].attributes, function(i, a) {\r\n const name = a.name;\r\n if (name.startsWith(\"data-extra-key-\")) {\r\n const key = a.value;\r\n const keyIndex = parseInt(name.substring(\"data-extra-key-\".length));\r\n const value = $target.attr(\"data-extra-value-\" + keyIndex);\r\n params[key] = value;\r\n }\r\n });\r\n $.post(dataPageUrl, params, function (result) {\r\n if (result[\"success\"] !== \"true\") {\r\n Codeforces.showMessage(\"Failed to save collapsed state.\");\r\n }\r\n }, \"json\");\r\n return false;\r\n });\r\n })\r\n </script>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Problem tags\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Dynamic programming\">\r\n dp\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Difficulty\">\r\n *2300\r\n</span>\r\n </div>\n <div style=\"clear:both;text-align:right;font-size:1.1rem;\">\r\n <span title=\"Please login into the Codeforces\" class=\"notice\">No tag edit access</span>\r\n </div>\r\n</div>\r\n </div>\n\r\n<form id=\"addTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='18eba969fbc7b556dc09fd53d391169e'/>\r\n <input name=\"action\" type=\"hidden\" value=\"addTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"5725\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<form id=\"removeTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='18eba969fbc7b556dc09fd53d391169e'/>\r\n <input name=\"action\" type=\"hidden\" value=\"removeTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"5725\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<script type=\"text/javascript\">\r\n $(\".tag-box img\").click(function () {\r\n var tagName = $(this).attr(\"value\");\r\n Codeforces.confirm(\"Are you sure you want to remove this tag?\", function () {\r\n $(\"#removeTagForm input[name=tagName]\").val(tagName);\r\n $(\"#removeTagForm\").submit();\r\n }, function () {\r\n }, \"Yes\", \"No\");\r\n });\r\n\r\n $(\"#addTagLink\").click(function () {\r\n $(this).hide();\r\n $(\"#addTagLabel\").show();\r\n return false;\r\n });\r\n\r\n $(\"#addTagSelect\").change(function () {\r\n var tagName = $(this).val();\r\n if (tagName === \"\") {\r\n $(\"#addTagLabel\").hide();\r\n $(\"#addTagLink\").show();\r\n } else {\r\n $(\"#addTagForm input[name=tagName]\").val(tagName);\r\n $(\"#addTagForm\").submit();\r\n }\r\n });\r\n</script>\r\n\r\n<style type=\"text/css\">\r\n#new-resource-form tr td {\r\npadding-top: 0.5em;\r\n}\r\n#new-resource-form input:not([type=\"submit\"]) {\r\nfont-size: 0.8em;\r\n}\r\n#new-resource-form select {\r\nfont-size: 0.8em;\r\n}\r\n.new-resource-error {\r\nfont-size: 0.8em;\r\n}\r\n.resource-locale {\r\ncolor: #666;\r\nfont-family: Consolas, \"Andale Mono WT\", \"Andale Mono\", \"Lucida Console\", \"Lucida Sans Typewriter\", \"DejaVu Sans Mono\", \"Bitstream Vera Sans Mono\", \"Liberation Mono\", \"Nimbus Mono L\", Monaco, \"Courier New\", Courier, monospace;\r\n}\r\n</style>\r\n<div class=\"roundbox sidebox sidebar-menu borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Contest materials\n<div class=\"top-links\">\n</div>\n</div>\n<ul>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/10448\" title=\"Codeforces Round #225\" target=\"_blank\">Codeforces Round #225</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"2166:2167\" resourceName=\"Announcement\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n<li>\r\n<span>\r\n<a href=\"https://codeforces.com/blog/entry/10476\" title=\"Tutorial\" target=\"_blank\">Tutorial <span class=\"resource-locale\">(en)</span></a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"2170\" resourceName=\"Tutorial\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n</ul>\r\n</div></div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li class=\"current selectedLava\"><a\r\n href=\"/contest/383\">Problems</a></li>\r\n <li><a\r\n href=\"/contest/383/submit\">Submit Code</a></li>\r\n <li><a\r\n href=\"/contest/383/my\">My Submissions</a></li>\r\n <li><a\r\n href=\"/contest/383/status\">Status</a></li>\r\n <li><a\r\n href=\"/contest/383/hacks\">Hacks</a></li>\r\n <li><a\r\n href=\"/contest/383/room/1\">Room</a></li>\r\n <li><a\r\n href=\"/contest/383/standings\">Standings</a></li>\r\n <li><a\r\n href=\"/contest/383/customtest\">Custom Invocation</a></li>\r\n</ul>\r\n</div>\n\r\n <style>\r\n #facebox .content:has(.diff-popup) {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n }\r\n\r\n .testCaseMarker {\r\n position: absolute;\r\n font-weight: bold;\r\n font-size: 1rem;\r\n }\r\n\r\n .diff-popup {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n display: none;\r\n overflow: auto;\r\n }\r\n\r\n .input-output-copier {\r\n font-size: 1.2rem;\r\n float: right;\r\n color: #888 !important;\r\n cursor: pointer;\r\n border: 1px solid rgb(185, 185, 185);\r\n padding: 3px;\r\n margin: 1px;\r\n line-height: 1.1rem;\r\n text-transform: none;\r\n }\r\n\r\n .input-output-copier:hover {\r\n background-color: #def;\r\n }\r\n\r\n .test-explanation textarea {\r\n width: 100%;\r\n height: 1.5em;\r\n }\r\n\r\n .pending-submission-message {\r\n color: darkorange !important;\r\n }\r\n </style>\r\n <script>\r\n const OPENING_SPACE = String.fromCharCode(1001);\r\n const CLOSING_SPACE = String.fromCharCode(1002);\r\n\r\n const nodeToText = function (node, pre) {\r\n let result = [];\r\n\r\n if (node.tagName === \"SCRIPT\" || node.tagName === \"math\"\r\n || (node.classList && node.classList.contains(\"input-output-copier\")))\r\n return [];\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(OPENING_SPACE);\r\n }\r\n\r\n if (node.nodeType === Node.TEXT_NODE) {\r\n let s = node.textContent;\r\n if (!pre) {\r\n s = s.replace(/\\s+/g, \" \");\r\n }\r\n if (s.length > 0) {\r\n result.push(s);\r\n }\r\n }\r\n\r\n if (pre && node.tagName === \"BR\") {\r\n result.push(\"\\n\");\r\n }\r\n\r\n node.childNodes.forEach(function (child) {\r\n result.push(nodeToText(child, node.tagName === \"PRE\").join(\"\"));\r\n });\r\n\r\n if (node.tagName === \"DIV\"\r\n || node.tagName === \"P\"\r\n || node.tagName === \"PRE\"\r\n || node.tagName === \"UL\"\r\n || node.tagName === \"LI\"\r\n ) {\r\n result.push(\"\\n\");\r\n }\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(CLOSING_SPACE);\r\n }\r\n\r\n return result;\r\n }\r\n\r\n const isSpecial = function (c) {\r\n return c === ',' || c === '.' || c === ';' || c === ')' || c === ' ';\r\n }\r\n\r\n const convertStatementToText = function(statmentNode) {\r\n const text = nodeToText(statmentNode, false).join(\"\").replace(/ +/g, \" \").replace(/\\n\\n+/g, \"\\n\\n\");\r\n let result = [];\r\n for (let i = 0; i < text.length; i++) {\r\n const c = text.charAt(i);\r\n if (c === OPENING_SPACE) {\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"D\" data-uuid=\"ps_4fe76b9526e03c2912da0d83baf2694f700522cd\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">D. Antimatter</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Iahub accidentally discovered a secret lab. He found there <span class=\"tex-span\"><i>n</i></span> devices ordered in a line, numbered from <span class=\"tex-span\">1</span> to <span class=\"tex-span\"><i>n</i></span> from left to right. Each device <span class=\"tex-span\"><i>i</i></span> <span class=\"tex-span\">(1 ≤ <i>i</i> ≤ <i>n</i>)</span> can create either <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> units of matter or <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> units of antimatter. </p><p>Iahub wants to choose some contiguous subarray of devices in the lab, specify the production mode for each of them (produce matter or antimatter) and finally take a photo of it. However he will be successful only if the amounts of matter and antimatter produced in the selected subarray will be the same (otherwise there would be overflowing matter or antimatter in the photo). </p><p>You are requested to compute the number of different ways Iahub can successful take a photo. A photo is different than another if it represents another subarray, or if at least one device of the subarray is set to produce matter in one of the photos and antimatter in the other one.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains an integer <span class=\"tex-span\"><i>n</i></span> <span class=\"tex-span\">(1 ≤ <i>n</i> ≤ 1000)</span>. The second line contains <span class=\"tex-span\"><i>n</i></span> integers <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub></span>, <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">2</sub></span>, ..., <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>n</i></sub></span> <span class=\"tex-span\">(1 ≤ <i>a</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 1000)</span>.</p><p>The sum <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub> + <i>a</i><sub class=\"lower-index\">2</sub> + ... + <i>a</i><sub class=\"lower-index\"><i>n</i></sub></span> will be less than or equal to <span class=\"tex-span\">10000</span>.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Output a single integer, the number of ways Iahub can take a photo, modulo <span class=\"tex-span\">1000000007</span> (<span class=\"tex-span\">10<sup class=\"upper-index\">9</sup> + 7</span>).</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>4<br />1 1 1 1<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>12<br /></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>The possible photos are [1+, 2-], [1-, 2+], [2+, 3-], [2-, 3+], [3+, 4-], [3-, 4+], [1+, 2+, 3-, 4-], [1+, 2-, 3+, 4-], [1+, 2-, 3-, 4+], [1-, 2+, 3+, 4-], [1-, 2+, 3-, 4+] and [1-, 2-, 3+, 4+], where "<span class=\"tex-span\"><i>i</i></span>+" means that the <span class=\"tex-span\"><i>i</i></span>-th element produces matter, and "<span class=\"tex-span\"><i>i</i></span>-" means that the <span class=\"tex-span\"><i>i</i></span>-th element produces antimatter.</p></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=D]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== statementText) {\r\n $problem.find(\".diff-notifier\").show();\r\n\r\n $problem.find(\".diff-notifier-close\").click(function() {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n $problem.find(\".diff-notifier\").hide();\r\n });\r\n\r\n $problem.find(\"a.view-changes\").click(function() {\r\n $.post(\"/data/diff\", {action: \"getDiff\", a: previousStatementText, b: statementText}, function (result) {\r\n if (result[\"success\"] === \"true\") {\r\n Codeforces.facebox(\".diff-popup\", \"//codeforces.org/s/73366\");\r\n $(\"#facebox .diff-popup\").html(result[\"diff\"]);\r\n }\r\n }, \"json\");\r\n });\r\n }\r\n } else {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n }\r\n });\r\n });\r\n </script>\r\n\r\n\r\n<script type=\"text/javascript\">\r\n $(document).ready(function () {\r\n window.changedTests = new Set();\r\n\r\n function endsWith(string, suffix) {\r\n return string.indexOf(suffix, string.length - suffix.length) !== -1;\r\n }\r\n\r\n const inputFileDiv = $(\"div.input-file\");\r\n const inputFile = inputFileDiv.text();\r\n const outputFileDiv = $(\"div.output-file\");\r\n const outputFile = outputFileDiv.text();\r\n\r\n\r\n if (!endsWith(inputFile, \"standard input\")\r\n && !endsWith(inputFile, \"standard input\")) {\r\n inputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n if (!endsWith(outputFile, \"standard output\")\r\n && !endsWith(outputFile, \"standard output\")) {\r\n outputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n const titleDiv = $(\"div.header div.title\");\r\n\r\n\r\n\r\n String.prototype.replaceAll = function (search, replace) {\r\n return this.split(search).join(replace);\r\n };\r\n\r\n $(\".sample-test .title\").each(function () {\r\n const preId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n const cpyId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n\r\n $(this).parent().find(\"pre\").attr(\"id\", preId);\r\n const $copy = $(\"<div title='Copy' data-clipboard-target='#\" + preId + \"' id='\" + cpyId + \"' class='input-output-copier'>Copy</div>\");\r\n $(this).append($copy);\r\n\r\n const clipboard = new Clipboard('#' + cpyId, {\r\n text: function (trigger) {\r\n const pre = document.querySelector('#' + preId);\r\n const lines = pre.querySelectorAll(\".test-example-line\");\r\n return Codeforces.filterClipboardText(pre.innerText, lines.length);\r\n }\r\n });\r\n\r\n const isInput = $(this).parent().hasClass(\"input\");\r\n\r\n clipboard.on('success', function (e) {\r\n if (isInput) {\r\n Codeforces.showMessage(\"The example input has been copied into the clipboard\");\r\n } else {\r\n Codeforces.showMessage(\"The example output has been copied into the clipboard\");\r\n }\r\n e.clearSelection();\r\n });\r\n });\r\n\r\n $(\".test-form-item input\").change(function () {\r\n addPendingSubmissionMessage($($(this).closest(\"form\")), \"You changed the answer, do not forget to submit it if you want to save the changes\");\r\n const index = $(this).closest(\".problemindexholder\").attr(\"problemindex\");\r\n let test = \"\";\r\n $(this).closest(\"form input\").each(function () {\r\n const test_ = $(this).attr(\"name\");\r\n if (test_ && test_.substring(0, 4) === \"test\") {\r\n test = test_;\r\n }\r\n });\r\n if (index.length > 0 && test.length > 0) {\r\n const indexTest = index + \"::\" + test;\r\n window.changedTests.add(indexTest);\r\n }\r\n });\r\n\r\n $(window).on('beforeunload', function () {\r\n if (window.changedTests.size > 0) {\r\n return 'Dialog text here';\r\n }\r\n });\r\n\r\n autosize($('.test-explanation textarea'));\r\n\r\n $(\".test-example-line\").hover(function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n let top = 1E20;\r\n let left = 1E20;\r\n let problem = $(this).closest(\".problemindexholder\");\r\n $(this).closest(\".input\").find(\".\" + clazz).css(\"background-color\", \"#FFFDE7\").each(function() {\r\n top = Math.min(top, $(this).offset().top);\r\n left = Math.min(left, $(this).offset().left);\r\n });\r\n let testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n if (testCaseMarker.length === 0) {\r\n const html = \"<div class=\\\"testCaseMarker testCaseMarker_\" + end + \" notice\\\"></div>\";\r\n problem.append($(html));\r\n testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n }\r\n if (testCaseMarker) {\r\n testCaseMarker.show()\r\n .offset({top, left: left - 20})\r\n .text(end);\r\n }\r\n }\r\n }\r\n });\r\n }, function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n $(\".\" + clazz).css(\"background-color\", \"\");\r\n $(this).closest(\".problemindexholder\").find(\".testCaseMarker_\" + end).hide();\r\n }\r\n }\r\n });\r\n });\r\n\r\n });\r\n</script>\r\n\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 05:38:01</span> (j3).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/73366/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/73366/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/73366/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/73366/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-73366.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'8122c3f9be969d8d',t:'MTY5NjY0NjI4MS4zMTQwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"},"long_tags":{"kind":"string","value":"[\"Dynamic programming\"]"},"short_tags":{"kind":"string","value":"[\"dp\", \"*2300\"]"},"tutorial_link":{"kind":"string","value":"https://codeforces.com/blog/entry/10476"},"tutorial_page":{"kind":"string","value":"\r\n\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"4f4c31ed5807bbee2a02378cf0944c06\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"h1\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Codeforces Round #225 — Editorial - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n \n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Codeforces Round #225 — Editorial - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/81027/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/81027/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/81027/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/81027/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/81027/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/81027/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/81027/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/81027/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/81027/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/81027/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/81027/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/81027/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/81027/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/81027/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/573cedc6b04c15481941f418269f4057/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='4f4c31ed5807bbee2a02378cf0944c06'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/81027/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fblog%2Fentry%2F10476\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='4f4c31ed5807bbee2a02378cf0944c06'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Pay attention\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n <div style=\"text-align:center;border-bottom: 1px solid rgb(185, 185, 185);margin:0 -0.5em 0.5em -0.5em;padding: 0 1em 0.5em 1em;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 1, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:51:58</span><br/><a href=\"/contestRegistration/1876\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n <div style=\"text-align:center;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 2, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:51:58</span><br/><a href=\"/contestRegistration/1877\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n\r\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div>\r\n\r\n\n <div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\n\r\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='4f4c31ed5807bbee2a02378cf0944c06'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n </label>\r\n </div>\r\n <div style=\"padding: 0 1em 1em 1em;text-align:right;\">\r\n <input style=\"height:1.65em;padding:0 0.75em;\" type=\"submit\" value=\"Find\"/>\r\n </div>\r\n </form>\r\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".handleBox\").autocomplete(\"/data/handles\", {\r\n delay: 200,\r\n width: 200,\r\n selectFirst: false,\r\n matchContains: true,\r\n minChars: 3\r\n });\r\n $(\".handleForm\").attr(\"autocomplete\", \"off\").submit(function () {\r\n var link = \"/profile/userHandle\".replace(\r\n \"userHandle\", $(this).find(\".handleBox\").val()\r\n );\r\n window.location = link;\r\n return false;\r\n });\r\n });\n </script>\n\r\n\r\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Recent actions\n <div class=\"top-links\">\n </div>\n </div>\n <div class=\"recent-actions\">\r\n <ul>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/121073\">Meta Hacker Cup 2023 Round 1</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/.Danet\" title=\"Expert .Danet\" class=\"rated-user user-blue\">.Danet</a> →\r\n <a href=\"/blog/entry/121172\">[TLE on pretest1]</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\" class=\"rated-user user-red\">Pyqe</a> →\r\n <a href=\"/blog/entry/121025\">Codeforces Round #902 (Div. 1, Div. 2, based on COMPFEST 15 — Final Round)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pranshu_Pandya\" title=\"Specialist Pranshu_Pandya\" class=\"rated-user user-cyan\">Pranshu_Pandya</a> →\r\n <a href=\"/blog/entry/121171\">An Interesting Tree Problem</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/sszcdjr\" title=\"Master sszcdjr\" class=\"rated-user user-orange\">sszcdjr</a> →\r\n <a href=\"/blog/entry/119859\">Codeforces Round 896 (Div. 1, Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/119880\">It's Happening! Meta Hacker Cup 2023 Schedule</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/DaviddeGea1\" title=\"Expert DaviddeGea1\" class=\"rated-user user-blue\">DaviddeGea1</a> →\r\n <a href=\"/blog/entry/70917\">Number of ways of dividing an array into 2 parts such that sum of each part is > k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bekh\" title=\"Master Bekh\" class=\"rated-user user-orange\">Bekh</a> →\r\n <a href=\"/blog/entry/74245\">Questions and doubts regarding Aliens DP trick</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a> →\r\n <a href=\"/blog/entry/8192\">Codeforces Round #190 — Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/hocky\" title=\"Candidate Master hocky\" class=\"rated-user user-violet\">hocky</a> →\r\n <a href=\"/blog/entry/95323\">FBHC wuining uw Day? Incwease uw stacc size! (ㅅ´ ˘ `)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/liouzhou_101\" title=\"International Master liouzhou_101\" class=\"rated-user user-orange\">liouzhou_101</a> →\r\n <a href=\"/blog/entry/87598\">Editorial of Codeforces Round #700</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/yeon_gist\" title=\"Newbie yeon_gist\" class=\"rated-user user-gray\">yeon_gist</a> →\r\n <a href=\"/blog/entry/121170\">plusMinusPermutation computing error</a>\r\n <img alt=\"Text created or updated\" title=\"Text created or updated\" src=\"//codeforces.org/s/81027/images/icons/x-update-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/altforminuscontribution\" title=\"Newbie altforminuscontribution\" class=\"rated-user user-gray\">altforminuscontribution</a> →\r\n <a href=\"/blog/entry/121162\">My screen get unexpectedly big, what should I do</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/atcoder_official\" title=\"Unrated, atcoder_official\" class=\"rated-user user-black\">atcoder_official</a> →\r\n <a href=\"/blog/entry/121120\">We will hold UNIQUE VISION Programming Contest 2023 Autumn(AtCoder Beginner Contest 323)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/YouStill_DontKnowMeYet\" title=\"Candidate Master YouStill_DontKnowMeYet\" class=\"rated-user user-violet\">YouStill_DontKnowMeYet</a> →\r\n <a href=\"/blog/entry/117659\">[GYM] Al-Baath Collegiate Programming Contest 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/ankancool\" title=\"Expert ankancool\" class=\"rated-user user-blue\">ankancool</a> →\r\n <a href=\"/blog/entry/121136\">Invitation to AstroByte 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/GeZhiyuan\" title=\"Grandmaster GeZhiyuan\" class=\"rated-user user-red\">GeZhiyuan</a> →\r\n <a href=\"/blog/entry/120943\">Codeforces Round 901 (Div. 1, Div. 2) Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a> →\r\n <a href=\"/blog/entry/120772\">PSA: Increase your stack size before the Meta Hacker Cup, here's how</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/dino_merlin\" title=\"Expert dino_merlin\" class=\"rated-user user-blue\">dino_merlin</a> →\r\n <a href=\"/blog/entry/121145\">Intuitive approach for CEOI Kangaroo?</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/icecuber\" title=\"Grandmaster icecuber\" class=\"rated-user user-red\">icecuber</a> →\r\n <a href=\"/blog/entry/70018\">CSES DP section editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bn00b\" title=\"Newbie Bn00b\" class=\"rated-user user-gray\">Bn00b</a> →\r\n <a href=\"/blog/entry/98820\">[FEATURE REQUEST : ATCODER] TOPICS TAGS AND SORTING BY SOLVE COUNT</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a> →\r\n <a href=\"/blog/entry/121163\">AtCoder Regular Contest 166 Announcement</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/windva\" title=\"Grandmaster windva\" class=\"rated-user user-red\">windva</a> →\r\n <a href=\"/blog/entry/120644\">Codeforces Round 899 (Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Misa-Misa\" title=\"Expert Misa-Misa\" class=\"rated-user user-blue\">Misa-Misa</a> →\r\n <a href=\"/blog/entry/121157\">Someone please help me understand this.</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/shivam565\" title=\"Specialist shivam565\" class=\"rated-user user-cyan\">shivam565</a> →\r\n <a href=\"/blog/entry/108348\">Total number of subarrays with sum atmost k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n </ul>\r\n </div>\r\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/recent-actions\">Detailed →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n</div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li><a\r\n href=\"/profile/fchirica\">fchirica</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/fchirica\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/fchirica\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/fchirica\">Submissions</a></li>\r\n <li><a\r\n href=\"/groups/with/fchirica\">Groups</a></li>\r\n <li><a\r\n href=\"/contests/with/fchirica\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/fchirica\">Problemsetting</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/fchirica\" style=\"text-decoration:none;color:black !important;\">fchirica's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"10531\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/10476\"> <p>Codeforces Round #225 — Editorial</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/fchirica\" title=\"Candidate Master fchirica\" class=\"rated-user user-violet\">fchirica</a>,\r\n <span class=\"format-humantime\" title=\"Jan/20/2014 22:18\">10 years ago</span>,\r\n \r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><h1><a href=\"/contest/384/problem/A\" title=\"Codeforces Round 225 (Div. 2)\">384A - Coder</a></h1><p>Usually, when you don’t have any idea how to approach a problem, a good try is to take some small examples.</p><p>So let’s see how it looks for N = 1, 2, 3, 4 and 5. With C I noted the coder and with * I noted an empty cell.</p><p><img alt=\" \" src=\"/predownloaded/8f/89/8f899efd227362957f283123a7927c7c8a300667.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>By now you should note that answer is N ^ 2 / 2 when N is even and (N ^ 2 + 1) / 2 when N is odd. Good. Generally, after you find a possible solution by taking examples, you need to prove it, then you can code it.</p><p>In order to proof it, one needs to do following steps:</p><p>1/ prove you can always build a solution having N ^ 2 / 2 (or (N ^ 2 + 1) / 2) pieces.</p><p>2/ prove that N ^ 2 / 2 (or (N ^ 2 + 1) / 2) is maximal number – no other bigger solution can be obtained.</p><p>For proof 1/ imagine you do coloring like in a chess table.</p><p><img alt=\" \" src=\"/predownloaded/50/12/50120d92bd0cea3d6a434d09ab4754ea20342351.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>The key observation is that by placing all coders on black squares of table, no two coders will attack. Why? Because a piece placed at a black square can attack only a piece placed at a white square. Again, why? Suppose chess table is 1-based. Then, a square (i, j) is black if and only if i + j is even. A piece placed at (i, j) can attack (i + 1, j), (i – 1, j) (i, j + 1) or (i, j – 1). The sum of those cells is i + j + 1 or i + j – 1. But since i + j is even, i + j + 1 and i + j – 1 are odd, hence white cells.</p><p>Depending on parity of N, number of black cells is either N ^ 2 / 2 or (N ^ 2 + 1) / 2. For N even, one can observe that there are equal amount of black and white cells. Total number of cells is N ^ 2, so number of black cells is N ^ 2 / 2. For N odd, number of black cells is number of white cells + 1. We can imaginary add a white cell to the board. Now, number of black cells will be also equal to number of white cells, so answer is (N ^ 2 + 1) / 2.</p><p>2/ Two coders attack each other if they are placed at two adjacent cells, one black and other one white. One needs to prove that adding more than number from 1/ will cause this to happen. If you place a coder at a white cell, you won’t be able to place at least one coder at a black cell, so in best case you don’t win anything by doing this. Hence, it’s optimally to place all coders on same color cells. Since cells colored in black are always more or equal to white ones, it’s always optimally to choose black color. But number from 1/ is the number of cells having black color. Adding one more piece will force you to add it to a white color cell. Now, you’ll have a piece placed at a black colored cell and one placed at an adjacent white colored cell, so two coders will attack. Hence, we can’t place more than number from 1/ pieces.</p><p>Code: <a href=\"http://pastie.org/8651801\">http://pastie.org/8651801</a></p><h1><a href=\"/contest/384/problem/B\" title=\"Codeforces Round 225 (Div. 2)\">384B - Multitasking</a></h1><p>Let’s start by saying when array A[] is sorted:</p><p>1/ is sorted in ascending order when i < j and A[i] <= A[j]. It is NOT sorted when i < j and A[i] > A[j].</p><p>2/ is sorted in descending order when i > j and A[i] <= A[j]. It is NOT sorted when i > j and A[i] > A[j].</p><p>Iahub can choose 2 indices i, j and swap values when A[i] > A[j]. If A[i] <= A[j], he’ll ignore operation. Hence, if he wants to sort all arrays in ascending order, he chooses indices i, j when i < j and perform operation. Otherwise, in all his operations he uses indices i, j such as i > j. A “good” operation is when choosing indices i < j for ascending order sorting and i > j for descending order sorting. By doing only good operations, after an array is sorted, it will stay sorted forever (for a sorted array, all good operations will be ignored).</p><p>From here we get our first idea: use any sorting algorithm you know and sort each array individually. When print swaps done by sorting algorithm chosen, print them as good operations. However, sorting each array individually can cause exceeding M * (M — 1) / 2 operations limit. Another possible solution would be, after you did an operation to an array, to update the operation to all arrays (you printed it, so it counts to M * (M — 1) / 2 operations limit; making it to all arrays will help sometimes and in worst case it won’t change anything). However, you need to code it very careful in order to make this algorithm pass the time limit. Doing this in a contest is not the best idea, especially when implementation could be complicated and you have no guarantee it will pass time limit.</p><p>So what else can we do? We can think out of box. Instead of sorting specific N arrays, you can sort all possible arrays of length M. Find a sequence of good operations such as, anyhow I’d choose an array of size M, it will get sorted ascending / descending.</p><p>I’ll show firstly how to do for ascending sorting. At position 1 it needs to be minimal element. Can we bring minimal element there using good operations? Yes. Just do “1 2” “1 3” “1 4” ... “1 M”. It basically compares element from position 1 to any other element from array. When other element has smaller value, swap is done. After comparing with all M elements, minimal value will be at position 1. By now on I’ll ignore position 1 and move to position 2. Suppose array starts from position 2. It also needs minimal value from array, except value from position 1 (which is no longer in array). Hence doing “2 3” “2 4” “2 5” ... “2 M” is enough, by similar reasons. For a position i, I need minimal value from array, except positions 1, 2, ..., i – 1. I simply do “i i+1” “i i+2” ... “i M-1” “i M”. By arriving at position i, array will be sorted ascending. The algorithm is simply:</p><p>for (int i = 1; i < M; ++i)</p><p>for (int j = i + 1; j <= M; ++j)</p><p>cout << i << “ “ << j << “\\n”;</p><p>This algorithm does exactly M * (M — 1) / 2 moves.</p><p>Can you find out how to sort array in descending order? Try to think yourself, then if you don’t get it read next. At first position of a descending array it needs to be maximal value. Similarly to ascending order, we can do “2 1” “3 1” “4 1” ... “M 1”. When I’m at a position i and I compare its value to value from position 1, doing operation “i 1” checks if A[i] > A[1]. If so, it swaps A[i] and A[1], so position 1 will contain now the maximum value so far. Similarly to logic from ascending order, when I’m at position i, I need maximum value from array except positions 1, 2, ..., i – 1, so I do “i+1 i” “i+2 i” ... “M i”. Algorithm is:</p><p>for (int i = 1; i < M; ++i)</p><p>for (int j = i + 1; j <= M; ++j)</p><p>cout << j << “ “ << i << “\\n”;</p><p>Obviously, this does as well M * (M — 1) / 2 operations worst case. All algorithm is about 10 lines of code, much better than other solution, which requires two manually sorts and also has a chance to exceed TL.</p><p>Code: <a href=\"http://pastie.org/8651809\">http://pastie.org/8651809</a></p><h1><a href=\"/contest/384/problem/C\" title=\"Codeforces Round 225 (Div. 2)\">384C - Milking cows</a></h1><p>A good strategy to approach this problem is to think how optimal ordering should look like. For this, let’s calculate for each 2 different cows i and j if cow i needs to be milked before or after cow j. As we’ll show, having this information will be enough to build optimal ordering. It is enough to consider only cases when i < j, case when i > j is exactly the opposite of case i < j. For formality, I’ll call the optimal ordering permutation and lost milk the cost of permutation.</p><p>So, for an optimal permutation P let’s take 2 numbers i < j and see in which cases i should appear before j in permutation (i is before j if P[pos1] = i, P[pos2] = j and pos1 < pos2; otherwise we’ll call i is after j). We have 4 possible cases:</p><p>1/ A[i] = 0 and A[j] = 0</p><p>If we put i before j, no additional cost will be added. Since j is in right of i and i only adds cost when it finds elements in left of i, j won’t be affected when processing i. When processing j, i will be already deleted so it won’t affect the cost either. Hence, we can put i before j and no cost will be added.</p><p>2/ A[i] = 0 and A[j] = 1</p><p>Here, i and j can appear in arbitrary order in permutation (i can be before or after j). No matter how we choose them, they won’t affect each other and cost will remain the same.</p><p>3/ A[i] = 1 and A[j] = 0</p><p>As well, here i and j can appear in arbitrary order. If we choose i first, j will be in right of it, so cost of permutation will increase by one. If we choose j first, i will be in left of it so cost of permutation will increase as well. No matter what we do, in this case cost of permutation increases by 1.</p><p>4/ A[i] = 1 and A[j] = 1</p><p>Here, i needs to be after j. This adds 0 cost. Taking i before j will add 1 cost to permutation (since j is in right of i).</p><p>Those 4 cases show us how a minimal cost permutation should look. In a permutation like this, only case 3/ contributes to final cost, so we need to count number of indices i, j such as i < j and A[i] = 1 and A[j] = 0 (*). If we show a permutation following all rules exists, task reduces to (*).</p><p>By cases 2/ and 3/ it follows that in an optimal permutation, it only matters order of elements having same value in A[]. We can put firstly all elements having value 0 in A[], then all elements having value 1 in A[]. We can order elements having value 0 by case 1/ and elements having value 1 by case 4/. More exactly, suppose i1 < i2 < ... < im and (A[i1] = A[i2] = ... = A[im] = 0) and j1 > j2 > ... > jn (A[j1] = A[j2] = ... = A[jn] = 1). Then, a permutation following all rules is {i1, i2, ..., im, j1, j2, ..., jn}. This permutation can always be built.</p><p>Hence, task reduces to (*): count number of indices i, j such as i < j and A[i] = 1 and A[j] = 0. We can achieve easily an O(N) algorithm to do this. Let’s build an array cnt[j] = number of 0s in range {j, j + 1, ..., N} from array A. We can easily implement it by going backwards from N to 1. The result is sum of cnt[i], when A[i] = 1.</p><p>Code: <a href=\"http://pastie.org/8651813\">http://pastie.org/8651813</a></p><h1><a href=\"/contest/384/problem/D\" title=\"Codeforces Round 225 (Div. 2)\">384D - Volcanoes</a></h1><p>Our first observation is that if there is a path from (1, 1) to (N, N), then the length of path is 2 * N – 2. Since all paths have length 2 * N – 2, it follows that if there is at least one path, the answer is 2 * N – 2 and if there isn’t, the answer is -1. How to prove it? Every path from (1, 1) to (N, N) has exactly N – 1 down directions and exactly N – 1 right directions. So, total length for each path is N – 1 + N – 1 = 2 * N – 2. </p><p>So we reduced our problem to determine if there is at least one path from (1, 1) to (N, N). This is the challenging part of this task, considering that N <= 10 ^ 9. How would you do it for a decently small N, let’s say N <= 10^3 . One possible approach would be, for each row, keep a set of reachable columns. We could easily solve this one by doing this: if (i, j) denotes element from ith row and jth column, then (i, j) is (is not) reachable if:</p><p>if (i, j) contains a volcano, then (i, j) is not reachable. Otherwise, if at least one of (i – 1, j) and (i, j – 1) is reachable, then (i, j) is reachable. Otherwise, (i, j) is not reachable.</p><p>What’s the main problem of this approach? It needs to keep track of 10^9 lines and in worst case, each of those lines can have 10^9 reachable elements. So, worst case we need 10^9 * 10^9 = 10^18 operations and memory.</p><p>Can we optimize it? We can note for beginning that we don’t need to keep track of 10^9 lines, only m lines are really necessarily. We need only lines containing at least one obstacle (in worst case when each line contains only one obstacle, we need m lines). How to solve it this way? Suppose line number x contains some obstacles and lines x + 1, x + 2, x + 3 do not contain any obstacle. Suppose we calculated set S = {y | cell (x, y) is reachable}. How would look S1, S2, S3 corresponding to lines x + 1, x + 2, x + 3? For S1, we can reach cell (x + 1, ymin), where ymin is minimal value from set S. Then, we can also reach {ymin + 1, ymin + 2, ..., N}, by moving right from (x + 1, ymin). So S1 = {ymin, ymin + 1, ..., N}. How do S2 and S3 look? It’s easy to see that they’ll be as well {ymin, ymin + 1, ..., N}. So we get following optimization: suppose set of lines containing at least one obstacle is {L1, L2, ..., Lk}. We need to run algorithm only for lines L1, L1 + 1, L2, L2 + 1, L3, L3 + 1, ..., Lk, Lk + 1.</p><p>It looks like we didn’t make anything with this optimization. Even if we calculate for m lines, each line can still have 10^9 reachable positions. So worst case we perform 10^14 operations. We need something better for managing information from a line. You can note that for a given line y, there are a lot of positions having consecutive values. There are a lot of positions (x, y) and (x, y + 1) both reachable. This should give us following idea: what if instead of keeping reachable positions, we keep reachable ranges? That is, for each line x we keep a set of ranges S = {(a, b) | all cells (x, k) with a <= k <= b are reachable}. </p><p>How many ranges can it be for a line? If the line contains m obstacles, there are m + 1 ranges. Suppose for line x all cells are reachable, but for line x + 1 cells (x + 1, 3) (x + 1, 5) (x + 1, N – 1) are blocked. Then, the ranges of reachable cells are [1, 2] [4, 4], [6, N – 2] and [N, N]. By now, we get worst case m lines and worst case each line having m elements, so in worst case we’d have to handle m * m = 10 ^ 10 events. This may still look too much, but happily this bound is over estimated. If a line has o obstacles, there can be at most o + 1 ranges. If lines L1, L2, ..., Lk have {o1, o2, ..., ok} obstacles, there’ll be at most o1 + o2 + ... + ok + k ranges. But o1 + o2 + ... + ok = m and also k is at most m (proved above why we’re interested in at most m lines), so in worst case we get m + m = 2 * m ranges. Yaay, finally a decent number of states for this problem :)</p><p>So, we iterate each line we’re interested in. Let’s find set of ranges for this line, thinking that all cells from line above are reachable. This is easy to do. After we get our ranges like all cells from above can be visited, let’s think how having obstacles above can influence current ranges. After adding ranges from above, current ranges can’t increase (obviously), they can only decrease, remain the same or some of them can become empty. So, let’s take each range [a, b] from current line and see how it will transform after adding ranges from previous line. </p><p>Given range [a, b], it can transform only in [a’ , b] with a’ >= a. If a’ > b, then obviously range is empty. Why second number of range keeps constant? Let a’ smallest reachable column from current line which is in range [a, b]. It’s enough to check a’ >= a, as if a’ > b, range will be empty. It’s obviously why we need to keep a’ smallest value possible >= a: we’re interested to keep range as big as possible and as less as we cut from left, as big it is. Once we’ve found a’ in range [a, b] (or a’ > b if range is empty) all cells {a’ + 1, a’ + 2, ..., b} are reachable as well by going right from a’, so if interval is not empty, then second number defining it remains b.</p><p>Next question is how to find a’ fast enough. In order a point a’ to be reachable on current range, it also needs to exist a range on previous line containing it. If the range from previous line is [pa, pb] then a’ needs to follow 3 conditions:</p><p>a’ minimal such as</p><p>pa <= a’ <= pb</p><p>a’ >= a</p><p>What if instead of finding a’ we find [pa, pb]? Then a’ is max(pa, a). In order a’ to be as small as possible, since a is constant, pa needs to be as small as possible. So we reduced it to:</p><p>pa minimal pb >= a’ >= a <=> pb >= a</p><p>Intervals from previous line are disjoint, no 2 intervals cross each other. It means that if pb is minimal, than pa is minimal too (if we increase pb, then pa will increase too, so it won’t be minimal). Hence, you need to find an interval [pa, pb] such as pb is minimal and pb >= a. Then, a’ is max(a, pa). This is easy to do if we sort all intervals from previous line increasing by second value (pb), then we binary search for value a. </p><p>Finally, after running algorithm for all lines, last range from last line has second number N (assuming ranges are sorted increasing by second value), then there exist a path, otherwise there does not exist. This algorithm should run O(m * logm) worst case, good enough to pass. </p><p>Code: <a href=\"http://pastie.org/8651817\">http://pastie.org/8651817</a></p><h1><a href=\"/contest/384/problem/E\" title=\"Codeforces Round 225 (Div. 2)\">384E - Propagating tree</a></h1><p>This is kind of task that needs to be break into smaller subproblems that you can solve independently, then put them together and get solution.</p><p>Let’s define level of a node the number of edges in the path from root to the node. Root (node 1) is at level 0, sons of root are at level 1, sons of sons of root are at level 2 and so on.</p><p>Now suppose you want to do an operation of type 1 to a node x. What nodes from subtree of x will be added +val (a positive value)? Obviously, x will be first, being located at level L. Sons of x, located at level L + 1 will be added –val. Sons of sons, located at level L + 2, will be added value +val again. So, nodes from subtree of x located at levels L, L + 2, L + 4, ... will be added a +val, and nodes located at levels L + 1, L + 3, L + 5 will be added a –val. Let’s take those values of L modulo 2. All nodes having remainder L modulo 2 will be added a +val, and nodes having reminder (L + 1) modulo 2 will be added –val. In other words, for a fixed x, at a level L, let y a node from subtree of x, at level L2. If L and L2 have same parity, +val will be added to y. Otherwise, -val will be added to y.</p><p>From here we have the idea to split nodes of tree in 2 sets – those being located at even level and those being located at odd level. What still makes the problem hard to solve? The fact that we have a tree. If nodes from a subtree would be a contiguous sequence instead of some nodes from a tree, problem would be simpler: the problem would reduce to add / subtract values to all elements of a subarray and query about a current value of an element of array. So, how can we transform tree to an array, such as for a node x, all nodes from subtree of x to be a subarray of array?</p><p>The answer is yes. We can do this by properties of DFS search. Before reading on, make sure that you know what is discovery time and finish time in a DFS search. Let’s build 3 arrays now – discover[], representing nodes in order of their discover times (a node is as before in discover as it has a small discover time), begin[] = for a node, in which time it was discovered and end[] = what’s last time of a discovered node before this node finishes. For a subtree of x, all nodes in the subtree are nodes in discover from position begin[x] to end[x].</p><p>Example: suppose you have tree 1-5; 1-6; 6-7; 6-4; 4-2; 4-3</p><p>Discover is {1, 5, 6, 7, 4, 2, 3}.</p><p>begin is {1, 6, 7, 5, 2, 3, 4}.</p><p>end is {7, 6, 7, 7, 2, 7, 4}.</p><p>What’s subtree of node 6? elements of discover from position begin[6] to end[6]. In this case, from 3 to 7, so elements {6, 7, 4, 2, 3}. You can see it’s correct and take more examples if you want :)</p><p>Now, we reduced problem to: you’re given an array A. you can perform 2 operations:</p><p>1/ increase all elements from a range [x, y] to a value val (val can be negative, to treat subtractions)</p><p>2/ what’s current value of an element from position pos.</p><p>Those who solved “Iahub and Xors” from my last round, CF 198, should probably say they saw something similar before. If you didn’t solve problem before, I encourage you to do it after you solve this one, it uses a similar idea to what will follow now. Also, if you don’t know Fenwick trees, please read them before moving on. An alternative would be for this task using segment trees with lazy update, but I see this one more complicated than needed.</p><p>I’ll use now a not so common approach when dealing with data structures. Instead of keeping in a node the result, like you usually do, I’ll keep just an auxiliary information. So what algorithm proposed does:</p><p>Let A an array, initially with all elements 0.</p><p>When you need to update range [x, y] with value val, you simply do A[x] += val and A[y + 1] -= val.</p><p>When you need to answer a query about position pos, you output A[1] + A[2] + ... + A[pos].</p><p>Implemented brute force, you get O(1) per update and O(N) per query. However, these both are operations supported by a Fenwick tree, so you can get O(logN) per operation.</p><p>It may not be very clear why this algorithm works. Let’s take a closer look: an update needs to add value val only to range [x, y]. When you query a position pos, let’s see if algorithm handles it correctly:</p><p>1/ pos < x. In this case, result must not be affected by my update. Since pos < x and I only updated 2 values with indices >= x, when doing A[1] + A[2] + ... + A[pos] it won’t matter at all I did that update – at least not for this query.</p><p>2/ x <= pos <= y. Here, for a pos, I need to add value val only once. We add it only at A[x] – in this way it will be counted once, and it will be considered for each elements from range [x, y] (since an element at position p from range [x, y] has p >= x, in A[1] + A[2] + ... + A[p] I’ll have to consider A[x]).</p><p>3/ pos > y. Here I don’t have to consider the query. But it would be considered when processing A[x]. But if I add to A[y + 1] value –val I’ll just cancel the value previously added.</p><p>Code (actually we use just one Fenwick tree instead of 2, can you think why it works? :) ) : <a href=\"http://pastie.org/8651824\">http://pastie.org/8651824</a></p><h1><a href=\"/contest/383/problem/D\" title=\"Codeforces Round 225 (Div. 1)\">383D - Antimatter</a></h1><h2>Author's solution</h2><p>The problem is: given an array, iterate all possible subarrays (all possible elements such as their indexes are consecutive). Now, for a fixed subarray we need to know in how many ways we can color its elements in black and white, such as sum of black elements is equal to sum of white elements. The result is sum of this number, for each subarray.</p><p>Let’s solve an easier problem first. This won’t immediately solve the harder version, but it will be useful later. Suppose you’ve fixed a subarray. In how many ways can you color it with black and white? Suppose subarray has N elements and sum of them is M. Also, suppose for a coloring, sum of blacks is sB and sum of whites is sW. For coloring to be valid, sB = sW. But we also know that sB + sW = M (because each element is colored by exactly one color). We get that 2 * sB = M, so sB = M / 2. The problem is now: in how many ways can we color elements in black such as sum of blacks is M / 2 (after we fix a black coloring, we color with white non colored elements; sum of white colored elements is also M / 2). This is a well known problem: Knapsack problem. Let ways[i][j] = in how many ways one can obtain sum j from first i elements. When adding (i + 1) object, after ways[i] is calculated, for a fixed sum j we can do 2 things: add (i + 1) object to sum j or skip it. Depending of what we chosen, we add value ways[i][j] to ways[i + 1][j + value[i + 1]] or to ways[i + 1][j]. The result is in ways[N][M / 2]. This works in O(N * M) time.</p><p>An immediate solution can be obtained now: take all subarrays and apply above approach. This leads to an O(N ^ 2 * M ^ 2) solution, which is too much. One can reduce complexity to O(N ^ 2* M) by noting that processing subarray [i, j] can be done with already calculated values for subarray [i, j – 1]. Hence, instead of adding N elements, it’s enough to add 1 element to already calculated values (element from position j). Sadly, O(N ^ 2 * M) is still too slow, so we need to find something better. The solution presented below will look forced if you didn’t solve some problems with this technique before. It’s hard to come with an approach without practicing this kind of tasks. But don’t worry, as much as you practice them, as easily you’ll solve those problems.</p><p>We’ll solve task by divide and conquer. Complexity of this solution is O(N * M * logN). Let f(left, right) a function that counts number of colorings for each subarray [i, j], such as subarray [i, j] is included in subarray [left, right] (left <= i <= j <= right). Answer is in f(1, N). The trick is to define a value med = (left + right) / 2 (very frequent trick in divide and conquer problems, called usually a median). We can next classify [i, j] subarrays in 3 types:</p><p>1/ i <= med j <= med</p><p>2/ i > med j > med</p><p>3/ i <= med j > med</p><p>We can solve 1/ and 2/ by calling f(left, med) and f(med + 1, right). The remained problem is when i <= med and j > med. If we solve 3/ in O((right – left) * M) time, this will be enough to overall achieve O(N * M * logN) (for this moment trust me, you’ll see later why it’s so :) ).</p><p>Let’s denote by i1 last i1 elements from subarray [left, med]. Also, let’s note by i2 first i2 elements from subarray [med + 1, right]. For example, let left = 1 and right = 5, with array {1, 2, 3, 4, 5}. med is 3 and for i1 = 2 and i2 = 1, “left” subarray is {2, 3} and “right” subarray is {4}. By iterating i1 from 1 to med – left + 1 and i2 from 1 to right – med and then unite subarrays i1 and i2, we obtain all subarrays described in 3/ . Let’s denote by j1 sum of a possible black coloring of i1. Similarly, j2 is sum of a possible black coloring of i2.</p><p>Suppose we fixed i1, i2, j1 and j2. When it’s the coloring valid? Let S sum of united subarrays i1 and i2 (S = value[med – i1 + 1] + value[med – i1 + 2] + ... + value[med] + value[med + 1] + ... + value[med + i2 – 1] + value[med + i2]). Now it’s time to use what I explained at the beginning of solution. The coloring is good only when j1 + j2 = S / 2. We can rewrite the relation as 2 * (j1 + j2) = sum_of_elements_from_i1 + sum_of_elements_from_i2. We can rewrite it even more:</p><p>2 * j1 + 2 * j2 — sum_of_elements_from_i1 — sum_of_elements_from_i2 = 0</p><p>2 * j1 – sum_of_elements_from_i1 = sum_of_elements_from_i2 – 2 * j2 = combination_value</p><p>This relation is the key of solving problem. You can see now that relation is independent in “left” and “right” side. We calculate left[i1][j1] and right[i2][j2] = in how many ways can I obtain sum of blacks j1 (j2) from first i1 (i2) from left (right) side. Let’s calculate also count[value] = in how many ways can I obtain combination_value equal to value in the right side. For some fixed (i2, j2) I add to count[sum_of_elements_from_i2 – 2 * j2] value right[i2][j2]. In this way count[] is calculated correctly and completely. Now, let’s fix a sum (i1, j1) in the left side. We’re interested how many good colorings are such as there exist a coloring of j1 in i1 elements (the endpoint of “left” is fixed to be i1 and I need to calculate endpoints i2 for right, then to make colorings of i2). A coloring is good if combination_value of (i1, j1) and (i2, j2) is equal. Hence, I need to know in how many ways I can color i1 elements to obtain sum j1 and also I need to know in how many ways I can color elements from right to obtain same combination_value as it’s in the left. It’s not hard to see that answer for a fixed (i1, j1) is left[i1][j1] * count[2 * j1 – sum_of_elements_from_i1]. This takes O((right – left) * M) time.</p><p>The only thing remained in the problem is to see why complexity is O(N * M * logN). We can assume N is a power of 2 (it not, let’s round N to smallest power of 2 bigger than N; complexity for N is at least as good as complexity for this number). Draw a binary complete tree with N nodes. Each node corresponds to an appeal of f(). For a level, exactly O(N * M) operations are performed. To see why:</p><p>For level 1, there’ll be 1 node performing N * M operations.</p><p>For level 2, there’ll be 2 nodes performing (N / 2) * M operations. Summing up we get O(N * M).</p><p>For level 3, there’ll be 4 nodes performing (N / 4) * M operations. Summing up we get O(N *M) as well.</p><p>and so on.</p><p>So for each level we perform O(N * M) operations. A binary complete tree has maximum O(logN) levels, so overall complexity is O(N * M * logN).</p><p>Code: <a href=\"http://pastie.org/8651826\">http://pastie.org/8651826</a></p><h2>Solution fount by contestants</h2><p>This was totally unexpected to us :) Good job finding it, you guys are really smart. </p><p>We observe that x units of antimatter is the same thing as -x units of matter. Then we can consider that an element produces either x or -x units of matter. A valid substring is one that can have the sum of the elements 0. The problem is reduced to finding how many different substrings can we have with sum 0 (a substring is different than another one if it has different indices, or if at least one element produces matter in one and antimatter in the other).</p><p>This problem can be solved with dynamic programming. We will hold D[i][j] = the number of substrings that end in element i, and have sum j. It's easy to see that D[i + 1][j] = D[i][j — x] + D[i][j + x], where x is the value of the current element (we can put either -x or x). After we finish computing all the values for current i, we add to the solution D[i][0] (how many valid substrings do we have). After that, we add 1 to D[i][0], meaning that there is an empty substring starting at position i (however, we don't need to add it to the answer).</p><p>For a code, check passing submissions during contest. </p><h2><a href=\"/contest/383/problem/E\" title=\"Codeforces Round 225 (Div. 1)\">383E - Vowels</a></h2><h2>Author's solution</h2><p>Let's iterate over all possible vowel sets. For a given set {x1, x2, ..., xk} we're interested in number of correct words from dictionary. After a precalculation, we can do it in O(k).</p><p>Suppose our current vowel set is {x1, x2, ..., xk}. How many words are covered by the current vowels? By definition, we say a word is covered by a set of vowels if at least one of 3 letters of word is in vowel set. We can calculate this number using principle of inclusion and exclusion. We’ll denote by |v1, v2, v3, ...| = number of words containing ALL of vowels v1, v2, v3, ... . Using principle of inclusion and exclusion we get:</p><p>number_of_words_covered = |x1| + |x2| + .. + |xk| — |x1, x2| — |x1, x3| — .... + |x1, x2, x3| + |x1, x2, x4| + .... + |xk-2, xk-1, xk|. This formula is simply a reformulation of principle of inclusion and exclusion. You can easily observe that |v1, v2, ..., vk| makes sense only when k is at most 3, as no word from input can contain 4 or more letters (and hence can’t contain 4 or more vowels). </p><p>Example:</p><p>Suppose words are abc, abd and bcd. </p><p>|a| = 2 (first 2 words both contain character a).</p><p>|a, b| = 2 (as well, first 2 words contain characters a and b).</p><p>|b| = 3 (all 3 words contain character b).</p><p>|a, b, d| = 1 (only second word contains all 3 characters).</p><p>Also, note how principle of inclusion and exclusion works. number of words covered for vowels {a, b} is |a| + |b| — |a, b| = 2 + 3 – 2. Indeed, answer is 3.</p><p>We divide our problem in 3 subproblems. First one, for a vowel set, compute sum of |a|, where a is a letter from subset. Second, compute sum of |a, b|, where both a and b are letters from set. Third, compute sum of |a, b, c|, where a, b, c are letters from set. As stated, the answer is number_from_1st_step + number_from_3rd_step – number_from_2nd_step. If you followed me, you’ll see that we want to compute results for each subproblem in O(queryLetters).</p><p>First subproblem can be solved trivially in O(queryLetters). Let array single[], with following meaning: single[c] is how many words contain character c. It can be trivially precomputed in O(24 * N). Note that if a word contains twice/third times a character c, it needs to be counted only one (e.g. word aba will add only 1 to single[a]). For compute result of this subproblem for a given set of vowels, I’ll take all letters from set. If letter belongs to set, I add to result single[letter]. This step can be also be solved in O(1), but there’s no need, since other subproblems allow only an O(queryLetters) solution. </p><p>For second and third subproblems it’s a little more difficult. I’ll present here how to solve second subproblem and some hints for third one (if you understand second, with hints you should be able to solve third one by your own).</p><p>Similarly to first step, I’ll define a matrix double[c1][c2] = how many words contain both characters c1 and c2. A trivially solution would be, for a given vowel set, take all combinations of letters c1 and c2 that belong to set and add to result value double[c1][c2]. However, this solves each query in O(queryLetters^2), which is too slow.</p><p>Note, if we’d have 12 letters, instead of 24, this approach would be fast enough. From here it comes a pretty classical idea in exponential optimization: meet in the middle attack. We split those 24 letters in 2 groups: first 12 letters and last 12 letters. The answer for a subset is sum of double[c1][c2] (when c1 and c2 belong to current vowel set) when</p><p>1/ c1 and c2 belong to first 12 letters</p><p>2/ c1 and c2 belong to last 12 letters</p><p>3/ c1 belongs to first 12 letters and c2 belongs to last 12 letters</p><p>1/ and 2/ can be immediately precalculated as stated above, in O(2 ^ 12 * 12 ^ 2). We’ll remember results for each half using bitmasks arrays. Let Half1[mask] = sum over double[c1][c2], when c1 and c2 are in first 12 letters and correspond to 1 bits of mask. Half2[mask] is defined similarly, but for last 12 letters (e.g. subset {a, c, d} corresponds to bitmask 2^0 + 2^2 + 2^3 = 13 in first half and subset {m, n, p} corresponds to bitmask 2^0 + 2^1 + 2^3 = 11 for second half). Now, for a given subset, one can answer first 2 parts in O(queryCount) worst case (read input for a query and convert it to bitmasks). </p><p>How to answer 3? With another precalculation, of course. We know c1 letter needs to be in first 12 letters and c2 needs to be in last 12 letters. The precalculation we do here is: mixed_half[mask][i] = sum over |c1, c2|, when c1 belongs to first half and is a 1 bit of mask and c2 is i-th character of second half. Hence, for a query, we can fix character from second half (c2, by iteration of query letters from second half) and know sums of |c1, c2| between it and all available characters from first half after we do this precalculation. Also, precalculation is done trivially in O(2 ^ 12 * 12^2): fix mask, fix i and then iterate over 1 bits from mask and add double[c1][c2]. </p><p>Third subproblem is left, but it can be done similarly to second one. Instead of double[c1][c2], we’ll have triple[c1][c2][c3] = how many words contain all 3 characters c1, c2 and c3? We also do meet in the middle here, divide those 24 letters into 2 sets of 12 letters. We have 4 cases:</p><p>1/ c1, c2, c3 belong to first half</p><p>2/ c1, c2, c3 belong to second half</p><p>3/ c1, c2 belong to first half and c3 to second half</p><p>4/ c1 belongs to first half and c2, c3 to second half</p><p>1/ and 2/ are done brute force, like in second subproblem (the only difference is we choose 3 characters instead of 2, having complexity O(2 ^ 12 * 12 ^ 3)). For 3/ and 4/ we also precompute 2 matrixes: </p><p>mixed_two_one[mask][i] = c1 and c2 belong to mask from first half and c3 is i-th character from second half </p><p>and </p><p>mixed_one_two[mask][i] = c1 is i-th character from first half and c2, c3 belong to mask from second half. </p><p>Those can also be calculated in O(2 ^ 12 * 12^3).</p><p>So precalculation part is O(2 ^ 12 * 12 ^ 3) = 7077888 operations.</p><p>For calculate answering queries complexity, take all numbers from 0 to 2^24 — 1 and sum their bit count. This is a well known problem, the sum is 0 * C(24, 0) + 1 * C(24, 1) + ... + 24 * C(24, 24) = 201326592. In total we get 208404480 operations. C++ source makes them in 2 seconds. </p><p>Code: <a href=\"http://pastie.org/8651829\">http://pastie.org/8651829</a></p><h2>Solution fount by contestants</h2><p>Like in D1 D task, official solution was over complicated. This solution is more simple to understand, code and it's more elegant. If someone wants to complicate his life, (s)he can code also official solution :)</p><p>Let's start by assigning a bitmask to each word in following way: ith bit is 1 if and only if letter ('a' + i) appears in the current word. For example, for word acd, its bitmask is 2^0 + 2^2 + 2 ^ 3 = 13 and for word aab its bitmask is 2^0 + 2^1 = 3. After reading the words from dictionary, we store a matrix cnt[mask] = how many words from dictionary correspond to mask?</p><p>We iterate bitmasks from 0 to 2^24 — 1, this time corresponding to each possible question of Iahubina. Let's focus on a bitmask X. We need to get sum of cnt[mask], when mask and X share at least one common bit having value 1 (formally (X AND mask) > 0). In order to do this, we need a reduction which may be not so obvious. </p><p>What if instead of counting all words containing at least one of vowels {w1, w2, ..., wk} we count all words which don't contain ANY of vowels {w1, w2, ..., wk}? Suppose this number is ret. Then, all words containing at least one of vowels is N — ret. From all words, we erase those words which do not contain any vowels from set {w1, w2, ..., wk} (and which obviously are wrong words). Obviously, it's left only words containing at least one vowel, so good words. Now, for a word not to contain any of vowels {w1, w2, ..., wk} it needs to contains ONLY vowels from set {"a", "b", "c", ..., "x"} \\ {w1, w2, ..., wk} (set of allowed letters from which we erased vowels w1, w2, ..., wk}. </p><p>And this is reduction we needed. For a bitmask X we need to calculate sum of cnt[mask], where mask is a subset of X (we can set some bits from X from 1 to 0 in order to obtain mask). For a mask, let's keep this sum in res[mask]. We can calculate res array using divide and conquer.</p><p>Let's make a function solve(left, right), which completes array res in the way described above, if we consider only elements cnt[k] with left <= k < right (for simplicity, I'll consider elements which do not lie in this range to be equal to 0). Now we need to solve for a range [left, right]. Let's have in res1[] = solve(left, med) and in res2[] = solve(med, right), where med = (left + right) / 2. We need to put together res1[] and res2[] in order to obtain res[].</p><p>for (int i = left; i < med; ++i) res[i] = res1[i];</p><p>Numbers in [left, med] have most significant bit equal to 0. We can only keep it 0 and add what we calculated before. We can't add any element from res2[], because those elements have most significant bit equal to 1 and we're not allowed to change bit 0 into bit 1.</p><p>for (int i = med; i < right; ++i) res[i] = res1[i — med] + res2[i];</p><p>Here, most significant bit is 1. Adding res1[] corresponds to changing bit from 1 to 0, adding res2[] corresponds to leaving bit 1.</p><p>Of course, we need to threat the base case here, too. When left + 1 = right, res[left] = cnt[left]. We can keep only one array res[] instead of 3, I explained it this way only for simplicity. Also, there is no need for keeping separate arrays for res[] and cnt[], one can solve all task with only one array. In order to get res[], we simply call solve(0, 2^24).</p><p>Complexity of solution is O(2 ^ 24 * 24). I leave the proof homework, it's almost identical to complexity proof of D1 D "Author solution" (that with building a binary tree).</p><p>For a reference solution, check <a class=\"rated-user user-red\" href=\"/profile/Endagorion\" title=\"Grandmaster Endagorion\">Endagorion</a>'s AC source during contest. </p></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/384\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 225 (Div. 2)</a> </span>\r\n </div>\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/383\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 225 (Div. 1)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-12457-10531\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"12457\",\n blogEntryId: \"10476\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n <div style=\"font-size: 1.1rem;line-height: 11px;\">\r\n <img style=\"vertical-align: middle;\" src=\"//codeforces.org/s/81027/images/blog/tags.png\" title=\"Tags\" alt=\"Tags\"/>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=codeforces\" class=\"tag notice\" style=\"text-decoration: none;\">codeforces</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=225\" class=\"tag notice\" style=\"text-decoration: none;\">225</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=editorial\" class=\"tag notice\" style=\"text-decoration: none;\">editorial</a>\r\n </span>\r\n </div>\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-10531\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+418</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-10531\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/fchirica\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/fchirica\">\n fchirica\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Jan/20/2014 22:18\">10 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/10476#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/10476#comments\">\n 52\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"10547\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (45)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158582\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PAP\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/78534/avatar/d5bcc04085999f83.jpg'/> </a>\n <div><a href=\"/profile/PAP\" title=\"Candidate Master PAP\" class=\"rated-user user-violet\">PAP</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 22:40\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158582\" href=\"?#comment-158582\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158582\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"32\"\r\n data-commentUserId=\"78534\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+32</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158582\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>perfect editorial! thanks a lot!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158582 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158582 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158582\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158591\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/eduardische\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2320/avatar/3ac70493aa90ad2e.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/eduardische\" title=\"International Master eduardische\" class=\"rated-user user-orange\">eduardische</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 22:48\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158591\" href=\"?#comment-158591\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"158591\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"158591\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"10\"\r\n data-commentUserId=\"2320\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+10</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158591\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Just would like to report a typo in 383D contestants' solution: the formula computes D[i+1][j] and not D[i][j]. Thanks for the quick editorial!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158591 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158591 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158591\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158596\" commentParentId=\"158591\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/fchirica\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/57267/avatar/4e655c69b8ad66c2.jpg'/> </a>\n <div><a href=\"/profile/fchirica\" title=\"Candidate Master fchirica\" class=\"rated-user user-violet\">fchirica</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 22:52\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158596\" href=\"?#comment-158596\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-158591\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158596\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"15\"\r\n data-commentUserId=\"57267\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+15</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158596\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks. Fixed. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158596 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158596 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158596\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158598\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Mikester\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/109566/avatar/401b6d72d8f2e768.jpg'/> </a>\n <div><a href=\"/profile/Mikester\" title=\"Master Mikester\" class=\"rated-user user-orange\">Mikester</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 22:54\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158598\" href=\"?#comment-158598\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158598\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"13\"\r\n data-commentUserId=\"109566\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+13</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158598\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>elfus has some of the best rounds on Codeforces, and definitely the best editorials. Congratulations to you and Rares for the round !</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158598 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158598 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158598\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158599\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/iPs\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/144469/avatar/10358ae72910ceac.jpg'/> </a>\n <div><a href=\"/profile/iPs\" title=\"Expert iPs\" class=\"rated-user user-blue\">iPs</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 22:54\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158599\" href=\"?#comment-158599\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158599\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"33\"\r\n data-commentUserId=\"144469\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+33</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158599\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>best editorial I have ever seen in codeforces</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158599 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158599 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158599\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158600\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/bli0042\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/88584/avatar/51c3a9b55a3537fa.jpg'/> </a>\n <div><a href=\"/profile/bli0042\" title=\"Candidate Master bli0042\" class=\"rated-user user-violet\">bli0042</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 22:54\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158600\" href=\"?#comment-158600\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"158600\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"158600\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"88584\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158600\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For Div 2C, if A[i] = A[j] = 0 and we put i before j, won't j lose milk? Or am I misinterpreting the solution?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158600 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158600 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158600\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158601\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/aabs08\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/aabs08\" title=\"Expert aabs08\" class=\"rated-user user-blue\">aabs08</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 22:55\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158601\" href=\"?#comment-158601\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"158601\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"158601\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"9\"\r\n data-commentUserId=\"86699\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+9</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158601\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>One of the best editorials i came across in codeforces :D otherwise the editorial here are really very short and objective.</p><p>Every one here should write editorials like you :) !!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158601 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158601 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158601\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158607\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Xellos\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/69675/avatar/8526bcfc8e687b43.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/Xellos\" title=\"International Grandmaster Xellos\" class=\"rated-user user-red\">Xellos</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 23:03\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158607\" href=\"?#comment-158607\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"158607\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"158607\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"17\"\r\n data-commentUserId=\"69675\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+17</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158607\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Finally a tutorial worth upvoting!</p><p>I didn't really need to think about D. As soon as I saw the constraint on <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/986936bec272878d92f9c6fb0f0ce3c5b118cc0e.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />, I decided to try a DP on (position,sum) — it was a massive hint for me. Well, sometimes it just happens that there's a simple solution, which the author doesn't realize :D. Maybe this could be eliminated by some extensive "problem testing" by random capable people?</p><p>I guess I was also lucky in not trying to solve B. I solved in the order: A (because it's easy), C (because I like it), D (because it's easy) :D</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158607 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158607 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158607\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158610\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Mostafa_36a2\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/137637/avatar/28a01293a2b409.jpg'/> </a>\n <div><a href=\"/profile/Mostafa_36a2\" title=\"Specialist Mostafa_36a2\" class=\"rated-user user-cyan\">Mostafa_36a2</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 23:09\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158610\" href=\"?#comment-158610\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158610\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"-9\"\r\n data-commentUserId=\"137637\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-9</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158610\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I've found a very short solution for Div2 C , by zxz5759209</p> <pre><code>scanf("%d",&n);\n LL cnt=0,sum=0;\n for(int i=1;i<=n;i++)\n {\n scanf("%d",&x);\n cnt+=(LL)x;\n if(!x)sum+=cnt;\n }\n printf("%I64d\\n",sum);\n</code></pre></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158610 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158610 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158610\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158641\" commentParentId=\"158610\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Robert.One\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Robert.One\" title=\"Pupil Robert.One\" class=\"rated-user user-green\">Robert.One</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 01:27\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158641\" href=\"?#comment-158641\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-158610\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158641\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"150202\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158641\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I also had this solution and i got accepted but it took 1 hour to find it during the contest</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158641 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158641 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158641\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158612\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Darek_\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Darek_\" title=\"Specialist Darek_\" class=\"rated-user user-cyan\">Darek_</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 23:12\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158612\" href=\"?#comment-158612\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158612\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"152123\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158612\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks for an informative editorial.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158612 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158612 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158612\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158618\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Mostafa_36a2\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/137637/avatar/28a01293a2b409.jpg'/> </a>\n <div><a href=\"/profile/Mostafa_36a2\" title=\"Specialist Mostafa_36a2\" class=\"rated-user user-cyan\">Mostafa_36a2</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 23:25\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158618\" href=\"?#comment-158618\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"158618\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"158618\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"137637\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158618\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Unbelivable solution for Div2,B by Sick_Coder</p> <pre><code>cin >> n >> m >> k;\n cout << m * (m - 1) / 2 << "\\n";\n\n for (1, m, i)\n \tfor (i + 1, m, j)\n \t\tif (!k)\n \t\t\tcout << i << " " << j << "\\n";\n \t\telse\t\n \t\t\tcout << j << " " << i << "\\n";\n</code></pre></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158618 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158618 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158618\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158631\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mugurelionut\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/63702/avatar/45e4d5390c215090.jpg'/> </a>\n <div><a href=\"/profile/mugurelionut\" title=\"International Master mugurelionut\" class=\"rated-user user-orange\">mugurelionut</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 23:57\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158631\" href=\"?#comment-158631\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158631\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"63702\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158631\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>A very good editorial, indeed! (but please don't forget about Div1E) And the problems were really nice. But I think problem B was tougher than it should have been for its amount of points. I've read some comments saying that problem B had too weak pretests (because so many solutions failed the final system tests). I would have to say that my experience with problem B was the exact opposite. I coded two wrong solutions (which failed some pretest or another) before eventually finding and implementing the right solution. So I'd say that problem B had good pretests :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158631 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158631 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158631\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158635\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/MohammadFatafta\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/148405/avatar/4276577919b9713d.jpg'/> </a>\n <div><a href=\"/profile/MohammadFatafta\" title=\"Specialist MohammadFatafta\" class=\"rated-user user-cyan\">MohammadFatafta</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 00:11\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158635\" href=\"?#comment-158635\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158635\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"148405\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158635\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>now this is a real editorial!! thanks guys :D</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158635 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158635 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158635\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158636\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/matrix\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/matrix\" title=\"Master matrix\" class=\"rated-user user-orange\">matrix</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 00:15\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158636\" href=\"?#comment-158636\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"158636\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"158636\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"16572\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158636\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Hi,</p><p>Great and fast editorial with complete details. </p><p>Thanks very much.</p><p>Edit: I think there is a small typo: "It’s not hard to see that answer for a fixed (i1, j1) is left[i1][j1] * value[2 * j1 – sum_of_elements_from_i1]." I guess you meant count[2 * j1 – sum_of_elements_from_i1].</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158636 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158636 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158636\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158637\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Kyuubi\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/83590/avatar/b87432a652bb276.jpg'/> </a>\n <div><a href=\"/profile/Kyuubi\" title=\"Expert Kyuubi\" class=\"rated-user user-blue\">Kyuubi</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 00:18\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158637\" href=\"?#comment-158637\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158637\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"2\"\r\n data-commentUserId=\"83590\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+2</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158637\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Best Editorials I have seen on codeforces yet! :D</p><p>For Propagating tree, how do we keep track of alternating levels in the arrays we created using DFS ? </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158637 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158637 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158637\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158640\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/k_____k\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/60285/avatar/422359e1ae9d666c.jpg'/> </a>\n <div><a href=\"/profile/k_____k\" title=\"Expert k_____k\" class=\"rated-user user-blue\">k_____k</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 01:07\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158640\" href=\"?#comment-158640\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158640\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"2\"\r\n data-commentUserId=\"60285\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+2</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158640\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Best Editorials Ever ! #thanks to the authors, for posting alternative solutions of contestants also. Great start in 2014. #Looking Forward.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158640 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158640 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158640\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158658\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/sillycross\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/41652/avatar/58966d0c793c6394.jpg'/> </a>\n <div><a href=\"/profile/sillycross\" title=\"Grandmaster sillycross\" class=\"rated-user user-red\">sillycross</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 07:49\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158658\" href=\"?#comment-158658\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158658\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"9\"\r\n data-commentUserId=\"41652\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+9</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158658\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Div1 E can be solved in O(2^24*24) or O(2^24+2^12*n)..</p><p>O(2^24*24): dp[i][s] means the sum of all contributions of subset s where all digits are same as s except the last i digits.. </p><p>O(2^24+2^12*n): the length of word is only 3. We divide the 24 letters in half, calculate the answer for all first 12 letters and all last 12 letters and merge them with brute-force. This can be solved in O(2^24). Then we subtract the words that are counted twice: these words are words that have 2 letters in first half and 1 in second half, or 2 in second half and 1 in first half. Let's consider the first case: for each subset of first 12 letters we check each word whether it has exactly 2 letters in this half, if so, we can say all masks in another half that contains the third letter need to be subtracted by 1. This can be solved in 2^12*(2^12+n). Same algorithm can be used to solve the second case. Although this algorithm runs slower than O(2^24*24) bcuz of its larger constant... </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158658 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158658 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158658\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158663\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/VeniVidiVici\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/VeniVidiVici\" title=\"Candidate Master VeniVidiVici\" class=\"rated-user user-violet\">VeniVidiVici</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 09:39\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158663\" href=\"?#comment-158663\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158663\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"149163\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158663\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Very nice editorial! Disappointed in Div 2B though, really expected the "real" problem rather than just insertion sort but that's what you get for not reading carefully ;)</p><p>However, does anyone have an accepted solution that is "real" (e.g. finds the minimum number of operations necessary and prints such a solution)? I was close but my computer died during contest and I haven't tried so much since (of course you can do O((mn)^2) easily but this is way too slow, there should be a O(n*m^2) solution but again my computer was unable to operate). My approach was to make 2-D boolean array to check if a swap is necessary, but I'm not sure if order of operations will end up being a big problem.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158663 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158663 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158663\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158685\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/LegendaryGrandmaster\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/142091/avatar/a3a5a4b5c26ac419.jpg'/> </a>\n <div><a href=\"/profile/LegendaryGrandmaster\" title=\"Specialist LegendaryGrandmaster\" class=\"rated-user user-cyan\">LegendaryGrandmaster</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 14:34\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158685\" href=\"?#comment-158685\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158685\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"142091\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158685\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>One of the best codeforces editorials ever! Thanks!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158685 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158685 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158685\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158687\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/BENYAM1N\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/84938/avatar/d2ae2657d8898e38.jpg'/> </a>\n <div><a href=\"/profile/BENYAM1N\" title=\"Master BENYAM1N\" class=\"rated-user user-orange\">BENYAM1N</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 15:24\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158687\" href=\"?#comment-158687\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"158687\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"158687\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"84938\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158687\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks a lot. very good contest and good editorial too!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158687 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158687 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158687\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158689\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/JuanMata\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/82548/avatar/a7d69af7b441c6d7.jpg'/> </a>\n <div><a href=\"/profile/JuanMata\" title=\"Expert JuanMata\" class=\"rated-user user-blue\">JuanMata</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 15:47\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158689\" href=\"?#comment-158689\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158689\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"82548\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158689\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>this is one of the best editorials on CF ever!!!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158689 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158689 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158689\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158700\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Vicfred\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/76941/avatar/d067b7433ec39337.jpg'/> </a>\n <div><a href=\"/profile/Vicfred\" title=\"Pupil Vicfred\" class=\"rated-user user-green\">Vicfred</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 16:25\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158700\" href=\"?#comment-158700\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158700\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"11\"\r\n data-commentUserId=\"76941\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+11</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158700\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>The best editorial I've read in a while here, thanks.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158700 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158700 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158700\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158727\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/beecoder\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/beecoder\" title=\"Pupil beecoder\" class=\"rated-user user-green\">beecoder</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 21:13\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158727\" href=\"?#comment-158727\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158727\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"89551\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158727\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Hi, The way I print answers for 'Coder Problem' is as follows. This takes 124 ms. is there a way to print the answers faster ? </p> <pre><code> \tfor (int i = 0 ; i < number ; i ++ ) { \n \t\tfor (int k = 0 ; k < number ; k ++ ) { \n \t\t\tif (flag) {\n \t\t\t\tif ( k % 2 == 1) out.print('.');\n \t\t\t\tif( k% 2 == 0 ) out.print('C');\n \t\t\t} else {\n \t\t\tif ( k % 2 == 1) out.print('C');\n \t\t\tif( k% 2 == 0 ) out.print('.');\t\n \t\t\t}\n \t\t}\n \t\tif (flag) flag = false;\n \t\telse flag = true;\n \t\tout.print("\\n");\n \t}\n \n</code></pre></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158727 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158727 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158727\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158742\" commentParentId=\"158727\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Mostafa_36a2\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/137637/avatar/28a01293a2b409.jpg'/> </a>\n <div><a href=\"/profile/Mostafa_36a2\" title=\"Specialist Mostafa_36a2\" class=\"rated-user user-cyan\">Mostafa_36a2</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/22/2014 14:00\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158742\" href=\"?#comment-158742\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-158727\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158742\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"137637\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158742\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>As the line contains k characters , and every odd lines are identical , also the even ones,</p><p>you can build 2 strings [C.C.C.C] and [.C.C.C.] and print them alternately </p><p>[In my opinion Java is slow language any way ]</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158742 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158742 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158742\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158752\" commentParentId=\"158727\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/t_thirupathi\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/146179/avatar/98c28348196ce4ca.jpg'/> </a>\n <div><a href=\"/profile/t_thirupathi\" title=\"Specialist t_thirupathi\" class=\"rated-user user-cyan\">t_thirupathi</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/22/2014 18:19\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158752\" href=\"?#comment-158752\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-158727\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158752\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"146179\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158752\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Modulo operations are time consuming.</p><p>To check if a number <code>n</code> is odd, you could use <code>if (n & 1)</code></p> <pre><code>for (int i = 0; i < n; i++) {\n for (int j = 0; j < n; j++)\n if ((i + j) & 1)\n out.print('.');\n else \n out.print('C');\n out.print('\\n');\n}\n</code></pre></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158752 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158752 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158752\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158745\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/JuanMata\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/82548/avatar/a7d69af7b441c6d7.jpg'/> </a>\n <div><a href=\"/profile/JuanMata\" title=\"Expert JuanMata\" class=\"rated-user user-blue\">JuanMata</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/22/2014 14:49\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158745\" href=\"?#comment-158745\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"158745\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"158745\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"82548\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158745\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>i think there is a small bug in the <a href=\"http://pastie.org/8651824\">pastie link</a> u posted for the solution of Div1 C problem.</p><p>i submitted almost exact copy of it (<a href=\"/contest/383/submission/5769615\" title=\"Submission 5769615 by JuanMata\">5769615</a>), but got WA#6. then i found the bug, corrected it and resubmitted (<a href=\"/contest/383/submission/5769890\" title=\"Submission 5769890 by JuanMata\">5769890</a>) and got AC.</p><p>referring to my two submissions, corrections in line <strong>68</strong> (last statement of <strong>dfs</strong>) and line <strong>109</strong> (the second call to <strong>update</strong>).</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158745 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158745 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158745\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"615836\" commentParentId=\"158745\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/adityakr007\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/adityakr007\" title=\"Expert adityakr007\" class=\"rated-user user-blue\">adityakr007</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/05/2020 18:54\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-615836\" href=\"?#comment-615836\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-158745\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"615836\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"866209\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-615836\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can you explain what exactly have you done in your submission (<a href=\"/contest/383/submission/5769890\" title=\"Submission 5769890 by JuanMata\">5769890</a>) for this problem?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-615836 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-615836 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-615836\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"629531\" commentParentId=\"615836\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/JuanMata\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/82548/avatar/a7d69af7b441c6d7.jpg'/> </a>\n <div><a href=\"/profile/JuanMata\" title=\"Expert JuanMata\" class=\"rated-user user-blue\">JuanMata</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/25/2020 18:14\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-629531\" href=\"?#comment-629531\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-615836\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"629531\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"82548\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-629531\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>sorry bro i've forgotten ... that was over 6yrs ago now!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-629531 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-629531 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-629531\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158751\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/TempuX\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/30820/avatar/c50adc243ea4e2fa.jpg'/> </a>\n <div><a href=\"/profile/TempuX\" title=\"Specialist TempuX\" class=\"rated-user user-cyan\">TempuX</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/22/2014 17:07\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158751\" href=\"?#comment-158751\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158751\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"30820\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158751\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Hi, I tried to implement the Volcano problem in the way explained in the editorial but I'm getting TLE. Here is my code <a href=\"//codeforces.com/contest/384/submission/5770818\">submission</a> What am I doing wrong ? Thanks anyway.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158751 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158751 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158751\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158811\" commentParentId=\"158751\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/TempuX\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/30820/avatar/c50adc243ea4e2fa.jpg'/> </a>\n <div><a href=\"/profile/TempuX\" title=\"Specialist TempuX\" class=\"rated-user user-cyan\">TempuX</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/23/2014 17:29\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158811\" href=\"?#comment-158811\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-158751\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158811\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"30820\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158811\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Turns out my binary search is causing the problem and I don't see what is wrong with it... I would appreciate any ideas.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158811 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158811 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158811\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159025\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/bboy_drain\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/76710/avatar/e0feb3aa135911d4.jpg'/> </a>\n <div><a href=\"/profile/bboy_drain\" title=\"Expert bboy_drain\" class=\"rated-user user-blue\">bboy_drain</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/25/2014 01:34\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159025\" href=\"?#comment-159025\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159025\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"76710\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159025\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Wow! This really helped me a lot! Very detailed explanations!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159025 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159025 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159025\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159092\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/AlexandruValeanu\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/131651/avatar/1c7d989c45052941.jpg'/> </a>\n <div><a href=\"/profile/AlexandruValeanu\" title=\"Candidate Master AlexandruValeanu\" class=\"rated-user user-violet\">AlexandruValeanu</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/25/2014 21:27\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159092\" href=\"?#comment-159092\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159092\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"131651\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159092\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>It was by far your best round on Codeforces, <a class=\"rated-user user-blue\" href=\"/profile/fchirica\" title=\"Expert fchirica\">fchirica</a>. The problems were great, very different one from the other and some of them didn't require any algorithmic skills at all. Good job!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159092 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159092 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159092\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159261\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lawsonh\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/lawsonh\" title=\"Expert lawsonh\" class=\"rated-user user-blue\">lawsonh</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/28/2014 06:33\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159261\" href=\"?#comment-159261\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"159261\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"159261\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"55047\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159261\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>for div1 383C should end[5] = 7? edit: nvm drew the tree wrong</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159261 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159261 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159261\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159474\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/tiagonapoli\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/150060/avatar/6615fcab66b23361.jpg'/> </a>\n <div><a href=\"/profile/tiagonapoli\" title=\"Candidate Master tiagonapoli\" class=\"rated-user user-violet\">tiagonapoli</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/30/2014 22:28\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159474\" href=\"?#comment-159474\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159474\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"150060\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159474\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Great Editorial! Thanks so much, i've learned a lot!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159474 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159474 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159474\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159707\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lchf\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/60496/avatar/e9939e755252ec16.jpg'/> </a>\n <div><a href=\"/profile/lchf\" title=\"Candidate Master lchf\" class=\"rated-user user-violet\">lchf</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/02/2014 17:28\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159707\" href=\"?#comment-159707\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159707\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"60496\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159707\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Amazing solution by Endagorion.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159707 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159707 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159707\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"177400\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/sourabh912\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/57335/avatar/bf83b9340e3cbb17.jpg'/> </a>\n <div><a href=\"/profile/sourabh912\" title=\"Specialist sourabh912\" class=\"rated-user user-cyan\">sourabh912</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/12/2014 20:39\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-177400\" href=\"?#comment-177400\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"177400\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"57335\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-177400\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In Div 1C problem, I could not understand how it can be solved using single fenwick tree from the solution link in the editorial. Can anyone please help.</p><p>Thanks</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-177400 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-177400 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-177400\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"291157\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/l_Love_KFC\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/258117/avatar/bbaec3ce1613f5bd.jpg'/> </a>\n <div><a href=\"/profile/l_Love_KFC\" title=\"Expert l_Love_KFC\" class=\"rated-user user-blue\">l_Love_KFC</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Apr/29/2016 08:23\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-291157\" href=\"?#comment-291157\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"291157\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"258117\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-291157\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In Div.1 A I didn't catch the point that in 1st, quote : "If we put i before j, no additional cost will be added. Since j is in right of i and i only adds cost when it finds elements in left of i, j won’t be affected when processing i." Won't we lose milk if we put firstly i, in case of that j sees that and loses milk? Or am I misunderstanding the task? </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-291157 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-291157 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-291157\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"309434\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/haleyk100198\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/416324/avatar/f2d97d505af17e9d.jpg'/> </a>\n <div><a href=\"/profile/haleyk100198\" title=\"Candidate Master haleyk100198\" class=\"rated-user user-violet\">haleyk100198</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/11/2016 06:32\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-309434\" href=\"?#comment-309434\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"309434\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"416324\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-309434\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I wonder how the problem Div1C can be converted to a segment tree lazy propagation implementation question, for trees like (1-2 2-3 3-4 4-5 .... 9999-E4) how can we achieve O(log N) update time?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-309434 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-309434 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-309434\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"310847\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/my_new_handle\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/233736/avatar/24128c61b65e3262.jpg'/> </a>\n <div><a href=\"/profile/my_new_handle\" title=\"Candidate Master my_new_handle\" class=\"rated-user user-violet\">my_new_handle</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/20/2016 14:49\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-310847\" href=\"?#comment-310847\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"310847\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"233736\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-310847\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>а зачем в таске б массив он влияет как-то?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-310847 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-310847 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-310847\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"332763\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/rhezo\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/305605/avatar/aa59e9c2ec688c6a.jpg'/> </a>\n <div><a href=\"/profile/rhezo\" title=\"Candidate Master rhezo\" class=\"rated-user user-violet\">rhezo</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Dec/24/2016 07:56\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-332763\" href=\"?#comment-332763\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"332763\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"305605\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-332763\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I'm getting Runtime Error on test 44 in <a href=\"//codeforces.com/problemset/problem/383/C\">Propogating Tree</a>. </p><p>This is because of stack overflow right? That test has N = 2e5 and for a straight chain of nodes, I'll get a runtime error with a recursive DFS right? What to do in such cases? </p><p>I can write an iterative DFS, but I do HLD recursively too and I'm not quite sure if I can write an iterative HLD. </p><p>Can anyone tell me what to do in such cases? I'm assuming that I got the runtime error due to stackoverflow from DFS.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-332763 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-332763 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-332763\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"346070\" commentParentId=\"332763\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/yinanzhu\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/520731/avatar/d61a58bf5df54146.jpg'/> </a>\n <div><a href=\"/profile/yinanzhu\" title=\"Expert yinanzhu\" class=\"rated-user user-blue\">yinanzhu</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/26/2017 07:18\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-346070\" href=\"?#comment-346070\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-332763\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"346070\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"520731\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-346070\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I used recursive dfs and passed all test case. Test 44 cost 1.5 s</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-346070 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-346070 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-346070\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"387028\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/blue__legend\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/blue__legend\" title=\"Expert blue__legend\" class=\"rated-user user-blue\">blue__legend</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/23/2017 07:16\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-387028\" href=\"?#comment-387028\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"387028\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"284949\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-387028\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>How to solve DIV 1 C using one fenwick or segment tree. The code link given in editorial is not working.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-387028 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-387028 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-387028\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"757423\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Ausmosian\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Ausmosian\" title=\"Expert Ausmosian\" class=\"rated-user user-blue\">Ausmosian</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/05/2021 15:05\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-757423\" href=\"?#comment-757423\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"757423\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"727283\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-757423\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>[<a href=\"https://codeforces.com/contest/383/problem/C\">384E — Propagating tree</a>] Can also be solved using Square Root Decomposition. <a href=\"https://codeforces.com/contest/383/submission/106526543\">Submission</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-757423 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-757423 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-757423\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"838255\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/3hill\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1621900/avatar/478297db63bad207.jpg'/> </a>\n <div><a href=\"/profile/3hill\" title=\"Expert 3hill\" class=\"rated-user user-blue\">3hill</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/11/2021 17:02\">2 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-838255\" href=\"?#comment-838255\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"838255\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1621900\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-838255\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I am Getting MLE on TC-53<br />Can someone review my code and figure out the issue ,Thanks</p> <ul> <li><a href=\"https://codeforces.com/contest/383/problem/C\">Problem</a></li> <li><a href=\"https://codeforces.com/contest/383/submission/128510633\">My code</a></li> </ul></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-838255 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-838255 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-838255\">\r\n </ul>\r\n</div>\r\n <br/>\r\n\r\n<div id=\"editBox-10547\" style=\"width:50em;display:none;\">\r\n <div class=\"previewBody\" style=\"border: 1px solid #d4d4d4; margin-bottom: 0.5em; padding: 0.25em; display:none;\"> </div>\r\n <div style=\"width: 1px\"> </div>\r\n <div class=\"commentLocale\" style=\"position: relative; top: 0.5em;left:4px;display: none;\">\r\n <input type=\"radio\" name=\"locale\" value=\"en\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In English</span>\r\n <input style=\"margin-left:1em\" type=\"radio\" name=\"locale\" value=\"ru\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In Russian</span>\r\n </div>\r\n <textarea data-drafts-id=\"CommentReplyFrame\" class=\"wysiwyg\" name=\"editContent\" rows=\"20\" style=\"width:99%;\"></textarea>\r\n <div class=\"error error__content\"></div>\r\n <div style=\"text-align:center;\">\r\n <input type=\"button\" name=\"preview\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Preview\"/>\r\n <input type=\"button\" name=\"save\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Save\"/>\r\n </div>\r\n</div>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n\r\nvar firstPreview10547 = true;\r\nvar lastPreviewContent10547 = '';\r\n\r\nif (!window.moveCommentRevision) {\r\n moveCommentRevision = function(e, dir) {\r\n var p = e.parent();\r\n var revisionCount = parseInt(p.attr(\"revisionCount\"));\r\n var revision = parseInt(p.attr(\"revision\"));\r\n var next = revision + dir;\r\n var commentId = p.attr(\"commentId\");\r\n if (next >= 1 && next <= revisionCount) {\r\n $.post(\r\n \"/data/comment-data\",\r\n {action: \"revision\", commentId: commentId, revision: next},\r\n function(json) {\r\n if (json.success == \"true\") {\r\n var parentDiv = e;\r\n\r\n while (parentDiv !== null && (parentDiv[0].nodeName.toLowerCase() !== \"td\" || !parentDiv.hasClass(\"right\"))) {\r\n parentDiv = parentDiv.parent();\r\n }\r\n\r\n if (parentDiv === null) {\r\n return;\r\n }\r\n\r\n parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\").html(json.content);\r\n Codeforces.setupSpoilers(parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\"));\r\n p.attr(\"revision\", next);\r\n p.find(\"span.revision\").text(next);\r\n if (next == 1) {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"visible\");\r\n }\r\n if (next == revisionCount) {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"visible\");\r\n }\r\n\r\n window.updateTypography();\r\n MathJax.Hub.Typeset();\r\n } else {\r\n alert(e.error);\r\n }\r\n },\r\n \"json\"\r\n );\r\n }\r\n };\r\n}\r\n\r\n$(\"div[commentableId=10547] a.leftRevision\").click(function () {\r\n window.moveCommentRevision($(this), -1);\r\n return false;\r\n});\r\n\r\n$(\"div[commentableId=10547] a.rightRevision\").click(function () {\r\n window.moveCommentRevision($(this), +1);\r\n return false;\r\n});\r\n\r\n\r\n\r\n });\n </script>\n\r\n\r\n <script src=\"//codeforces.org/s/81027/js/swfobject-2.2.min.js\" type=\"text/javascript\"></script>\n <script src=\"//codeforces.org/s/81027/js/ftaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n if (window.evercookie) {\n var ec = new evercookie({\n history: false,\n silverlight: false,\n baseurl: '',\n asseturi: '/assets',\n phpuri: '/2fdcd78',\n pngPath: '/eps',\n etagPath: '/ees',\n cachePath: '/ecs'\n });\n\n var randomNumber = function () {\n return Math.random().toString(36).substr(2);\n };\n\n var randomToken = function () {\n return (randomNumber() + randomNumber()).substring(0, 18);\n };\n\n window._ftaa = \"\";\n\n ec.get(\"70a7c28f3de\", function (value) {\n window._ftaa = value;\n if (!window._ftaa) {\n window._ftaa = randomToken();\n ec.set(\"70a7c28f3de\", window._ftaa);\n }\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n } else {\n window._ftaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\n <script src=\"//codeforces.org/s/81027/js/bfaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n var fpCallback = function() {\n Fingerprint2.get({}, function(components) {\n window._bfaa = Fingerprint2.x64hash128(components.map(function (pair) { return pair.value }).join(), 31);\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n };\n if (typeof Fingerprint2 !== 'undefined') {\n if (window.requestIdleCallback) {\n requestIdleCallback(fpCallback)\n } else {\n setTimeout(fpCallback, 500)\n }\n } else {\n window._bfaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"a.new-root-comment\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n\r\n $(\".comment-table .reply a\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".vote-for-comment\").mouseover(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").mouseout(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").click(function () {\r\n var vote = $(this);\r\n var commentId = $(this).parent().attr(\"commentid\");\r\n var commentRating = $(this).parent().attr(\"data-commentRating\");\r\n var direction = $(this).attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n $.post(\"/data/comment/vote\", {commentId: commentId, _tta: Codeforces.tta(), vote: direction, commentRating: commentRating}, function(data) {\r\n if (direction != 0 && !ownComment && data[\"success\"] == \"true\") {\r\n vote.parent().find(\".vote-for-comment\").attr(\"voteDirection\", 0);\r\n if (direction == 1)\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n else {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.closest(\".CommentVoteFrame\").find(\".ComplaintFrame\").css(\"display\", \"inline-block\");\r\n }\r\n vote.find(\"img\").attr(\"popacity\", \"1.0\");\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n vote.parent().find(\".commentRating\").html(data[\"commentRating\"]);\r\n }\r\n Codeforces.showMessage(data[\"message\"]);\r\n }, \"json\");\r\n return false;\r\n });\r\n\r\n $(\".negative-comment-vote\").closest(\".comment-table\").addClass(\"comment-bad\");\r\n\r\n $(\".troll-comment-vote\").closest(\".comment\").css(\"display\", \"none\");\r\n\r\n $(\".too-negative-comment-vote\").closest(\".comment-table\").each(function () {\r\n var e = $(this);\r\n e.addClass(\"comment-too-bad\");\r\n var commentId = e.attr(\"commentId\");\r\n $(\"<div class='bad-comment-replacement ttypography'>The comment is hidden because of too negative feedback, click <a href=# class=show-bad-comment-link>here</a> to view it</div>\").appendTo(\r\n e.find(\".right\")\r\n );\r\n e.find(\".comment-content\").hide();\r\n e.find(\".show-bad-comment-link\").click(function () {\r\n e.find(\".comment-content\").show();\r\n e.find(\".bad-comment-replacement\").hide();\r\n return false;\r\n });\r\n });\r\n });\n </script>\n </div>\r\n\r\n <style type=\"text/css\">\r\n .new-comments-box {\r\n padding: 0.5em;\r\n width: 22px;\r\n font-size: 1.3rem;\r\n font-weight: bold !important;\r\n\r\n position: fixed;\r\n top: 40%;\r\n right: 0;\r\n opacity: 0.2;\r\n color: white;\r\n text-align: center;\r\n\r\n border: 1px solid #222;\r\n background-color: #888 !important;\r\n border-radius: 3px;\r\n -moz-border-radius: 3px;\r\n -webkit-border-radius: 3px;\r\n }\r\n\r\n .new-comments-box:hover {\r\n opacity: 1;\r\n }\r\n\r\n .new-comments-box .dir:hover {\r\n background: #3B5998 !important;\r\n cursor: pointer;\r\n }\r\n </style>\r\n\r\n <div class=\"new-comments-box\" data-position=\"outside\" data-index=\"-1\" style=\"display: none;\">\r\n <div class=\"up dir\" title=\"Ctrl+Up\">↑<hr/>\r\n </div>\r\n <div class=\"info\" title=\"New comments\"></div>\r\n <div class=\"down dir\" title=\"Ctrl+Down\">\r\n <hr/>↓\r\n </div>\r\n </div>\r\n\r\n <script>\r\n $(\".show-archived-checkbox\").change(function () {\r\n const checked = $(this).is(\":checked\");\r\n $.post(\"/data/comment-data\", {action: \"setShowArchived\", checked}, function (json) {\r\n if (json[\"success\"] !== \"true\") {\r\n alert(json[\"error\"]);\r\n } else {\r\n if (checked) {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are now displayed\")\r\n } else {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are no longer displayed\")\r\n }\r\n }\r\n });\r\n return false;\r\n });\r\n\r\n function gotoComment(direction) {\r\n var box = $(\".new-comments-box\");\r\n var index = parseInt(box.attr(\"data-index\"));\r\n if (index == -1)\r\n index = 0;\r\n else\r\n index = Math.max(0, Math.min(parseInt(box.find(\".info\").text()) - 1, index + direction));\r\n box.attr(\"data-index\", index);\r\n var comment = $($(\".comment .highlight-blue[commentId]\").get(index));\r\n $('html, body').animate({\r\n 'scrollTop': Math.max(0, comment.offset().top - ($(window).height() - comment.height()) / 2)\r\n });\r\n return false;\r\n }\r\n\r\n $(\".new-comments-box .down\").click(function () {\r\n return gotoComment(1);\r\n });\r\n\r\n $(\".new-comments-box .up\").click(function () {\r\n return gotoComment(-1);\r\n });\r\n\r\n $(document).keydown(function (e) {\r\n var code = (e.keyCode ? e.keyCode : e.which);\r\n if (e.ctrlKey) {\r\n if (code == 38 || code == 40) {\r\n gotoComment(code - 39);\r\n }\r\n }\r\n });\r\n\r\n var newCommentCount = $(\".comment .highlight-blue[commentId]\").length;\r\n if (newCommentCount > 0) {\r\n $(\".new-comments-box .info\").text(newCommentCount);\r\n $(\".new-comments-box\").show();\r\n }\r\n\r\n $('table.comment-table').mouseenter(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").addClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n\r\n $('table.comment-table').mouseleave(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").removeClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n </script>\r\n\r\n\r\n\r\n <script>\r\n function adjustTopicComplainFrames() {\r\n let topicIds = [];\r\n\r\n $(\".has-topic-id\").each(function () {\r\n const $this = $(this);\r\n const topicId = $this.attr(\"topicId\");\r\n if (topicId) {\r\n topicIds.push(topicId);\r\n }\r\n });\r\n\r\n $.post(\"/data/topics\", {\r\n action: \"findComplainableTopicIds\",\r\n topicIds: topicIds.join(\",\")\r\n }, function (json) {\r\n if (json[\"success\"] === \"true\") {\r\n for (const topicId of json[\"complainableTopicIds\"].split(\",\")) {\r\n $(\".has-topic-id[topicId=\" + topicId + \"]\").each(function () {\r\n $(this).find(\".meta .ComplaintFrame\").css(\"display\", \"inline-block\");\r\n });\r\n }\r\n }\r\n }, \"json\");\r\n }\r\n\r\n $(function () {\r\n adjustTopicComplainFrames();\r\n })\r\n </script>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-10531\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 10531, _tta: Codeforces.tta(), topicRevisionId: 36233, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-10531\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 10531, _tta: Codeforces.tta(), topicRevisionId: 36233, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n </div>\r\n </div>\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 22:13:02</span> (h1).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/81027/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/81027/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/81027/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/81027/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-81027.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'81287584a8369d92',t:'MTY5NjcwNTk4Mi42NDcwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"}}},{"rowIdx":1938,"cells":{"problem_id":{"kind":"string","value":"383E"},"contest":{"kind":"string","value":"383"},"problem":{"kind":"string","value":"E"},"lang":{"kind":"string","value":"en"},"problem_title":{"kind":"string","value":"E. Vowels"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">E. Vowels</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>4 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Iahubina is tired of so many complicated languages, so she decided to invent a new, simple language. She already made a dictionary consisting of <span class=\"tex-span\"><i>n</i></span> 3-words. A 3-word is a sequence of exactly <span class=\"tex-span\">3</span> lowercase letters of the first 24 letters of the English alphabet (<span class=\"tex-span\"><i>a</i></span> to <span class=\"tex-span\"><i>x</i></span>). She decided that some of the letters are vowels, and all the others are consonants. The whole language is based on a simple rule: any word that contains at least one vowel is <span class=\"tex-font-style-it\">correct</span>.</p><p>Iahubina forgot which letters are the vowels, and wants to find some possible correct sets of vowels. She asks Iahub questions. In each question, she will give Iahub a set of letters considered vowels (in this question). For each question she wants to know how many words of the dictionary are correct, considering the given set of vowels.</p><p>Iahubina wants to know the <span class=\"tex-span\"><i>xor</i></span> of the squared answers to all the possible questions. There are <span class=\"tex-span\">2<sup class=\"upper-index\">24</sup></span> different questions, they are all subsets of the set of the first 24 letters of the English alphabet. Help Iahub find that number.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains one integer, <span class=\"tex-span\"><i>n</i></span> <span class=\"tex-span\">(1 ≤ <i>n</i> ≤ 10<sup class=\"upper-index\">4</sup>)</span>. Each of the next <span class=\"tex-span\"><i>n</i></span> lines contains a 3-word consisting of <span class=\"tex-span\">3</span> lowercase letters. There will be no two identical 3-words.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print one number, the <span class=\"tex-span\"><i>xor</i></span> of the squared answers to the queries.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>5<br/>abc<br/>aaa<br/>ada<br/>bcd<br/>def<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>0<br/></pre></div></div></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"7461abaf5f314d9343f72e91785c82ae\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - E - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"f2f8284d26a4a4d6b4f15082f9e1ab3f212e9edd\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - E - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/73366/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/73366/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/73366/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/73366/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/73366/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/73366/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/73366/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/73366/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/73366/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/73366/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/73366/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/73366/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/73366/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/73366/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/sidebar-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/a037fe51637846d9c7c725713cd840ea/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='7461abaf5f314d9343f72e91785c82ae'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/73366/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/73366/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fcontest%2F383%2Fproblem%2FE%3Flocale%3Den\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"current\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='7461abaf5f314d9343f72e91785c82ae'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:100%;\"><a style=\"color: black\" href=\"/contest/383\">Codeforces Round 225 (Div. 1)</a></th>\n </tr>\n <tr>\n <td class=\"left bottom\" colspan=\"1\"><span class=\"contest-state-phase\">Finished</span></td>\n </tr>\n </tbody>\n </table>\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Practice?\n <div class=\"top-links\">\n </div>\n </div>\n<div>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Want to solve the contest problems after the official contest ends? Just register for practice and you will be able to submit solutions.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"\" method=\"post\"><input type='hidden' name='csrf_token' value='7461abaf5f314d9343f72e91785c82ae'/>\r\n <input type=\"hidden\" name=\"action\" value=\"registerForPractice\"/>\r\n <input type=\"submit\" name=\"submit\" value=\"Register for practice\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div> \r\n</div>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox ContestVirtualFrame borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Virtual participation <i class=\"sidebar-caption-icon las la-angle-down\"></i>\r\n\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\" \"\r\n\r\n data-page-url=\"/data/sidebarFrames\"\r\n\r\n>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests.\n\nIf you've seen these problems, a virtual contest is not for you - solve these problems in the archive.\n\nIf you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.\n\nNever use someone else's code, read the tutorials or communicate with other person during a virtual contest.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"/contest/383/virtual\" method=\"get\">\r\n <input type=\"submit\" name=\"submit\" value=\"Start virtual contest\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div>\r\n</div>\r\n <script>\r\n $(function () {\r\n $(\".ContestVirtualFrame .sidebar-caption-icon\").click(function() {\r\n $(this).toggleClass(\"la-angle-down la-angle-right\");\r\n const $target = $(this).parent().next();\r\n $target.toggle();\r\n const dataPageUrl = $target.attr(\"data-page-url\");\r\n const collapsed = $(this).hasClass(\"la-angle-right\");\r\n const params = {\r\n action: \"setCollapsed\",\r\n sidebarFrameSimpleClassName: \"ContestVirtualFrame\",\r\n collapsed\r\n };\r\n $.each($target[0].attributes, function(i, a) {\r\n const name = a.name;\r\n if (name.startsWith(\"data-extra-key-\")) {\r\n const key = a.value;\r\n const keyIndex = parseInt(name.substring(\"data-extra-key-\".length));\r\n const value = $target.attr(\"data-extra-value-\" + keyIndex);\r\n params[key] = value;\r\n }\r\n });\r\n $.post(dataPageUrl, params, function (result) {\r\n if (result[\"success\"] !== \"true\") {\r\n Codeforces.showMessage(\"Failed to save collapsed state.\");\r\n }\r\n }, \"json\");\r\n return false;\r\n });\r\n })\r\n </script>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Problem tags\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Combinatorics\">\r\n combinatorics\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Divide and Conquer\">\r\n divide and conquer\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Dynamic programming\">\r\n dp\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Difficulty\">\r\n *2700\r\n</span>\r\n </div>\n <div style=\"clear:both;text-align:right;font-size:1.1rem;\">\r\n <span title=\"Please login into the Codeforces\" class=\"notice\">No tag edit access</span>\r\n </div>\r\n</div>\r\n </div>\n\r\n<form id=\"addTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='7461abaf5f314d9343f72e91785c82ae'/>\r\n <input name=\"action\" type=\"hidden\" value=\"addTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"5726\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<form id=\"removeTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='7461abaf5f314d9343f72e91785c82ae'/>\r\n <input name=\"action\" type=\"hidden\" value=\"removeTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"5726\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<script type=\"text/javascript\">\r\n $(\".tag-box img\").click(function () {\r\n var tagName = $(this).attr(\"value\");\r\n Codeforces.confirm(\"Are you sure you want to remove this tag?\", function () {\r\n $(\"#removeTagForm input[name=tagName]\").val(tagName);\r\n $(\"#removeTagForm\").submit();\r\n }, function () {\r\n }, \"Yes\", \"No\");\r\n });\r\n\r\n $(\"#addTagLink\").click(function () {\r\n $(this).hide();\r\n $(\"#addTagLabel\").show();\r\n return false;\r\n });\r\n\r\n $(\"#addTagSelect\").change(function () {\r\n var tagName = $(this).val();\r\n if (tagName === \"\") {\r\n $(\"#addTagLabel\").hide();\r\n $(\"#addTagLink\").show();\r\n } else {\r\n $(\"#addTagForm input[name=tagName]\").val(tagName);\r\n $(\"#addTagForm\").submit();\r\n }\r\n });\r\n</script>\r\n\r\n<style type=\"text/css\">\r\n#new-resource-form tr td {\r\npadding-top: 0.5em;\r\n}\r\n#new-resource-form input:not([type=\"submit\"]) {\r\nfont-size: 0.8em;\r\n}\r\n#new-resource-form select {\r\nfont-size: 0.8em;\r\n}\r\n.new-resource-error {\r\nfont-size: 0.8em;\r\n}\r\n.resource-locale {\r\ncolor: #666;\r\nfont-family: Consolas, \"Andale Mono WT\", \"Andale Mono\", \"Lucida Console\", \"Lucida Sans Typewriter\", \"DejaVu Sans Mono\", \"Bitstream Vera Sans Mono\", \"Liberation Mono\", \"Nimbus Mono L\", Monaco, \"Courier New\", Courier, monospace;\r\n}\r\n</style>\r\n<div class=\"roundbox sidebox sidebar-menu borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Contest materials\n<div class=\"top-links\">\n</div>\n</div>\n<ul>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/10448\" title=\"Codeforces Round #225\" target=\"_blank\">Codeforces Round #225</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"2166:2167\" resourceName=\"Announcement\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n<li>\r\n<span>\r\n<a href=\"https://codeforces.com/blog/entry/10476\" title=\"Tutorial\" target=\"_blank\">Tutorial <span class=\"resource-locale\">(en)</span></a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"2170\" resourceName=\"Tutorial\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n</ul>\r\n</div></div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li class=\"current selectedLava\"><a\r\n href=\"/contest/383\">Problems</a></li>\r\n <li><a\r\n href=\"/contest/383/submit\">Submit Code</a></li>\r\n <li><a\r\n href=\"/contest/383/my\">My Submissions</a></li>\r\n <li><a\r\n href=\"/contest/383/status\">Status</a></li>\r\n <li><a\r\n href=\"/contest/383/hacks\">Hacks</a></li>\r\n <li><a\r\n href=\"/contest/383/room/1\">Room</a></li>\r\n <li><a\r\n href=\"/contest/383/standings\">Standings</a></li>\r\n <li><a\r\n href=\"/contest/383/customtest\">Custom Invocation</a></li>\r\n</ul>\r\n</div>\n\r\n <style>\r\n #facebox .content:has(.diff-popup) {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n }\r\n\r\n .testCaseMarker {\r\n position: absolute;\r\n font-weight: bold;\r\n font-size: 1rem;\r\n }\r\n\r\n .diff-popup {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n display: none;\r\n overflow: auto;\r\n }\r\n\r\n .input-output-copier {\r\n font-size: 1.2rem;\r\n float: right;\r\n color: #888 !important;\r\n cursor: pointer;\r\n border: 1px solid rgb(185, 185, 185);\r\n padding: 3px;\r\n margin: 1px;\r\n line-height: 1.1rem;\r\n text-transform: none;\r\n }\r\n\r\n .input-output-copier:hover {\r\n background-color: #def;\r\n }\r\n\r\n .test-explanation textarea {\r\n width: 100%;\r\n height: 1.5em;\r\n }\r\n\r\n .pending-submission-message {\r\n color: darkorange !important;\r\n }\r\n </style>\r\n <script>\r\n const OPENING_SPACE = String.fromCharCode(1001);\r\n const CLOSING_SPACE = String.fromCharCode(1002);\r\n\r\n const nodeToText = function (node, pre) {\r\n let result = [];\r\n\r\n if (node.tagName === \"SCRIPT\" || node.tagName === \"math\"\r\n || (node.classList && node.classList.contains(\"input-output-copier\")))\r\n return [];\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(OPENING_SPACE);\r\n }\r\n\r\n if (node.nodeType === Node.TEXT_NODE) {\r\n let s = node.textContent;\r\n if (!pre) {\r\n s = s.replace(/\\s+/g, \" \");\r\n }\r\n if (s.length > 0) {\r\n result.push(s);\r\n }\r\n }\r\n\r\n if (pre && node.tagName === \"BR\") {\r\n result.push(\"\\n\");\r\n }\r\n\r\n node.childNodes.forEach(function (child) {\r\n result.push(nodeToText(child, node.tagName === \"PRE\").join(\"\"));\r\n });\r\n\r\n if (node.tagName === \"DIV\"\r\n || node.tagName === \"P\"\r\n || node.tagName === \"PRE\"\r\n || node.tagName === \"UL\"\r\n || node.tagName === \"LI\"\r\n ) {\r\n result.push(\"\\n\");\r\n }\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(CLOSING_SPACE);\r\n }\r\n\r\n return result;\r\n }\r\n\r\n const isSpecial = function (c) {\r\n return c === ',' || c === '.' || c === ';' || c === ')' || c === ' ';\r\n }\r\n\r\n const convertStatementToText = function(statmentNode) {\r\n const text = nodeToText(statmentNode, false).join(\"\").replace(/ +/g, \" \").replace(/\\n\\n+/g, \"\\n\\n\");\r\n let result = [];\r\n for (let i = 0; i < text.length; i++) {\r\n const c = text.charAt(i);\r\n if (c === OPENING_SPACE) {\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"E\" data-uuid=\"ps_eb3dd8303cc71c385b9e964a9e81b93721095ef6\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">E. Vowels</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>4 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Iahubina is tired of so many complicated languages, so she decided to invent a new, simple language. She already made a dictionary consisting of <span class=\"tex-span\"><i>n</i></span> 3-words. A 3-word is a sequence of exactly <span class=\"tex-span\">3</span> lowercase letters of the first 24 letters of the English alphabet (<span class=\"tex-span\"><i>a</i></span> to <span class=\"tex-span\"><i>x</i></span>). She decided that some of the letters are vowels, and all the others are consonants. The whole language is based on a simple rule: any word that contains at least one vowel is <span class=\"tex-font-style-it\">correct</span>.</p><p>Iahubina forgot which letters are the vowels, and wants to find some possible correct sets of vowels. She asks Iahub questions. In each question, she will give Iahub a set of letters considered vowels (in this question). For each question she wants to know how many words of the dictionary are correct, considering the given set of vowels.</p><p>Iahubina wants to know the <span class=\"tex-span\"><i>xor</i></span> of the squared answers to all the possible questions. There are <span class=\"tex-span\">2<sup class=\"upper-index\">24</sup></span> different questions, they are all subsets of the set of the first 24 letters of the English alphabet. Help Iahub find that number.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains one integer, <span class=\"tex-span\"><i>n</i></span> <span class=\"tex-span\">(1 ≤ <i>n</i> ≤ 10<sup class=\"upper-index\">4</sup>)</span>. Each of the next <span class=\"tex-span\"><i>n</i></span> lines contains a 3-word consisting of <span class=\"tex-span\">3</span> lowercase letters. There will be no two identical 3-words.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print one number, the <span class=\"tex-span\"><i>xor</i></span> of the squared answers to the queries.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>5<br />abc<br />aaa<br />ada<br />bcd<br />def<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>0<br /></pre></div></div></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=E]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== statementText) {\r\n $problem.find(\".diff-notifier\").show();\r\n\r\n $problem.find(\".diff-notifier-close\").click(function() {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n $problem.find(\".diff-notifier\").hide();\r\n });\r\n\r\n $problem.find(\"a.view-changes\").click(function() {\r\n $.post(\"/data/diff\", {action: \"getDiff\", a: previousStatementText, b: statementText}, function (result) {\r\n if (result[\"success\"] === \"true\") {\r\n Codeforces.facebox(\".diff-popup\", \"//codeforces.org/s/73366\");\r\n $(\"#facebox .diff-popup\").html(result[\"diff\"]);\r\n }\r\n }, \"json\");\r\n });\r\n }\r\n } else {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n }\r\n });\r\n });\r\n </script>\r\n\r\n\r\n<script type=\"text/javascript\">\r\n $(document).ready(function () {\r\n window.changedTests = new Set();\r\n\r\n function endsWith(string, suffix) {\r\n return string.indexOf(suffix, string.length - suffix.length) !== -1;\r\n }\r\n\r\n const inputFileDiv = $(\"div.input-file\");\r\n const inputFile = inputFileDiv.text();\r\n const outputFileDiv = $(\"div.output-file\");\r\n const outputFile = outputFileDiv.text();\r\n\r\n\r\n if (!endsWith(inputFile, \"standard input\")\r\n && !endsWith(inputFile, \"standard input\")) {\r\n inputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n if (!endsWith(outputFile, \"standard output\")\r\n && !endsWith(outputFile, \"standard output\")) {\r\n outputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n const titleDiv = $(\"div.header div.title\");\r\n\r\n\r\n\r\n String.prototype.replaceAll = function (search, replace) {\r\n return this.split(search).join(replace);\r\n };\r\n\r\n $(\".sample-test .title\").each(function () {\r\n const preId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n const cpyId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n\r\n $(this).parent().find(\"pre\").attr(\"id\", preId);\r\n const $copy = $(\"<div title='Copy' data-clipboard-target='#\" + preId + \"' id='\" + cpyId + \"' class='input-output-copier'>Copy</div>\");\r\n $(this).append($copy);\r\n\r\n const clipboard = new Clipboard('#' + cpyId, {\r\n text: function (trigger) {\r\n const pre = document.querySelector('#' + preId);\r\n const lines = pre.querySelectorAll(\".test-example-line\");\r\n return Codeforces.filterClipboardText(pre.innerText, lines.length);\r\n }\r\n });\r\n\r\n const isInput = $(this).parent().hasClass(\"input\");\r\n\r\n clipboard.on('success', function (e) {\r\n if (isInput) {\r\n Codeforces.showMessage(\"The example input has been copied into the clipboard\");\r\n } else {\r\n Codeforces.showMessage(\"The example output has been copied into the clipboard\");\r\n }\r\n e.clearSelection();\r\n });\r\n });\r\n\r\n $(\".test-form-item input\").change(function () {\r\n addPendingSubmissionMessage($($(this).closest(\"form\")), \"You changed the answer, do not forget to submit it if you want to save the changes\");\r\n const index = $(this).closest(\".problemindexholder\").attr(\"problemindex\");\r\n let test = \"\";\r\n $(this).closest(\"form input\").each(function () {\r\n const test_ = $(this).attr(\"name\");\r\n if (test_ && test_.substring(0, 4) === \"test\") {\r\n test = test_;\r\n }\r\n });\r\n if (index.length > 0 && test.length > 0) {\r\n const indexTest = index + \"::\" + test;\r\n window.changedTests.add(indexTest);\r\n }\r\n });\r\n\r\n $(window).on('beforeunload', function () {\r\n if (window.changedTests.size > 0) {\r\n return 'Dialog text here';\r\n }\r\n });\r\n\r\n autosize($('.test-explanation textarea'));\r\n\r\n $(\".test-example-line\").hover(function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n let top = 1E20;\r\n let left = 1E20;\r\n let problem = $(this).closest(\".problemindexholder\");\r\n $(this).closest(\".input\").find(\".\" + clazz).css(\"background-color\", \"#FFFDE7\").each(function() {\r\n top = Math.min(top, $(this).offset().top);\r\n left = Math.min(left, $(this).offset().left);\r\n });\r\n let testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n if (testCaseMarker.length === 0) {\r\n const html = \"<div class=\\\"testCaseMarker testCaseMarker_\" + end + \" notice\\\"></div>\";\r\n problem.append($(html));\r\n testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n }\r\n if (testCaseMarker) {\r\n testCaseMarker.show()\r\n .offset({top, left: left - 20})\r\n .text(end);\r\n }\r\n }\r\n }\r\n });\r\n }, function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n $(\".\" + clazz).css(\"background-color\", \"\");\r\n $(this).closest(\".problemindexholder\").find(\".testCaseMarker_\" + end).hide();\r\n }\r\n }\r\n });\r\n });\r\n\r\n });\r\n</script>\r\n\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 05:38:02</span> (j3).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/73366/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/73366/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/73366/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/73366/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-73366.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'8122c401d9cf9d52',t:'MTY5NjY0NjI4Mi42MjQwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"},"long_tags":{"kind":"string","value":"[\"Combinatorics\", \"Divide and Conquer\", \"Dynamic programming\"]"},"short_tags":{"kind":"string","value":"[\"combinatorics\", \"divide and conquer\", \"dp\", \"*2700\"]"},"tutorial_link":{"kind":"string","value":"https://codeforces.com/blog/entry/10476"},"tutorial_page":{"kind":"string","value":"\r\n\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"4f4c31ed5807bbee2a02378cf0944c06\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"h1\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Codeforces Round #225 — Editorial - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n \n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Codeforces Round #225 — Editorial - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/81027/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/81027/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/81027/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/81027/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/81027/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/81027/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/81027/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/81027/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/81027/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/81027/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/81027/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/81027/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/81027/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/81027/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/573cedc6b04c15481941f418269f4057/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='4f4c31ed5807bbee2a02378cf0944c06'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/81027/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fblog%2Fentry%2F10476\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='4f4c31ed5807bbee2a02378cf0944c06'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Pay attention\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n <div style=\"text-align:center;border-bottom: 1px solid rgb(185, 185, 185);margin:0 -0.5em 0.5em -0.5em;padding: 0 1em 0.5em 1em;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 1, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:51:58</span><br/><a href=\"/contestRegistration/1876\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n <div style=\"text-align:center;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 2, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:51:58</span><br/><a href=\"/contestRegistration/1877\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n\r\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div>\r\n\r\n\n <div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\n\r\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='4f4c31ed5807bbee2a02378cf0944c06'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n </label>\r\n </div>\r\n <div style=\"padding: 0 1em 1em 1em;text-align:right;\">\r\n <input style=\"height:1.65em;padding:0 0.75em;\" type=\"submit\" value=\"Find\"/>\r\n </div>\r\n </form>\r\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".handleBox\").autocomplete(\"/data/handles\", {\r\n delay: 200,\r\n width: 200,\r\n selectFirst: false,\r\n matchContains: true,\r\n minChars: 3\r\n });\r\n $(\".handleForm\").attr(\"autocomplete\", \"off\").submit(function () {\r\n var link = \"/profile/userHandle\".replace(\r\n \"userHandle\", $(this).find(\".handleBox\").val()\r\n );\r\n window.location = link;\r\n return false;\r\n });\r\n });\n </script>\n\r\n\r\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Recent actions\n <div class=\"top-links\">\n </div>\n </div>\n <div class=\"recent-actions\">\r\n <ul>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/121073\">Meta Hacker Cup 2023 Round 1</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/.Danet\" title=\"Expert .Danet\" class=\"rated-user user-blue\">.Danet</a> →\r\n <a href=\"/blog/entry/121172\">[TLE on pretest1]</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\" class=\"rated-user user-red\">Pyqe</a> →\r\n <a href=\"/blog/entry/121025\">Codeforces Round #902 (Div. 1, Div. 2, based on COMPFEST 15 — Final Round)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pranshu_Pandya\" title=\"Specialist Pranshu_Pandya\" class=\"rated-user user-cyan\">Pranshu_Pandya</a> →\r\n <a href=\"/blog/entry/121171\">An Interesting Tree Problem</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/sszcdjr\" title=\"Master sszcdjr\" class=\"rated-user user-orange\">sszcdjr</a> →\r\n <a href=\"/blog/entry/119859\">Codeforces Round 896 (Div. 1, Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/119880\">It's Happening! Meta Hacker Cup 2023 Schedule</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/DaviddeGea1\" title=\"Expert DaviddeGea1\" class=\"rated-user user-blue\">DaviddeGea1</a> →\r\n <a href=\"/blog/entry/70917\">Number of ways of dividing an array into 2 parts such that sum of each part is > k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bekh\" title=\"Master Bekh\" class=\"rated-user user-orange\">Bekh</a> →\r\n <a href=\"/blog/entry/74245\">Questions and doubts regarding Aliens DP trick</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a> →\r\n <a href=\"/blog/entry/8192\">Codeforces Round #190 — Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/hocky\" title=\"Candidate Master hocky\" class=\"rated-user user-violet\">hocky</a> →\r\n <a href=\"/blog/entry/95323\">FBHC wuining uw Day? Incwease uw stacc size! (ㅅ´ ˘ `)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/liouzhou_101\" title=\"International Master liouzhou_101\" class=\"rated-user user-orange\">liouzhou_101</a> →\r\n <a href=\"/blog/entry/87598\">Editorial of Codeforces Round #700</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/yeon_gist\" title=\"Newbie yeon_gist\" class=\"rated-user user-gray\">yeon_gist</a> →\r\n <a href=\"/blog/entry/121170\">plusMinusPermutation computing error</a>\r\n <img alt=\"Text created or updated\" title=\"Text created or updated\" src=\"//codeforces.org/s/81027/images/icons/x-update-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/altforminuscontribution\" title=\"Newbie altforminuscontribution\" class=\"rated-user user-gray\">altforminuscontribution</a> →\r\n <a href=\"/blog/entry/121162\">My screen get unexpectedly big, what should I do</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/atcoder_official\" title=\"Unrated, atcoder_official\" class=\"rated-user user-black\">atcoder_official</a> →\r\n <a href=\"/blog/entry/121120\">We will hold UNIQUE VISION Programming Contest 2023 Autumn(AtCoder Beginner Contest 323)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/YouStill_DontKnowMeYet\" title=\"Candidate Master YouStill_DontKnowMeYet\" class=\"rated-user user-violet\">YouStill_DontKnowMeYet</a> →\r\n <a href=\"/blog/entry/117659\">[GYM] Al-Baath Collegiate Programming Contest 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/ankancool\" title=\"Expert ankancool\" class=\"rated-user user-blue\">ankancool</a> →\r\n <a href=\"/blog/entry/121136\">Invitation to AstroByte 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/GeZhiyuan\" title=\"Grandmaster GeZhiyuan\" class=\"rated-user user-red\">GeZhiyuan</a> →\r\n <a href=\"/blog/entry/120943\">Codeforces Round 901 (Div. 1, Div. 2) Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a> →\r\n <a href=\"/blog/entry/120772\">PSA: Increase your stack size before the Meta Hacker Cup, here's how</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/dino_merlin\" title=\"Expert dino_merlin\" class=\"rated-user user-blue\">dino_merlin</a> →\r\n <a href=\"/blog/entry/121145\">Intuitive approach for CEOI Kangaroo?</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/icecuber\" title=\"Grandmaster icecuber\" class=\"rated-user user-red\">icecuber</a> →\r\n <a href=\"/blog/entry/70018\">CSES DP section editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bn00b\" title=\"Newbie Bn00b\" class=\"rated-user user-gray\">Bn00b</a> →\r\n <a href=\"/blog/entry/98820\">[FEATURE REQUEST : ATCODER] TOPICS TAGS AND SORTING BY SOLVE COUNT</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a> →\r\n <a href=\"/blog/entry/121163\">AtCoder Regular Contest 166 Announcement</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/windva\" title=\"Grandmaster windva\" class=\"rated-user user-red\">windva</a> →\r\n <a href=\"/blog/entry/120644\">Codeforces Round 899 (Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Misa-Misa\" title=\"Expert Misa-Misa\" class=\"rated-user user-blue\">Misa-Misa</a> →\r\n <a href=\"/blog/entry/121157\">Someone please help me understand this.</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/shivam565\" title=\"Specialist shivam565\" class=\"rated-user user-cyan\">shivam565</a> →\r\n <a href=\"/blog/entry/108348\">Total number of subarrays with sum atmost k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n </ul>\r\n </div>\r\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/recent-actions\">Detailed →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n</div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li><a\r\n href=\"/profile/fchirica\">fchirica</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/fchirica\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/fchirica\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/fchirica\">Submissions</a></li>\r\n <li><a\r\n href=\"/groups/with/fchirica\">Groups</a></li>\r\n <li><a\r\n href=\"/contests/with/fchirica\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/fchirica\">Problemsetting</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/fchirica\" style=\"text-decoration:none;color:black !important;\">fchirica's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"10531\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/10476\"> <p>Codeforces Round #225 — Editorial</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/fchirica\" title=\"Candidate Master fchirica\" class=\"rated-user user-violet\">fchirica</a>,\r\n <span class=\"format-humantime\" title=\"Jan/20/2014 22:18\">10 years ago</span>,\r\n \r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><h1><a href=\"/contest/384/problem/A\" title=\"Codeforces Round 225 (Div. 2)\">384A - Coder</a></h1><p>Usually, when you don’t have any idea how to approach a problem, a good try is to take some small examples.</p><p>So let’s see how it looks for N = 1, 2, 3, 4 and 5. With C I noted the coder and with * I noted an empty cell.</p><p><img alt=\" \" src=\"/predownloaded/8f/89/8f899efd227362957f283123a7927c7c8a300667.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>By now you should note that answer is N ^ 2 / 2 when N is even and (N ^ 2 + 1) / 2 when N is odd. Good. Generally, after you find a possible solution by taking examples, you need to prove it, then you can code it.</p><p>In order to proof it, one needs to do following steps:</p><p>1/ prove you can always build a solution having N ^ 2 / 2 (or (N ^ 2 + 1) / 2) pieces.</p><p>2/ prove that N ^ 2 / 2 (or (N ^ 2 + 1) / 2) is maximal number – no other bigger solution can be obtained.</p><p>For proof 1/ imagine you do coloring like in a chess table.</p><p><img alt=\" \" src=\"/predownloaded/50/12/50120d92bd0cea3d6a434d09ab4754ea20342351.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>The key observation is that by placing all coders on black squares of table, no two coders will attack. Why? Because a piece placed at a black square can attack only a piece placed at a white square. Again, why? Suppose chess table is 1-based. Then, a square (i, j) is black if and only if i + j is even. A piece placed at (i, j) can attack (i + 1, j), (i – 1, j) (i, j + 1) or (i, j – 1). The sum of those cells is i + j + 1 or i + j – 1. But since i + j is even, i + j + 1 and i + j – 1 are odd, hence white cells.</p><p>Depending on parity of N, number of black cells is either N ^ 2 / 2 or (N ^ 2 + 1) / 2. For N even, one can observe that there are equal amount of black and white cells. Total number of cells is N ^ 2, so number of black cells is N ^ 2 / 2. For N odd, number of black cells is number of white cells + 1. We can imaginary add a white cell to the board. Now, number of black cells will be also equal to number of white cells, so answer is (N ^ 2 + 1) / 2.</p><p>2/ Two coders attack each other if they are placed at two adjacent cells, one black and other one white. One needs to prove that adding more than number from 1/ will cause this to happen. If you place a coder at a white cell, you won’t be able to place at least one coder at a black cell, so in best case you don’t win anything by doing this. Hence, it’s optimally to place all coders on same color cells. Since cells colored in black are always more or equal to white ones, it’s always optimally to choose black color. But number from 1/ is the number of cells having black color. Adding one more piece will force you to add it to a white color cell. Now, you’ll have a piece placed at a black colored cell and one placed at an adjacent white colored cell, so two coders will attack. Hence, we can’t place more than number from 1/ pieces.</p><p>Code: <a href=\"http://pastie.org/8651801\">http://pastie.org/8651801</a></p><h1><a href=\"/contest/384/problem/B\" title=\"Codeforces Round 225 (Div. 2)\">384B - Multitasking</a></h1><p>Let’s start by saying when array A[] is sorted:</p><p>1/ is sorted in ascending order when i < j and A[i] <= A[j]. It is NOT sorted when i < j and A[i] > A[j].</p><p>2/ is sorted in descending order when i > j and A[i] <= A[j]. It is NOT sorted when i > j and A[i] > A[j].</p><p>Iahub can choose 2 indices i, j and swap values when A[i] > A[j]. If A[i] <= A[j], he’ll ignore operation. Hence, if he wants to sort all arrays in ascending order, he chooses indices i, j when i < j and perform operation. Otherwise, in all his operations he uses indices i, j such as i > j. A “good” operation is when choosing indices i < j for ascending order sorting and i > j for descending order sorting. By doing only good operations, after an array is sorted, it will stay sorted forever (for a sorted array, all good operations will be ignored).</p><p>From here we get our first idea: use any sorting algorithm you know and sort each array individually. When print swaps done by sorting algorithm chosen, print them as good operations. However, sorting each array individually can cause exceeding M * (M — 1) / 2 operations limit. Another possible solution would be, after you did an operation to an array, to update the operation to all arrays (you printed it, so it counts to M * (M — 1) / 2 operations limit; making it to all arrays will help sometimes and in worst case it won’t change anything). However, you need to code it very careful in order to make this algorithm pass the time limit. Doing this in a contest is not the best idea, especially when implementation could be complicated and you have no guarantee it will pass time limit.</p><p>So what else can we do? We can think out of box. Instead of sorting specific N arrays, you can sort all possible arrays of length M. Find a sequence of good operations such as, anyhow I’d choose an array of size M, it will get sorted ascending / descending.</p><p>I’ll show firstly how to do for ascending sorting. At position 1 it needs to be minimal element. Can we bring minimal element there using good operations? Yes. Just do “1 2” “1 3” “1 4” ... “1 M”. It basically compares element from position 1 to any other element from array. When other element has smaller value, swap is done. After comparing with all M elements, minimal value will be at position 1. By now on I’ll ignore position 1 and move to position 2. Suppose array starts from position 2. It also needs minimal value from array, except value from position 1 (which is no longer in array). Hence doing “2 3” “2 4” “2 5” ... “2 M” is enough, by similar reasons. For a position i, I need minimal value from array, except positions 1, 2, ..., i – 1. I simply do “i i+1” “i i+2” ... “i M-1” “i M”. By arriving at position i, array will be sorted ascending. The algorithm is simply:</p><p>for (int i = 1; i < M; ++i)</p><p>for (int j = i + 1; j <= M; ++j)</p><p>cout << i << “ “ << j << “\\n”;</p><p>This algorithm does exactly M * (M — 1) / 2 moves.</p><p>Can you find out how to sort array in descending order? Try to think yourself, then if you don’t get it read next. At first position of a descending array it needs to be maximal value. Similarly to ascending order, we can do “2 1” “3 1” “4 1” ... “M 1”. When I’m at a position i and I compare its value to value from position 1, doing operation “i 1” checks if A[i] > A[1]. If so, it swaps A[i] and A[1], so position 1 will contain now the maximum value so far. Similarly to logic from ascending order, when I’m at position i, I need maximum value from array except positions 1, 2, ..., i – 1, so I do “i+1 i” “i+2 i” ... “M i”. Algorithm is:</p><p>for (int i = 1; i < M; ++i)</p><p>for (int j = i + 1; j <= M; ++j)</p><p>cout << j << “ “ << i << “\\n”;</p><p>Obviously, this does as well M * (M — 1) / 2 operations worst case. All algorithm is about 10 lines of code, much better than other solution, which requires two manually sorts and also has a chance to exceed TL.</p><p>Code: <a href=\"http://pastie.org/8651809\">http://pastie.org/8651809</a></p><h1><a href=\"/contest/384/problem/C\" title=\"Codeforces Round 225 (Div. 2)\">384C - Milking cows</a></h1><p>A good strategy to approach this problem is to think how optimal ordering should look like. For this, let’s calculate for each 2 different cows i and j if cow i needs to be milked before or after cow j. As we’ll show, having this information will be enough to build optimal ordering. It is enough to consider only cases when i < j, case when i > j is exactly the opposite of case i < j. For formality, I’ll call the optimal ordering permutation and lost milk the cost of permutation.</p><p>So, for an optimal permutation P let’s take 2 numbers i < j and see in which cases i should appear before j in permutation (i is before j if P[pos1] = i, P[pos2] = j and pos1 < pos2; otherwise we’ll call i is after j). We have 4 possible cases:</p><p>1/ A[i] = 0 and A[j] = 0</p><p>If we put i before j, no additional cost will be added. Since j is in right of i and i only adds cost when it finds elements in left of i, j won’t be affected when processing i. When processing j, i will be already deleted so it won’t affect the cost either. Hence, we can put i before j and no cost will be added.</p><p>2/ A[i] = 0 and A[j] = 1</p><p>Here, i and j can appear in arbitrary order in permutation (i can be before or after j). No matter how we choose them, they won’t affect each other and cost will remain the same.</p><p>3/ A[i] = 1 and A[j] = 0</p><p>As well, here i and j can appear in arbitrary order. If we choose i first, j will be in right of it, so cost of permutation will increase by one. If we choose j first, i will be in left of it so cost of permutation will increase as well. No matter what we do, in this case cost of permutation increases by 1.</p><p>4/ A[i] = 1 and A[j] = 1</p><p>Here, i needs to be after j. This adds 0 cost. Taking i before j will add 1 cost to permutation (since j is in right of i).</p><p>Those 4 cases show us how a minimal cost permutation should look. In a permutation like this, only case 3/ contributes to final cost, so we need to count number of indices i, j such as i < j and A[i] = 1 and A[j] = 0 (*). If we show a permutation following all rules exists, task reduces to (*).</p><p>By cases 2/ and 3/ it follows that in an optimal permutation, it only matters order of elements having same value in A[]. We can put firstly all elements having value 0 in A[], then all elements having value 1 in A[]. We can order elements having value 0 by case 1/ and elements having value 1 by case 4/. More exactly, suppose i1 < i2 < ... < im and (A[i1] = A[i2] = ... = A[im] = 0) and j1 > j2 > ... > jn (A[j1] = A[j2] = ... = A[jn] = 1). Then, a permutation following all rules is {i1, i2, ..., im, j1, j2, ..., jn}. This permutation can always be built.</p><p>Hence, task reduces to (*): count number of indices i, j such as i < j and A[i] = 1 and A[j] = 0. We can achieve easily an O(N) algorithm to do this. Let’s build an array cnt[j] = number of 0s in range {j, j + 1, ..., N} from array A. We can easily implement it by going backwards from N to 1. The result is sum of cnt[i], when A[i] = 1.</p><p>Code: <a href=\"http://pastie.org/8651813\">http://pastie.org/8651813</a></p><h1><a href=\"/contest/384/problem/D\" title=\"Codeforces Round 225 (Div. 2)\">384D - Volcanoes</a></h1><p>Our first observation is that if there is a path from (1, 1) to (N, N), then the length of path is 2 * N – 2. Since all paths have length 2 * N – 2, it follows that if there is at least one path, the answer is 2 * N – 2 and if there isn’t, the answer is -1. How to prove it? Every path from (1, 1) to (N, N) has exactly N – 1 down directions and exactly N – 1 right directions. So, total length for each path is N – 1 + N – 1 = 2 * N – 2. </p><p>So we reduced our problem to determine if there is at least one path from (1, 1) to (N, N). This is the challenging part of this task, considering that N <= 10 ^ 9. How would you do it for a decently small N, let’s say N <= 10^3 . One possible approach would be, for each row, keep a set of reachable columns. We could easily solve this one by doing this: if (i, j) denotes element from ith row and jth column, then (i, j) is (is not) reachable if:</p><p>if (i, j) contains a volcano, then (i, j) is not reachable. Otherwise, if at least one of (i – 1, j) and (i, j – 1) is reachable, then (i, j) is reachable. Otherwise, (i, j) is not reachable.</p><p>What’s the main problem of this approach? It needs to keep track of 10^9 lines and in worst case, each of those lines can have 10^9 reachable elements. So, worst case we need 10^9 * 10^9 = 10^18 operations and memory.</p><p>Can we optimize it? We can note for beginning that we don’t need to keep track of 10^9 lines, only m lines are really necessarily. We need only lines containing at least one obstacle (in worst case when each line contains only one obstacle, we need m lines). How to solve it this way? Suppose line number x contains some obstacles and lines x + 1, x + 2, x + 3 do not contain any obstacle. Suppose we calculated set S = {y | cell (x, y) is reachable}. How would look S1, S2, S3 corresponding to lines x + 1, x + 2, x + 3? For S1, we can reach cell (x + 1, ymin), where ymin is minimal value from set S. Then, we can also reach {ymin + 1, ymin + 2, ..., N}, by moving right from (x + 1, ymin). So S1 = {ymin, ymin + 1, ..., N}. How do S2 and S3 look? It’s easy to see that they’ll be as well {ymin, ymin + 1, ..., N}. So we get following optimization: suppose set of lines containing at least one obstacle is {L1, L2, ..., Lk}. We need to run algorithm only for lines L1, L1 + 1, L2, L2 + 1, L3, L3 + 1, ..., Lk, Lk + 1.</p><p>It looks like we didn’t make anything with this optimization. Even if we calculate for m lines, each line can still have 10^9 reachable positions. So worst case we perform 10^14 operations. We need something better for managing information from a line. You can note that for a given line y, there are a lot of positions having consecutive values. There are a lot of positions (x, y) and (x, y + 1) both reachable. This should give us following idea: what if instead of keeping reachable positions, we keep reachable ranges? That is, for each line x we keep a set of ranges S = {(a, b) | all cells (x, k) with a <= k <= b are reachable}. </p><p>How many ranges can it be for a line? If the line contains m obstacles, there are m + 1 ranges. Suppose for line x all cells are reachable, but for line x + 1 cells (x + 1, 3) (x + 1, 5) (x + 1, N – 1) are blocked. Then, the ranges of reachable cells are [1, 2] [4, 4], [6, N – 2] and [N, N]. By now, we get worst case m lines and worst case each line having m elements, so in worst case we’d have to handle m * m = 10 ^ 10 events. This may still look too much, but happily this bound is over estimated. If a line has o obstacles, there can be at most o + 1 ranges. If lines L1, L2, ..., Lk have {o1, o2, ..., ok} obstacles, there’ll be at most o1 + o2 + ... + ok + k ranges. But o1 + o2 + ... + ok = m and also k is at most m (proved above why we’re interested in at most m lines), so in worst case we get m + m = 2 * m ranges. Yaay, finally a decent number of states for this problem :)</p><p>So, we iterate each line we’re interested in. Let’s find set of ranges for this line, thinking that all cells from line above are reachable. This is easy to do. After we get our ranges like all cells from above can be visited, let’s think how having obstacles above can influence current ranges. After adding ranges from above, current ranges can’t increase (obviously), they can only decrease, remain the same or some of them can become empty. So, let’s take each range [a, b] from current line and see how it will transform after adding ranges from previous line. </p><p>Given range [a, b], it can transform only in [a’ , b] with a’ >= a. If a’ > b, then obviously range is empty. Why second number of range keeps constant? Let a’ smallest reachable column from current line which is in range [a, b]. It’s enough to check a’ >= a, as if a’ > b, range will be empty. It’s obviously why we need to keep a’ smallest value possible >= a: we’re interested to keep range as big as possible and as less as we cut from left, as big it is. Once we’ve found a’ in range [a, b] (or a’ > b if range is empty) all cells {a’ + 1, a’ + 2, ..., b} are reachable as well by going right from a’, so if interval is not empty, then second number defining it remains b.</p><p>Next question is how to find a’ fast enough. In order a point a’ to be reachable on current range, it also needs to exist a range on previous line containing it. If the range from previous line is [pa, pb] then a’ needs to follow 3 conditions:</p><p>a’ minimal such as</p><p>pa <= a’ <= pb</p><p>a’ >= a</p><p>What if instead of finding a’ we find [pa, pb]? Then a’ is max(pa, a). In order a’ to be as small as possible, since a is constant, pa needs to be as small as possible. So we reduced it to:</p><p>pa minimal pb >= a’ >= a <=> pb >= a</p><p>Intervals from previous line are disjoint, no 2 intervals cross each other. It means that if pb is minimal, than pa is minimal too (if we increase pb, then pa will increase too, so it won’t be minimal). Hence, you need to find an interval [pa, pb] such as pb is minimal and pb >= a. Then, a’ is max(a, pa). This is easy to do if we sort all intervals from previous line increasing by second value (pb), then we binary search for value a. </p><p>Finally, after running algorithm for all lines, last range from last line has second number N (assuming ranges are sorted increasing by second value), then there exist a path, otherwise there does not exist. This algorithm should run O(m * logm) worst case, good enough to pass. </p><p>Code: <a href=\"http://pastie.org/8651817\">http://pastie.org/8651817</a></p><h1><a href=\"/contest/384/problem/E\" title=\"Codeforces Round 225 (Div. 2)\">384E - Propagating tree</a></h1><p>This is kind of task that needs to be break into smaller subproblems that you can solve independently, then put them together and get solution.</p><p>Let’s define level of a node the number of edges in the path from root to the node. Root (node 1) is at level 0, sons of root are at level 1, sons of sons of root are at level 2 and so on.</p><p>Now suppose you want to do an operation of type 1 to a node x. What nodes from subtree of x will be added +val (a positive value)? Obviously, x will be first, being located at level L. Sons of x, located at level L + 1 will be added –val. Sons of sons, located at level L + 2, will be added value +val again. So, nodes from subtree of x located at levels L, L + 2, L + 4, ... will be added a +val, and nodes located at levels L + 1, L + 3, L + 5 will be added a –val. Let’s take those values of L modulo 2. All nodes having remainder L modulo 2 will be added a +val, and nodes having reminder (L + 1) modulo 2 will be added –val. In other words, for a fixed x, at a level L, let y a node from subtree of x, at level L2. If L and L2 have same parity, +val will be added to y. Otherwise, -val will be added to y.</p><p>From here we have the idea to split nodes of tree in 2 sets – those being located at even level and those being located at odd level. What still makes the problem hard to solve? The fact that we have a tree. If nodes from a subtree would be a contiguous sequence instead of some nodes from a tree, problem would be simpler: the problem would reduce to add / subtract values to all elements of a subarray and query about a current value of an element of array. So, how can we transform tree to an array, such as for a node x, all nodes from subtree of x to be a subarray of array?</p><p>The answer is yes. We can do this by properties of DFS search. Before reading on, make sure that you know what is discovery time and finish time in a DFS search. Let’s build 3 arrays now – discover[], representing nodes in order of their discover times (a node is as before in discover as it has a small discover time), begin[] = for a node, in which time it was discovered and end[] = what’s last time of a discovered node before this node finishes. For a subtree of x, all nodes in the subtree are nodes in discover from position begin[x] to end[x].</p><p>Example: suppose you have tree 1-5; 1-6; 6-7; 6-4; 4-2; 4-3</p><p>Discover is {1, 5, 6, 7, 4, 2, 3}.</p><p>begin is {1, 6, 7, 5, 2, 3, 4}.</p><p>end is {7, 6, 7, 7, 2, 7, 4}.</p><p>What’s subtree of node 6? elements of discover from position begin[6] to end[6]. In this case, from 3 to 7, so elements {6, 7, 4, 2, 3}. You can see it’s correct and take more examples if you want :)</p><p>Now, we reduced problem to: you’re given an array A. you can perform 2 operations:</p><p>1/ increase all elements from a range [x, y] to a value val (val can be negative, to treat subtractions)</p><p>2/ what’s current value of an element from position pos.</p><p>Those who solved “Iahub and Xors” from my last round, CF 198, should probably say they saw something similar before. If you didn’t solve problem before, I encourage you to do it after you solve this one, it uses a similar idea to what will follow now. Also, if you don’t know Fenwick trees, please read them before moving on. An alternative would be for this task using segment trees with lazy update, but I see this one more complicated than needed.</p><p>I’ll use now a not so common approach when dealing with data structures. Instead of keeping in a node the result, like you usually do, I’ll keep just an auxiliary information. So what algorithm proposed does:</p><p>Let A an array, initially with all elements 0.</p><p>When you need to update range [x, y] with value val, you simply do A[x] += val and A[y + 1] -= val.</p><p>When you need to answer a query about position pos, you output A[1] + A[2] + ... + A[pos].</p><p>Implemented brute force, you get O(1) per update and O(N) per query. However, these both are operations supported by a Fenwick tree, so you can get O(logN) per operation.</p><p>It may not be very clear why this algorithm works. Let’s take a closer look: an update needs to add value val only to range [x, y]. When you query a position pos, let’s see if algorithm handles it correctly:</p><p>1/ pos < x. In this case, result must not be affected by my update. Since pos < x and I only updated 2 values with indices >= x, when doing A[1] + A[2] + ... + A[pos] it won’t matter at all I did that update – at least not for this query.</p><p>2/ x <= pos <= y. Here, for a pos, I need to add value val only once. We add it only at A[x] – in this way it will be counted once, and it will be considered for each elements from range [x, y] (since an element at position p from range [x, y] has p >= x, in A[1] + A[2] + ... + A[p] I’ll have to consider A[x]).</p><p>3/ pos > y. Here I don’t have to consider the query. But it would be considered when processing A[x]. But if I add to A[y + 1] value –val I’ll just cancel the value previously added.</p><p>Code (actually we use just one Fenwick tree instead of 2, can you think why it works? :) ) : <a href=\"http://pastie.org/8651824\">http://pastie.org/8651824</a></p><h1><a href=\"/contest/383/problem/D\" title=\"Codeforces Round 225 (Div. 1)\">383D - Antimatter</a></h1><h2>Author's solution</h2><p>The problem is: given an array, iterate all possible subarrays (all possible elements such as their indexes are consecutive). Now, for a fixed subarray we need to know in how many ways we can color its elements in black and white, such as sum of black elements is equal to sum of white elements. The result is sum of this number, for each subarray.</p><p>Let’s solve an easier problem first. This won’t immediately solve the harder version, but it will be useful later. Suppose you’ve fixed a subarray. In how many ways can you color it with black and white? Suppose subarray has N elements and sum of them is M. Also, suppose for a coloring, sum of blacks is sB and sum of whites is sW. For coloring to be valid, sB = sW. But we also know that sB + sW = M (because each element is colored by exactly one color). We get that 2 * sB = M, so sB = M / 2. The problem is now: in how many ways can we color elements in black such as sum of blacks is M / 2 (after we fix a black coloring, we color with white non colored elements; sum of white colored elements is also M / 2). This is a well known problem: Knapsack problem. Let ways[i][j] = in how many ways one can obtain sum j from first i elements. When adding (i + 1) object, after ways[i] is calculated, for a fixed sum j we can do 2 things: add (i + 1) object to sum j or skip it. Depending of what we chosen, we add value ways[i][j] to ways[i + 1][j + value[i + 1]] or to ways[i + 1][j]. The result is in ways[N][M / 2]. This works in O(N * M) time.</p><p>An immediate solution can be obtained now: take all subarrays and apply above approach. This leads to an O(N ^ 2 * M ^ 2) solution, which is too much. One can reduce complexity to O(N ^ 2* M) by noting that processing subarray [i, j] can be done with already calculated values for subarray [i, j – 1]. Hence, instead of adding N elements, it’s enough to add 1 element to already calculated values (element from position j). Sadly, O(N ^ 2 * M) is still too slow, so we need to find something better. The solution presented below will look forced if you didn’t solve some problems with this technique before. It’s hard to come with an approach without practicing this kind of tasks. But don’t worry, as much as you practice them, as easily you’ll solve those problems.</p><p>We’ll solve task by divide and conquer. Complexity of this solution is O(N * M * logN). Let f(left, right) a function that counts number of colorings for each subarray [i, j], such as subarray [i, j] is included in subarray [left, right] (left <= i <= j <= right). Answer is in f(1, N). The trick is to define a value med = (left + right) / 2 (very frequent trick in divide and conquer problems, called usually a median). We can next classify [i, j] subarrays in 3 types:</p><p>1/ i <= med j <= med</p><p>2/ i > med j > med</p><p>3/ i <= med j > med</p><p>We can solve 1/ and 2/ by calling f(left, med) and f(med + 1, right). The remained problem is when i <= med and j > med. If we solve 3/ in O((right – left) * M) time, this will be enough to overall achieve O(N * M * logN) (for this moment trust me, you’ll see later why it’s so :) ).</p><p>Let’s denote by i1 last i1 elements from subarray [left, med]. Also, let’s note by i2 first i2 elements from subarray [med + 1, right]. For example, let left = 1 and right = 5, with array {1, 2, 3, 4, 5}. med is 3 and for i1 = 2 and i2 = 1, “left” subarray is {2, 3} and “right” subarray is {4}. By iterating i1 from 1 to med – left + 1 and i2 from 1 to right – med and then unite subarrays i1 and i2, we obtain all subarrays described in 3/ . Let’s denote by j1 sum of a possible black coloring of i1. Similarly, j2 is sum of a possible black coloring of i2.</p><p>Suppose we fixed i1, i2, j1 and j2. When it’s the coloring valid? Let S sum of united subarrays i1 and i2 (S = value[med – i1 + 1] + value[med – i1 + 2] + ... + value[med] + value[med + 1] + ... + value[med + i2 – 1] + value[med + i2]). Now it’s time to use what I explained at the beginning of solution. The coloring is good only when j1 + j2 = S / 2. We can rewrite the relation as 2 * (j1 + j2) = sum_of_elements_from_i1 + sum_of_elements_from_i2. We can rewrite it even more:</p><p>2 * j1 + 2 * j2 — sum_of_elements_from_i1 — sum_of_elements_from_i2 = 0</p><p>2 * j1 – sum_of_elements_from_i1 = sum_of_elements_from_i2 – 2 * j2 = combination_value</p><p>This relation is the key of solving problem. You can see now that relation is independent in “left” and “right” side. We calculate left[i1][j1] and right[i2][j2] = in how many ways can I obtain sum of blacks j1 (j2) from first i1 (i2) from left (right) side. Let’s calculate also count[value] = in how many ways can I obtain combination_value equal to value in the right side. For some fixed (i2, j2) I add to count[sum_of_elements_from_i2 – 2 * j2] value right[i2][j2]. In this way count[] is calculated correctly and completely. Now, let’s fix a sum (i1, j1) in the left side. We’re interested how many good colorings are such as there exist a coloring of j1 in i1 elements (the endpoint of “left” is fixed to be i1 and I need to calculate endpoints i2 for right, then to make colorings of i2). A coloring is good if combination_value of (i1, j1) and (i2, j2) is equal. Hence, I need to know in how many ways I can color i1 elements to obtain sum j1 and also I need to know in how many ways I can color elements from right to obtain same combination_value as it’s in the left. It’s not hard to see that answer for a fixed (i1, j1) is left[i1][j1] * count[2 * j1 – sum_of_elements_from_i1]. This takes O((right – left) * M) time.</p><p>The only thing remained in the problem is to see why complexity is O(N * M * logN). We can assume N is a power of 2 (it not, let’s round N to smallest power of 2 bigger than N; complexity for N is at least as good as complexity for this number). Draw a binary complete tree with N nodes. Each node corresponds to an appeal of f(). For a level, exactly O(N * M) operations are performed. To see why:</p><p>For level 1, there’ll be 1 node performing N * M operations.</p><p>For level 2, there’ll be 2 nodes performing (N / 2) * M operations. Summing up we get O(N * M).</p><p>For level 3, there’ll be 4 nodes performing (N / 4) * M operations. Summing up we get O(N *M) as well.</p><p>and so on.</p><p>So for each level we perform O(N * M) operations. A binary complete tree has maximum O(logN) levels, so overall complexity is O(N * M * logN).</p><p>Code: <a href=\"http://pastie.org/8651826\">http://pastie.org/8651826</a></p><h2>Solution fount by contestants</h2><p>This was totally unexpected to us :) Good job finding it, you guys are really smart. </p><p>We observe that x units of antimatter is the same thing as -x units of matter. Then we can consider that an element produces either x or -x units of matter. A valid substring is one that can have the sum of the elements 0. The problem is reduced to finding how many different substrings can we have with sum 0 (a substring is different than another one if it has different indices, or if at least one element produces matter in one and antimatter in the other).</p><p>This problem can be solved with dynamic programming. We will hold D[i][j] = the number of substrings that end in element i, and have sum j. It's easy to see that D[i + 1][j] = D[i][j — x] + D[i][j + x], where x is the value of the current element (we can put either -x or x). After we finish computing all the values for current i, we add to the solution D[i][0] (how many valid substrings do we have). After that, we add 1 to D[i][0], meaning that there is an empty substring starting at position i (however, we don't need to add it to the answer).</p><p>For a code, check passing submissions during contest. </p><h2><a href=\"/contest/383/problem/E\" title=\"Codeforces Round 225 (Div. 1)\">383E - Vowels</a></h2><h2>Author's solution</h2><p>Let's iterate over all possible vowel sets. For a given set {x1, x2, ..., xk} we're interested in number of correct words from dictionary. After a precalculation, we can do it in O(k).</p><p>Suppose our current vowel set is {x1, x2, ..., xk}. How many words are covered by the current vowels? By definition, we say a word is covered by a set of vowels if at least one of 3 letters of word is in vowel set. We can calculate this number using principle of inclusion and exclusion. We’ll denote by |v1, v2, v3, ...| = number of words containing ALL of vowels v1, v2, v3, ... . Using principle of inclusion and exclusion we get:</p><p>number_of_words_covered = |x1| + |x2| + .. + |xk| — |x1, x2| — |x1, x3| — .... + |x1, x2, x3| + |x1, x2, x4| + .... + |xk-2, xk-1, xk|. This formula is simply a reformulation of principle of inclusion and exclusion. You can easily observe that |v1, v2, ..., vk| makes sense only when k is at most 3, as no word from input can contain 4 or more letters (and hence can’t contain 4 or more vowels). </p><p>Example:</p><p>Suppose words are abc, abd and bcd. </p><p>|a| = 2 (first 2 words both contain character a).</p><p>|a, b| = 2 (as well, first 2 words contain characters a and b).</p><p>|b| = 3 (all 3 words contain character b).</p><p>|a, b, d| = 1 (only second word contains all 3 characters).</p><p>Also, note how principle of inclusion and exclusion works. number of words covered for vowels {a, b} is |a| + |b| — |a, b| = 2 + 3 – 2. Indeed, answer is 3.</p><p>We divide our problem in 3 subproblems. First one, for a vowel set, compute sum of |a|, where a is a letter from subset. Second, compute sum of |a, b|, where both a and b are letters from set. Third, compute sum of |a, b, c|, where a, b, c are letters from set. As stated, the answer is number_from_1st_step + number_from_3rd_step – number_from_2nd_step. If you followed me, you’ll see that we want to compute results for each subproblem in O(queryLetters).</p><p>First subproblem can be solved trivially in O(queryLetters). Let array single[], with following meaning: single[c] is how many words contain character c. It can be trivially precomputed in O(24 * N). Note that if a word contains twice/third times a character c, it needs to be counted only one (e.g. word aba will add only 1 to single[a]). For compute result of this subproblem for a given set of vowels, I’ll take all letters from set. If letter belongs to set, I add to result single[letter]. This step can be also be solved in O(1), but there’s no need, since other subproblems allow only an O(queryLetters) solution. </p><p>For second and third subproblems it’s a little more difficult. I’ll present here how to solve second subproblem and some hints for third one (if you understand second, with hints you should be able to solve third one by your own).</p><p>Similarly to first step, I’ll define a matrix double[c1][c2] = how many words contain both characters c1 and c2. A trivially solution would be, for a given vowel set, take all combinations of letters c1 and c2 that belong to set and add to result value double[c1][c2]. However, this solves each query in O(queryLetters^2), which is too slow.</p><p>Note, if we’d have 12 letters, instead of 24, this approach would be fast enough. From here it comes a pretty classical idea in exponential optimization: meet in the middle attack. We split those 24 letters in 2 groups: first 12 letters and last 12 letters. The answer for a subset is sum of double[c1][c2] (when c1 and c2 belong to current vowel set) when</p><p>1/ c1 and c2 belong to first 12 letters</p><p>2/ c1 and c2 belong to last 12 letters</p><p>3/ c1 belongs to first 12 letters and c2 belongs to last 12 letters</p><p>1/ and 2/ can be immediately precalculated as stated above, in O(2 ^ 12 * 12 ^ 2). We’ll remember results for each half using bitmasks arrays. Let Half1[mask] = sum over double[c1][c2], when c1 and c2 are in first 12 letters and correspond to 1 bits of mask. Half2[mask] is defined similarly, but for last 12 letters (e.g. subset {a, c, d} corresponds to bitmask 2^0 + 2^2 + 2^3 = 13 in first half and subset {m, n, p} corresponds to bitmask 2^0 + 2^1 + 2^3 = 11 for second half). Now, for a given subset, one can answer first 2 parts in O(queryCount) worst case (read input for a query and convert it to bitmasks). </p><p>How to answer 3? With another precalculation, of course. We know c1 letter needs to be in first 12 letters and c2 needs to be in last 12 letters. The precalculation we do here is: mixed_half[mask][i] = sum over |c1, c2|, when c1 belongs to first half and is a 1 bit of mask and c2 is i-th character of second half. Hence, for a query, we can fix character from second half (c2, by iteration of query letters from second half) and know sums of |c1, c2| between it and all available characters from first half after we do this precalculation. Also, precalculation is done trivially in O(2 ^ 12 * 12^2): fix mask, fix i and then iterate over 1 bits from mask and add double[c1][c2]. </p><p>Third subproblem is left, but it can be done similarly to second one. Instead of double[c1][c2], we’ll have triple[c1][c2][c3] = how many words contain all 3 characters c1, c2 and c3? We also do meet in the middle here, divide those 24 letters into 2 sets of 12 letters. We have 4 cases:</p><p>1/ c1, c2, c3 belong to first half</p><p>2/ c1, c2, c3 belong to second half</p><p>3/ c1, c2 belong to first half and c3 to second half</p><p>4/ c1 belongs to first half and c2, c3 to second half</p><p>1/ and 2/ are done brute force, like in second subproblem (the only difference is we choose 3 characters instead of 2, having complexity O(2 ^ 12 * 12 ^ 3)). For 3/ and 4/ we also precompute 2 matrixes: </p><p>mixed_two_one[mask][i] = c1 and c2 belong to mask from first half and c3 is i-th character from second half </p><p>and </p><p>mixed_one_two[mask][i] = c1 is i-th character from first half and c2, c3 belong to mask from second half. </p><p>Those can also be calculated in O(2 ^ 12 * 12^3).</p><p>So precalculation part is O(2 ^ 12 * 12 ^ 3) = 7077888 operations.</p><p>For calculate answering queries complexity, take all numbers from 0 to 2^24 — 1 and sum their bit count. This is a well known problem, the sum is 0 * C(24, 0) + 1 * C(24, 1) + ... + 24 * C(24, 24) = 201326592. In total we get 208404480 operations. C++ source makes them in 2 seconds. </p><p>Code: <a href=\"http://pastie.org/8651829\">http://pastie.org/8651829</a></p><h2>Solution fount by contestants</h2><p>Like in D1 D task, official solution was over complicated. This solution is more simple to understand, code and it's more elegant. If someone wants to complicate his life, (s)he can code also official solution :)</p><p>Let's start by assigning a bitmask to each word in following way: ith bit is 1 if and only if letter ('a' + i) appears in the current word. For example, for word acd, its bitmask is 2^0 + 2^2 + 2 ^ 3 = 13 and for word aab its bitmask is 2^0 + 2^1 = 3. After reading the words from dictionary, we store a matrix cnt[mask] = how many words from dictionary correspond to mask?</p><p>We iterate bitmasks from 0 to 2^24 — 1, this time corresponding to each possible question of Iahubina. Let's focus on a bitmask X. We need to get sum of cnt[mask], when mask and X share at least one common bit having value 1 (formally (X AND mask) > 0). In order to do this, we need a reduction which may be not so obvious. </p><p>What if instead of counting all words containing at least one of vowels {w1, w2, ..., wk} we count all words which don't contain ANY of vowels {w1, w2, ..., wk}? Suppose this number is ret. Then, all words containing at least one of vowels is N — ret. From all words, we erase those words which do not contain any vowels from set {w1, w2, ..., wk} (and which obviously are wrong words). Obviously, it's left only words containing at least one vowel, so good words. Now, for a word not to contain any of vowels {w1, w2, ..., wk} it needs to contains ONLY vowels from set {"a", "b", "c", ..., "x"} \\ {w1, w2, ..., wk} (set of allowed letters from which we erased vowels w1, w2, ..., wk}. </p><p>And this is reduction we needed. For a bitmask X we need to calculate sum of cnt[mask], where mask is a subset of X (we can set some bits from X from 1 to 0 in order to obtain mask). For a mask, let's keep this sum in res[mask]. We can calculate res array using divide and conquer.</p><p>Let's make a function solve(left, right), which completes array res in the way described above, if we consider only elements cnt[k] with left <= k < right (for simplicity, I'll consider elements which do not lie in this range to be equal to 0). Now we need to solve for a range [left, right]. Let's have in res1[] = solve(left, med) and in res2[] = solve(med, right), where med = (left + right) / 2. We need to put together res1[] and res2[] in order to obtain res[].</p><p>for (int i = left; i < med; ++i) res[i] = res1[i];</p><p>Numbers in [left, med] have most significant bit equal to 0. We can only keep it 0 and add what we calculated before. We can't add any element from res2[], because those elements have most significant bit equal to 1 and we're not allowed to change bit 0 into bit 1.</p><p>for (int i = med; i < right; ++i) res[i] = res1[i — med] + res2[i];</p><p>Here, most significant bit is 1. Adding res1[] corresponds to changing bit from 1 to 0, adding res2[] corresponds to leaving bit 1.</p><p>Of course, we need to threat the base case here, too. When left + 1 = right, res[left] = cnt[left]. We can keep only one array res[] instead of 3, I explained it this way only for simplicity. Also, there is no need for keeping separate arrays for res[] and cnt[], one can solve all task with only one array. In order to get res[], we simply call solve(0, 2^24).</p><p>Complexity of solution is O(2 ^ 24 * 24). I leave the proof homework, it's almost identical to complexity proof of D1 D "Author solution" (that with building a binary tree).</p><p>For a reference solution, check <a class=\"rated-user user-red\" href=\"/profile/Endagorion\" title=\"Grandmaster Endagorion\">Endagorion</a>'s AC source during contest. </p></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/384\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 225 (Div. 2)</a> </span>\r\n </div>\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/383\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 225 (Div. 1)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-12457-10531\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"12457\",\n blogEntryId: \"10476\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n <div style=\"font-size: 1.1rem;line-height: 11px;\">\r\n <img style=\"vertical-align: middle;\" src=\"//codeforces.org/s/81027/images/blog/tags.png\" title=\"Tags\" alt=\"Tags\"/>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=codeforces\" class=\"tag notice\" style=\"text-decoration: none;\">codeforces</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=225\" class=\"tag notice\" style=\"text-decoration: none;\">225</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=editorial\" class=\"tag notice\" style=\"text-decoration: none;\">editorial</a>\r\n </span>\r\n </div>\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-10531\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+418</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-10531\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/fchirica\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/fchirica\">\n fchirica\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Jan/20/2014 22:18\">10 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/10476#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/10476#comments\">\n 52\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"10547\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (45)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158582\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PAP\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/78534/avatar/d5bcc04085999f83.jpg'/> </a>\n <div><a href=\"/profile/PAP\" title=\"Candidate Master PAP\" class=\"rated-user user-violet\">PAP</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 22:40\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158582\" href=\"?#comment-158582\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158582\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"32\"\r\n data-commentUserId=\"78534\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+32</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158582\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>perfect editorial! thanks a lot!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158582 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158582 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158582\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158591\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/eduardische\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2320/avatar/3ac70493aa90ad2e.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/eduardische\" title=\"International Master eduardische\" class=\"rated-user user-orange\">eduardische</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 22:48\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158591\" href=\"?#comment-158591\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"158591\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"158591\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"10\"\r\n data-commentUserId=\"2320\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+10</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158591\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Just would like to report a typo in 383D contestants' solution: the formula computes D[i+1][j] and not D[i][j]. Thanks for the quick editorial!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158591 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158591 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158591\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158596\" commentParentId=\"158591\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/fchirica\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/57267/avatar/4e655c69b8ad66c2.jpg'/> </a>\n <div><a href=\"/profile/fchirica\" title=\"Candidate Master fchirica\" class=\"rated-user user-violet\">fchirica</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 22:52\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158596\" href=\"?#comment-158596\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-158591\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158596\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"15\"\r\n data-commentUserId=\"57267\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+15</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158596\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks. Fixed. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158596 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158596 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158596\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158598\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Mikester\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/109566/avatar/401b6d72d8f2e768.jpg'/> </a>\n <div><a href=\"/profile/Mikester\" title=\"Master Mikester\" class=\"rated-user user-orange\">Mikester</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 22:54\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158598\" href=\"?#comment-158598\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158598\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"13\"\r\n data-commentUserId=\"109566\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+13</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158598\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>elfus has some of the best rounds on Codeforces, and definitely the best editorials. Congratulations to you and Rares for the round !</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158598 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158598 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158598\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158599\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/iPs\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/144469/avatar/10358ae72910ceac.jpg'/> </a>\n <div><a href=\"/profile/iPs\" title=\"Expert iPs\" class=\"rated-user user-blue\">iPs</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 22:54\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158599\" href=\"?#comment-158599\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158599\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"33\"\r\n data-commentUserId=\"144469\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+33</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158599\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>best editorial I have ever seen in codeforces</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158599 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158599 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158599\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158600\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/bli0042\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/88584/avatar/51c3a9b55a3537fa.jpg'/> </a>\n <div><a href=\"/profile/bli0042\" title=\"Candidate Master bli0042\" class=\"rated-user user-violet\">bli0042</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 22:54\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158600\" href=\"?#comment-158600\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"158600\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"158600\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"88584\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158600\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For Div 2C, if A[i] = A[j] = 0 and we put i before j, won't j lose milk? Or am I misinterpreting the solution?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158600 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158600 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158600\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158601\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/aabs08\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/aabs08\" title=\"Expert aabs08\" class=\"rated-user user-blue\">aabs08</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 22:55\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158601\" href=\"?#comment-158601\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"158601\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"158601\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"9\"\r\n data-commentUserId=\"86699\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+9</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158601\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>One of the best editorials i came across in codeforces :D otherwise the editorial here are really very short and objective.</p><p>Every one here should write editorials like you :) !!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158601 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158601 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158601\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158607\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Xellos\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/69675/avatar/8526bcfc8e687b43.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/Xellos\" title=\"International Grandmaster Xellos\" class=\"rated-user user-red\">Xellos</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 23:03\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158607\" href=\"?#comment-158607\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"158607\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"158607\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"17\"\r\n data-commentUserId=\"69675\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+17</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158607\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Finally a tutorial worth upvoting!</p><p>I didn't really need to think about D. As soon as I saw the constraint on <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/986936bec272878d92f9c6fb0f0ce3c5b118cc0e.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />, I decided to try a DP on (position,sum) — it was a massive hint for me. Well, sometimes it just happens that there's a simple solution, which the author doesn't realize :D. Maybe this could be eliminated by some extensive "problem testing" by random capable people?</p><p>I guess I was also lucky in not trying to solve B. I solved in the order: A (because it's easy), C (because I like it), D (because it's easy) :D</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158607 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158607 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158607\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158610\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Mostafa_36a2\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/137637/avatar/28a01293a2b409.jpg'/> </a>\n <div><a href=\"/profile/Mostafa_36a2\" title=\"Specialist Mostafa_36a2\" class=\"rated-user user-cyan\">Mostafa_36a2</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 23:09\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158610\" href=\"?#comment-158610\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158610\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"-9\"\r\n data-commentUserId=\"137637\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-9</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158610\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I've found a very short solution for Div2 C , by zxz5759209</p> <pre><code>scanf("%d",&n);\n LL cnt=0,sum=0;\n for(int i=1;i<=n;i++)\n {\n scanf("%d",&x);\n cnt+=(LL)x;\n if(!x)sum+=cnt;\n }\n printf("%I64d\\n",sum);\n</code></pre></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158610 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158610 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158610\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158641\" commentParentId=\"158610\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Robert.One\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Robert.One\" title=\"Pupil Robert.One\" class=\"rated-user user-green\">Robert.One</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 01:27\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158641\" href=\"?#comment-158641\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-158610\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158641\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"150202\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158641\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I also had this solution and i got accepted but it took 1 hour to find it during the contest</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158641 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158641 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158641\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158612\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Darek_\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Darek_\" title=\"Specialist Darek_\" class=\"rated-user user-cyan\">Darek_</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 23:12\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158612\" href=\"?#comment-158612\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158612\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"152123\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158612\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks for an informative editorial.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158612 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158612 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158612\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158618\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Mostafa_36a2\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/137637/avatar/28a01293a2b409.jpg'/> </a>\n <div><a href=\"/profile/Mostafa_36a2\" title=\"Specialist Mostafa_36a2\" class=\"rated-user user-cyan\">Mostafa_36a2</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 23:25\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158618\" href=\"?#comment-158618\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"158618\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"158618\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"137637\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158618\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Unbelivable solution for Div2,B by Sick_Coder</p> <pre><code>cin >> n >> m >> k;\n cout << m * (m - 1) / 2 << "\\n";\n\n for (1, m, i)\n \tfor (i + 1, m, j)\n \t\tif (!k)\n \t\t\tcout << i << " " << j << "\\n";\n \t\telse\t\n \t\t\tcout << j << " " << i << "\\n";\n</code></pre></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158618 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158618 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158618\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158631\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mugurelionut\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/63702/avatar/45e4d5390c215090.jpg'/> </a>\n <div><a href=\"/profile/mugurelionut\" title=\"International Master mugurelionut\" class=\"rated-user user-orange\">mugurelionut</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 23:57\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158631\" href=\"?#comment-158631\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158631\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"63702\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158631\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>A very good editorial, indeed! (but please don't forget about Div1E) And the problems were really nice. But I think problem B was tougher than it should have been for its amount of points. I've read some comments saying that problem B had too weak pretests (because so many solutions failed the final system tests). I would have to say that my experience with problem B was the exact opposite. I coded two wrong solutions (which failed some pretest or another) before eventually finding and implementing the right solution. So I'd say that problem B had good pretests :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158631 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158631 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158631\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158635\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/MohammadFatafta\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/148405/avatar/4276577919b9713d.jpg'/> </a>\n <div><a href=\"/profile/MohammadFatafta\" title=\"Specialist MohammadFatafta\" class=\"rated-user user-cyan\">MohammadFatafta</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 00:11\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158635\" href=\"?#comment-158635\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158635\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"148405\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158635\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>now this is a real editorial!! thanks guys :D</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158635 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158635 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158635\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158636\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/matrix\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/matrix\" title=\"Master matrix\" class=\"rated-user user-orange\">matrix</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 00:15\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158636\" href=\"?#comment-158636\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"158636\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"158636\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"16572\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158636\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Hi,</p><p>Great and fast editorial with complete details. </p><p>Thanks very much.</p><p>Edit: I think there is a small typo: "It’s not hard to see that answer for a fixed (i1, j1) is left[i1][j1] * value[2 * j1 – sum_of_elements_from_i1]." I guess you meant count[2 * j1 – sum_of_elements_from_i1].</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158636 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158636 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158636\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158637\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Kyuubi\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/83590/avatar/b87432a652bb276.jpg'/> </a>\n <div><a href=\"/profile/Kyuubi\" title=\"Expert Kyuubi\" class=\"rated-user user-blue\">Kyuubi</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 00:18\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158637\" href=\"?#comment-158637\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158637\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"2\"\r\n data-commentUserId=\"83590\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+2</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158637\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Best Editorials I have seen on codeforces yet! :D</p><p>For Propagating tree, how do we keep track of alternating levels in the arrays we created using DFS ? </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158637 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158637 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158637\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158640\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/k_____k\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/60285/avatar/422359e1ae9d666c.jpg'/> </a>\n <div><a href=\"/profile/k_____k\" title=\"Expert k_____k\" class=\"rated-user user-blue\">k_____k</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 01:07\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158640\" href=\"?#comment-158640\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158640\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"2\"\r\n data-commentUserId=\"60285\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+2</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158640\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Best Editorials Ever ! #thanks to the authors, for posting alternative solutions of contestants also. Great start in 2014. #Looking Forward.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158640 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158640 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158640\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158658\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/sillycross\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/41652/avatar/58966d0c793c6394.jpg'/> </a>\n <div><a href=\"/profile/sillycross\" title=\"Grandmaster sillycross\" class=\"rated-user user-red\">sillycross</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 07:49\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158658\" href=\"?#comment-158658\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158658\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"9\"\r\n data-commentUserId=\"41652\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+9</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158658\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Div1 E can be solved in O(2^24*24) or O(2^24+2^12*n)..</p><p>O(2^24*24): dp[i][s] means the sum of all contributions of subset s where all digits are same as s except the last i digits.. </p><p>O(2^24+2^12*n): the length of word is only 3. We divide the 24 letters in half, calculate the answer for all first 12 letters and all last 12 letters and merge them with brute-force. This can be solved in O(2^24). Then we subtract the words that are counted twice: these words are words that have 2 letters in first half and 1 in second half, or 2 in second half and 1 in first half. Let's consider the first case: for each subset of first 12 letters we check each word whether it has exactly 2 letters in this half, if so, we can say all masks in another half that contains the third letter need to be subtracted by 1. This can be solved in 2^12*(2^12+n). Same algorithm can be used to solve the second case. Although this algorithm runs slower than O(2^24*24) bcuz of its larger constant... </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158658 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158658 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158658\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158663\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/VeniVidiVici\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/VeniVidiVici\" title=\"Candidate Master VeniVidiVici\" class=\"rated-user user-violet\">VeniVidiVici</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 09:39\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158663\" href=\"?#comment-158663\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158663\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"149163\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158663\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Very nice editorial! Disappointed in Div 2B though, really expected the "real" problem rather than just insertion sort but that's what you get for not reading carefully ;)</p><p>However, does anyone have an accepted solution that is "real" (e.g. finds the minimum number of operations necessary and prints such a solution)? I was close but my computer died during contest and I haven't tried so much since (of course you can do O((mn)^2) easily but this is way too slow, there should be a O(n*m^2) solution but again my computer was unable to operate). My approach was to make 2-D boolean array to check if a swap is necessary, but I'm not sure if order of operations will end up being a big problem.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158663 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158663 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158663\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158685\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/LegendaryGrandmaster\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/142091/avatar/a3a5a4b5c26ac419.jpg'/> </a>\n <div><a href=\"/profile/LegendaryGrandmaster\" title=\"Specialist LegendaryGrandmaster\" class=\"rated-user user-cyan\">LegendaryGrandmaster</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 14:34\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158685\" href=\"?#comment-158685\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158685\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"142091\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158685\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>One of the best codeforces editorials ever! Thanks!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158685 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158685 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158685\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158687\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/BENYAM1N\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/84938/avatar/d2ae2657d8898e38.jpg'/> </a>\n <div><a href=\"/profile/BENYAM1N\" title=\"Master BENYAM1N\" class=\"rated-user user-orange\">BENYAM1N</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 15:24\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158687\" href=\"?#comment-158687\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"158687\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"158687\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"84938\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158687\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks a lot. very good contest and good editorial too!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158687 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158687 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158687\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158689\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/JuanMata\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/82548/avatar/a7d69af7b441c6d7.jpg'/> </a>\n <div><a href=\"/profile/JuanMata\" title=\"Expert JuanMata\" class=\"rated-user user-blue\">JuanMata</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 15:47\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158689\" href=\"?#comment-158689\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158689\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"82548\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158689\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>this is one of the best editorials on CF ever!!!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158689 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158689 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158689\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158700\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Vicfred\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/76941/avatar/d067b7433ec39337.jpg'/> </a>\n <div><a href=\"/profile/Vicfred\" title=\"Pupil Vicfred\" class=\"rated-user user-green\">Vicfred</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 16:25\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158700\" href=\"?#comment-158700\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158700\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"11\"\r\n data-commentUserId=\"76941\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+11</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158700\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>The best editorial I've read in a while here, thanks.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158700 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158700 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158700\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158727\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/beecoder\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/beecoder\" title=\"Pupil beecoder\" class=\"rated-user user-green\">beecoder</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 21:13\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158727\" href=\"?#comment-158727\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158727\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"89551\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158727\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Hi, The way I print answers for 'Coder Problem' is as follows. This takes 124 ms. is there a way to print the answers faster ? </p> <pre><code> \tfor (int i = 0 ; i < number ; i ++ ) { \n \t\tfor (int k = 0 ; k < number ; k ++ ) { \n \t\t\tif (flag) {\n \t\t\t\tif ( k % 2 == 1) out.print('.');\n \t\t\t\tif( k% 2 == 0 ) out.print('C');\n \t\t\t} else {\n \t\t\tif ( k % 2 == 1) out.print('C');\n \t\t\tif( k% 2 == 0 ) out.print('.');\t\n \t\t\t}\n \t\t}\n \t\tif (flag) flag = false;\n \t\telse flag = true;\n \t\tout.print("\\n");\n \t}\n \n</code></pre></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158727 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158727 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158727\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158742\" commentParentId=\"158727\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Mostafa_36a2\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/137637/avatar/28a01293a2b409.jpg'/> </a>\n <div><a href=\"/profile/Mostafa_36a2\" title=\"Specialist Mostafa_36a2\" class=\"rated-user user-cyan\">Mostafa_36a2</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/22/2014 14:00\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158742\" href=\"?#comment-158742\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-158727\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158742\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"137637\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158742\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>As the line contains k characters , and every odd lines are identical , also the even ones,</p><p>you can build 2 strings [C.C.C.C] and [.C.C.C.] and print them alternately </p><p>[In my opinion Java is slow language any way ]</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158742 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158742 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158742\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158752\" commentParentId=\"158727\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/t_thirupathi\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/146179/avatar/98c28348196ce4ca.jpg'/> </a>\n <div><a href=\"/profile/t_thirupathi\" title=\"Specialist t_thirupathi\" class=\"rated-user user-cyan\">t_thirupathi</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/22/2014 18:19\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158752\" href=\"?#comment-158752\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-158727\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158752\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"146179\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158752\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Modulo operations are time consuming.</p><p>To check if a number <code>n</code> is odd, you could use <code>if (n & 1)</code></p> <pre><code>for (int i = 0; i < n; i++) {\n for (int j = 0; j < n; j++)\n if ((i + j) & 1)\n out.print('.');\n else \n out.print('C');\n out.print('\\n');\n}\n</code></pre></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158752 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158752 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158752\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158745\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/JuanMata\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/82548/avatar/a7d69af7b441c6d7.jpg'/> </a>\n <div><a href=\"/profile/JuanMata\" title=\"Expert JuanMata\" class=\"rated-user user-blue\">JuanMata</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/22/2014 14:49\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158745\" href=\"?#comment-158745\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"158745\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"158745\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"82548\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158745\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>i think there is a small bug in the <a href=\"http://pastie.org/8651824\">pastie link</a> u posted for the solution of Div1 C problem.</p><p>i submitted almost exact copy of it (<a href=\"/contest/383/submission/5769615\" title=\"Submission 5769615 by JuanMata\">5769615</a>), but got WA#6. then i found the bug, corrected it and resubmitted (<a href=\"/contest/383/submission/5769890\" title=\"Submission 5769890 by JuanMata\">5769890</a>) and got AC.</p><p>referring to my two submissions, corrections in line <strong>68</strong> (last statement of <strong>dfs</strong>) and line <strong>109</strong> (the second call to <strong>update</strong>).</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158745 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158745 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158745\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"615836\" commentParentId=\"158745\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/adityakr007\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/adityakr007\" title=\"Expert adityakr007\" class=\"rated-user user-blue\">adityakr007</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/05/2020 18:54\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-615836\" href=\"?#comment-615836\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-158745\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"615836\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"866209\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-615836\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can you explain what exactly have you done in your submission (<a href=\"/contest/383/submission/5769890\" title=\"Submission 5769890 by JuanMata\">5769890</a>) for this problem?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-615836 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-615836 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-615836\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"629531\" commentParentId=\"615836\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/JuanMata\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/82548/avatar/a7d69af7b441c6d7.jpg'/> </a>\n <div><a href=\"/profile/JuanMata\" title=\"Expert JuanMata\" class=\"rated-user user-blue\">JuanMata</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/25/2020 18:14\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-629531\" href=\"?#comment-629531\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-615836\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"629531\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"82548\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-629531\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>sorry bro i've forgotten ... that was over 6yrs ago now!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-629531 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-629531 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-629531\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158751\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/TempuX\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/30820/avatar/c50adc243ea4e2fa.jpg'/> </a>\n <div><a href=\"/profile/TempuX\" title=\"Specialist TempuX\" class=\"rated-user user-cyan\">TempuX</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/22/2014 17:07\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158751\" href=\"?#comment-158751\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158751\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"30820\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158751\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Hi, I tried to implement the Volcano problem in the way explained in the editorial but I'm getting TLE. Here is my code <a href=\"//codeforces.com/contest/384/submission/5770818\">submission</a> What am I doing wrong ? Thanks anyway.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158751 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158751 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158751\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158811\" commentParentId=\"158751\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/TempuX\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/30820/avatar/c50adc243ea4e2fa.jpg'/> </a>\n <div><a href=\"/profile/TempuX\" title=\"Specialist TempuX\" class=\"rated-user user-cyan\">TempuX</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/23/2014 17:29\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158811\" href=\"?#comment-158811\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-158751\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158811\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"30820\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158811\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Turns out my binary search is causing the problem and I don't see what is wrong with it... I would appreciate any ideas.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158811 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158811 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158811\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159025\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/bboy_drain\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/76710/avatar/e0feb3aa135911d4.jpg'/> </a>\n <div><a href=\"/profile/bboy_drain\" title=\"Expert bboy_drain\" class=\"rated-user user-blue\">bboy_drain</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/25/2014 01:34\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159025\" href=\"?#comment-159025\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159025\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"76710\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159025\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Wow! This really helped me a lot! Very detailed explanations!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159025 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159025 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159025\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159092\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/AlexandruValeanu\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/131651/avatar/1c7d989c45052941.jpg'/> </a>\n <div><a href=\"/profile/AlexandruValeanu\" title=\"Candidate Master AlexandruValeanu\" class=\"rated-user user-violet\">AlexandruValeanu</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/25/2014 21:27\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159092\" href=\"?#comment-159092\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159092\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"131651\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159092\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>It was by far your best round on Codeforces, <a class=\"rated-user user-blue\" href=\"/profile/fchirica\" title=\"Expert fchirica\">fchirica</a>. The problems were great, very different one from the other and some of them didn't require any algorithmic skills at all. Good job!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159092 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159092 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159092\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159261\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lawsonh\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/lawsonh\" title=\"Expert lawsonh\" class=\"rated-user user-blue\">lawsonh</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/28/2014 06:33\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159261\" href=\"?#comment-159261\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"159261\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"159261\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"55047\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159261\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>for div1 383C should end[5] = 7? edit: nvm drew the tree wrong</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159261 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159261 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159261\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159474\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/tiagonapoli\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/150060/avatar/6615fcab66b23361.jpg'/> </a>\n <div><a href=\"/profile/tiagonapoli\" title=\"Candidate Master tiagonapoli\" class=\"rated-user user-violet\">tiagonapoli</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/30/2014 22:28\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159474\" href=\"?#comment-159474\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159474\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"150060\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159474\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Great Editorial! Thanks so much, i've learned a lot!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159474 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159474 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159474\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159707\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lchf\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/60496/avatar/e9939e755252ec16.jpg'/> </a>\n <div><a href=\"/profile/lchf\" title=\"Candidate Master lchf\" class=\"rated-user user-violet\">lchf</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/02/2014 17:28\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159707\" href=\"?#comment-159707\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159707\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"60496\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159707\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Amazing solution by Endagorion.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159707 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159707 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159707\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"177400\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/sourabh912\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/57335/avatar/bf83b9340e3cbb17.jpg'/> </a>\n <div><a href=\"/profile/sourabh912\" title=\"Specialist sourabh912\" class=\"rated-user user-cyan\">sourabh912</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/12/2014 20:39\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-177400\" href=\"?#comment-177400\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"177400\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"57335\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-177400\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In Div 1C problem, I could not understand how it can be solved using single fenwick tree from the solution link in the editorial. Can anyone please help.</p><p>Thanks</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-177400 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-177400 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-177400\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"291157\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/l_Love_KFC\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/258117/avatar/bbaec3ce1613f5bd.jpg'/> </a>\n <div><a href=\"/profile/l_Love_KFC\" title=\"Expert l_Love_KFC\" class=\"rated-user user-blue\">l_Love_KFC</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Apr/29/2016 08:23\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-291157\" href=\"?#comment-291157\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"291157\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"258117\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-291157\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In Div.1 A I didn't catch the point that in 1st, quote : "If we put i before j, no additional cost will be added. Since j is in right of i and i only adds cost when it finds elements in left of i, j won’t be affected when processing i." Won't we lose milk if we put firstly i, in case of that j sees that and loses milk? Or am I misunderstanding the task? </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-291157 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-291157 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-291157\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"309434\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/haleyk100198\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/416324/avatar/f2d97d505af17e9d.jpg'/> </a>\n <div><a href=\"/profile/haleyk100198\" title=\"Candidate Master haleyk100198\" class=\"rated-user user-violet\">haleyk100198</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/11/2016 06:32\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-309434\" href=\"?#comment-309434\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"309434\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"416324\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-309434\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I wonder how the problem Div1C can be converted to a segment tree lazy propagation implementation question, for trees like (1-2 2-3 3-4 4-5 .... 9999-E4) how can we achieve O(log N) update time?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-309434 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-309434 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-309434\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"310847\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/my_new_handle\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/233736/avatar/24128c61b65e3262.jpg'/> </a>\n <div><a href=\"/profile/my_new_handle\" title=\"Candidate Master my_new_handle\" class=\"rated-user user-violet\">my_new_handle</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/20/2016 14:49\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-310847\" href=\"?#comment-310847\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"310847\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"233736\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-310847\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>а зачем в таске б массив он влияет как-то?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-310847 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-310847 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-310847\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"332763\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/rhezo\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/305605/avatar/aa59e9c2ec688c6a.jpg'/> </a>\n <div><a href=\"/profile/rhezo\" title=\"Candidate Master rhezo\" class=\"rated-user user-violet\">rhezo</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Dec/24/2016 07:56\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-332763\" href=\"?#comment-332763\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"332763\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"305605\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-332763\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I'm getting Runtime Error on test 44 in <a href=\"//codeforces.com/problemset/problem/383/C\">Propogating Tree</a>. </p><p>This is because of stack overflow right? That test has N = 2e5 and for a straight chain of nodes, I'll get a runtime error with a recursive DFS right? What to do in such cases? </p><p>I can write an iterative DFS, but I do HLD recursively too and I'm not quite sure if I can write an iterative HLD. </p><p>Can anyone tell me what to do in such cases? I'm assuming that I got the runtime error due to stackoverflow from DFS.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-332763 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-332763 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-332763\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"346070\" commentParentId=\"332763\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/yinanzhu\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/520731/avatar/d61a58bf5df54146.jpg'/> </a>\n <div><a href=\"/profile/yinanzhu\" title=\"Expert yinanzhu\" class=\"rated-user user-blue\">yinanzhu</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/26/2017 07:18\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-346070\" href=\"?#comment-346070\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-332763\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"346070\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"520731\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-346070\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I used recursive dfs and passed all test case. Test 44 cost 1.5 s</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-346070 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-346070 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-346070\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"387028\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/blue__legend\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/blue__legend\" title=\"Expert blue__legend\" class=\"rated-user user-blue\">blue__legend</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/23/2017 07:16\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-387028\" href=\"?#comment-387028\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"387028\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"284949\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-387028\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>How to solve DIV 1 C using one fenwick or segment tree. The code link given in editorial is not working.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-387028 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-387028 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-387028\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"757423\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Ausmosian\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Ausmosian\" title=\"Expert Ausmosian\" class=\"rated-user user-blue\">Ausmosian</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/05/2021 15:05\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-757423\" href=\"?#comment-757423\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"757423\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"727283\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-757423\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>[<a href=\"https://codeforces.com/contest/383/problem/C\">384E — Propagating tree</a>] Can also be solved using Square Root Decomposition. <a href=\"https://codeforces.com/contest/383/submission/106526543\">Submission</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-757423 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-757423 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-757423\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"838255\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/3hill\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1621900/avatar/478297db63bad207.jpg'/> </a>\n <div><a href=\"/profile/3hill\" title=\"Expert 3hill\" class=\"rated-user user-blue\">3hill</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/11/2021 17:02\">2 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-838255\" href=\"?#comment-838255\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"838255\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1621900\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-838255\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I am Getting MLE on TC-53<br />Can someone review my code and figure out the issue ,Thanks</p> <ul> <li><a href=\"https://codeforces.com/contest/383/problem/C\">Problem</a></li> <li><a href=\"https://codeforces.com/contest/383/submission/128510633\">My code</a></li> </ul></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-838255 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-838255 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-838255\">\r\n </ul>\r\n</div>\r\n <br/>\r\n\r\n<div id=\"editBox-10547\" style=\"width:50em;display:none;\">\r\n <div class=\"previewBody\" style=\"border: 1px solid #d4d4d4; margin-bottom: 0.5em; padding: 0.25em; display:none;\"> </div>\r\n <div style=\"width: 1px\"> </div>\r\n <div class=\"commentLocale\" style=\"position: relative; top: 0.5em;left:4px;display: none;\">\r\n <input type=\"radio\" name=\"locale\" value=\"en\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In English</span>\r\n <input style=\"margin-left:1em\" type=\"radio\" name=\"locale\" value=\"ru\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In Russian</span>\r\n </div>\r\n <textarea data-drafts-id=\"CommentReplyFrame\" class=\"wysiwyg\" name=\"editContent\" rows=\"20\" style=\"width:99%;\"></textarea>\r\n <div class=\"error error__content\"></div>\r\n <div style=\"text-align:center;\">\r\n <input type=\"button\" name=\"preview\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Preview\"/>\r\n <input type=\"button\" name=\"save\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Save\"/>\r\n </div>\r\n</div>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n\r\nvar firstPreview10547 = true;\r\nvar lastPreviewContent10547 = '';\r\n\r\nif (!window.moveCommentRevision) {\r\n moveCommentRevision = function(e, dir) {\r\n var p = e.parent();\r\n var revisionCount = parseInt(p.attr(\"revisionCount\"));\r\n var revision = parseInt(p.attr(\"revision\"));\r\n var next = revision + dir;\r\n var commentId = p.attr(\"commentId\");\r\n if (next >= 1 && next <= revisionCount) {\r\n $.post(\r\n \"/data/comment-data\",\r\n {action: \"revision\", commentId: commentId, revision: next},\r\n function(json) {\r\n if (json.success == \"true\") {\r\n var parentDiv = e;\r\n\r\n while (parentDiv !== null && (parentDiv[0].nodeName.toLowerCase() !== \"td\" || !parentDiv.hasClass(\"right\"))) {\r\n parentDiv = parentDiv.parent();\r\n }\r\n\r\n if (parentDiv === null) {\r\n return;\r\n }\r\n\r\n parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\").html(json.content);\r\n Codeforces.setupSpoilers(parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\"));\r\n p.attr(\"revision\", next);\r\n p.find(\"span.revision\").text(next);\r\n if (next == 1) {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"visible\");\r\n }\r\n if (next == revisionCount) {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"visible\");\r\n }\r\n\r\n window.updateTypography();\r\n MathJax.Hub.Typeset();\r\n } else {\r\n alert(e.error);\r\n }\r\n },\r\n \"json\"\r\n );\r\n }\r\n };\r\n}\r\n\r\n$(\"div[commentableId=10547] a.leftRevision\").click(function () {\r\n window.moveCommentRevision($(this), -1);\r\n return false;\r\n});\r\n\r\n$(\"div[commentableId=10547] a.rightRevision\").click(function () {\r\n window.moveCommentRevision($(this), +1);\r\n return false;\r\n});\r\n\r\n\r\n\r\n });\n </script>\n\r\n\r\n <script src=\"//codeforces.org/s/81027/js/swfobject-2.2.min.js\" type=\"text/javascript\"></script>\n <script src=\"//codeforces.org/s/81027/js/ftaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n if (window.evercookie) {\n var ec = new evercookie({\n history: false,\n silverlight: false,\n baseurl: '',\n asseturi: '/assets',\n phpuri: '/2fdcd78',\n pngPath: '/eps',\n etagPath: '/ees',\n cachePath: '/ecs'\n });\n\n var randomNumber = function () {\n return Math.random().toString(36).substr(2);\n };\n\n var randomToken = function () {\n return (randomNumber() + randomNumber()).substring(0, 18);\n };\n\n window._ftaa = \"\";\n\n ec.get(\"70a7c28f3de\", function (value) {\n window._ftaa = value;\n if (!window._ftaa) {\n window._ftaa = randomToken();\n ec.set(\"70a7c28f3de\", window._ftaa);\n }\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n } else {\n window._ftaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\n <script src=\"//codeforces.org/s/81027/js/bfaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n var fpCallback = function() {\n Fingerprint2.get({}, function(components) {\n window._bfaa = Fingerprint2.x64hash128(components.map(function (pair) { return pair.value }).join(), 31);\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n };\n if (typeof Fingerprint2 !== 'undefined') {\n if (window.requestIdleCallback) {\n requestIdleCallback(fpCallback)\n } else {\n setTimeout(fpCallback, 500)\n }\n } else {\n window._bfaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"a.new-root-comment\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n\r\n $(\".comment-table .reply a\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".vote-for-comment\").mouseover(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").mouseout(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").click(function () {\r\n var vote = $(this);\r\n var commentId = $(this).parent().attr(\"commentid\");\r\n var commentRating = $(this).parent().attr(\"data-commentRating\");\r\n var direction = $(this).attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n $.post(\"/data/comment/vote\", {commentId: commentId, _tta: Codeforces.tta(), vote: direction, commentRating: commentRating}, function(data) {\r\n if (direction != 0 && !ownComment && data[\"success\"] == \"true\") {\r\n vote.parent().find(\".vote-for-comment\").attr(\"voteDirection\", 0);\r\n if (direction == 1)\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n else {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.closest(\".CommentVoteFrame\").find(\".ComplaintFrame\").css(\"display\", \"inline-block\");\r\n }\r\n vote.find(\"img\").attr(\"popacity\", \"1.0\");\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n vote.parent().find(\".commentRating\").html(data[\"commentRating\"]);\r\n }\r\n Codeforces.showMessage(data[\"message\"]);\r\n }, \"json\");\r\n return false;\r\n });\r\n\r\n $(\".negative-comment-vote\").closest(\".comment-table\").addClass(\"comment-bad\");\r\n\r\n $(\".troll-comment-vote\").closest(\".comment\").css(\"display\", \"none\");\r\n\r\n $(\".too-negative-comment-vote\").closest(\".comment-table\").each(function () {\r\n var e = $(this);\r\n e.addClass(\"comment-too-bad\");\r\n var commentId = e.attr(\"commentId\");\r\n $(\"<div class='bad-comment-replacement ttypography'>The comment is hidden because of too negative feedback, click <a href=# class=show-bad-comment-link>here</a> to view it</div>\").appendTo(\r\n e.find(\".right\")\r\n );\r\n e.find(\".comment-content\").hide();\r\n e.find(\".show-bad-comment-link\").click(function () {\r\n e.find(\".comment-content\").show();\r\n e.find(\".bad-comment-replacement\").hide();\r\n return false;\r\n });\r\n });\r\n });\n </script>\n </div>\r\n\r\n <style type=\"text/css\">\r\n .new-comments-box {\r\n padding: 0.5em;\r\n width: 22px;\r\n font-size: 1.3rem;\r\n font-weight: bold !important;\r\n\r\n position: fixed;\r\n top: 40%;\r\n right: 0;\r\n opacity: 0.2;\r\n color: white;\r\n text-align: center;\r\n\r\n border: 1px solid #222;\r\n background-color: #888 !important;\r\n border-radius: 3px;\r\n -moz-border-radius: 3px;\r\n -webkit-border-radius: 3px;\r\n }\r\n\r\n .new-comments-box:hover {\r\n opacity: 1;\r\n }\r\n\r\n .new-comments-box .dir:hover {\r\n background: #3B5998 !important;\r\n cursor: pointer;\r\n }\r\n </style>\r\n\r\n <div class=\"new-comments-box\" data-position=\"outside\" data-index=\"-1\" style=\"display: none;\">\r\n <div class=\"up dir\" title=\"Ctrl+Up\">↑<hr/>\r\n </div>\r\n <div class=\"info\" title=\"New comments\"></div>\r\n <div class=\"down dir\" title=\"Ctrl+Down\">\r\n <hr/>↓\r\n </div>\r\n </div>\r\n\r\n <script>\r\n $(\".show-archived-checkbox\").change(function () {\r\n const checked = $(this).is(\":checked\");\r\n $.post(\"/data/comment-data\", {action: \"setShowArchived\", checked}, function (json) {\r\n if (json[\"success\"] !== \"true\") {\r\n alert(json[\"error\"]);\r\n } else {\r\n if (checked) {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are now displayed\")\r\n } else {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are no longer displayed\")\r\n }\r\n }\r\n });\r\n return false;\r\n });\r\n\r\n function gotoComment(direction) {\r\n var box = $(\".new-comments-box\");\r\n var index = parseInt(box.attr(\"data-index\"));\r\n if (index == -1)\r\n index = 0;\r\n else\r\n index = Math.max(0, Math.min(parseInt(box.find(\".info\").text()) - 1, index + direction));\r\n box.attr(\"data-index\", index);\r\n var comment = $($(\".comment .highlight-blue[commentId]\").get(index));\r\n $('html, body').animate({\r\n 'scrollTop': Math.max(0, comment.offset().top - ($(window).height() - comment.height()) / 2)\r\n });\r\n return false;\r\n }\r\n\r\n $(\".new-comments-box .down\").click(function () {\r\n return gotoComment(1);\r\n });\r\n\r\n $(\".new-comments-box .up\").click(function () {\r\n return gotoComment(-1);\r\n });\r\n\r\n $(document).keydown(function (e) {\r\n var code = (e.keyCode ? e.keyCode : e.which);\r\n if (e.ctrlKey) {\r\n if (code == 38 || code == 40) {\r\n gotoComment(code - 39);\r\n }\r\n }\r\n });\r\n\r\n var newCommentCount = $(\".comment .highlight-blue[commentId]\").length;\r\n if (newCommentCount > 0) {\r\n $(\".new-comments-box .info\").text(newCommentCount);\r\n $(\".new-comments-box\").show();\r\n }\r\n\r\n $('table.comment-table').mouseenter(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").addClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n\r\n $('table.comment-table').mouseleave(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").removeClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n </script>\r\n\r\n\r\n\r\n <script>\r\n function adjustTopicComplainFrames() {\r\n let topicIds = [];\r\n\r\n $(\".has-topic-id\").each(function () {\r\n const $this = $(this);\r\n const topicId = $this.attr(\"topicId\");\r\n if (topicId) {\r\n topicIds.push(topicId);\r\n }\r\n });\r\n\r\n $.post(\"/data/topics\", {\r\n action: \"findComplainableTopicIds\",\r\n topicIds: topicIds.join(\",\")\r\n }, function (json) {\r\n if (json[\"success\"] === \"true\") {\r\n for (const topicId of json[\"complainableTopicIds\"].split(\",\")) {\r\n $(\".has-topic-id[topicId=\" + topicId + \"]\").each(function () {\r\n $(this).find(\".meta .ComplaintFrame\").css(\"display\", \"inline-block\");\r\n });\r\n }\r\n }\r\n }, \"json\");\r\n }\r\n\r\n $(function () {\r\n adjustTopicComplainFrames();\r\n })\r\n </script>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-10531\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 10531, _tta: Codeforces.tta(), topicRevisionId: 36233, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-10531\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 10531, _tta: Codeforces.tta(), topicRevisionId: 36233, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n </div>\r\n </div>\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 22:13:02</span> (h1).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/81027/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/81027/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/81027/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/81027/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-81027.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'81287584a8369d92',t:'MTY5NjcwNTk4Mi42NDcwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"}}},{"rowIdx":1939,"cells":{"problem_id":{"kind":"string","value":"384A"},"contest":{"kind":"string","value":"384"},"problem":{"kind":"string","value":"A"},"lang":{"kind":"string","value":"en"},"problem_title":{"kind":"string","value":"A. Coder"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">A. Coder</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Iahub likes chess very much. He even invented a new chess piece named Coder. A Coder can move (and attack) one square horizontally or vertically. More precisely, if the Coder is located at position <span class=\"tex-span\">(<i>x</i>, <i>y</i>)</span>, he can move to (or attack) positions <span class=\"tex-span\">(<i>x</i> + 1, <i>y</i>)</span>, <span class=\"tex-span\">(<i>x</i>–1, <i>y</i>)</span>, <span class=\"tex-span\">(<i>x</i>, <i>y</i> + 1)</span> and <span class=\"tex-span\">(<i>x</i>, <i>y</i>–1)</span>.</p><p>Iahub wants to know how many Coders can be placed on an <span class=\"tex-span\"><i>n</i> × <i>n</i></span> chessboard, so that no Coder attacks any other Coder.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains an integer <span class=\"tex-span\"><i>n</i></span> <span class=\"tex-span\">(1 ≤ <i>n</i> ≤ 1000)</span>.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>On the first line print an integer, the maximum number of Coders that can be placed on the chessboard.</p><p>On each of the next <span class=\"tex-span\"><i>n</i></span> lines print <span class=\"tex-span\"><i>n</i></span> characters, describing the configuration of the Coders. For an empty cell print an '<span class=\"tex-font-style-tt\">.</span>', and for a Coder print a '<span class=\"tex-font-style-tt\">C</span>'.</p><p>If there are multiple correct answers, you can print any.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>2<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>2<br/>C.<br/>.C<br/></pre></div></div></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"ff4dc53cb008291fde31cd567b69400f\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - A - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"2080925ccc752dc6d7cc9e06390b1986ca0eae39\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - A - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/73366/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/73366/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/73366/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/73366/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/73366/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/73366/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/73366/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/73366/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/73366/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/73366/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/73366/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/73366/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/73366/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/73366/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/sidebar-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/a037fe51637846d9c7c725713cd840ea/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='ff4dc53cb008291fde31cd567b69400f'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/73366/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/73366/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fcontest%2F384%2Fproblem%2FA%3Flocale%3Den\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"current\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='ff4dc53cb008291fde31cd567b69400f'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:100%;\"><a style=\"color: black\" href=\"/contest/384\">Codeforces Round 225 (Div. 2)</a></th>\n </tr>\n <tr>\n <td class=\"left bottom\" colspan=\"1\"><span class=\"contest-state-phase\">Finished</span></td>\n </tr>\n </tbody>\n </table>\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Practice?\n <div class=\"top-links\">\n </div>\n </div>\n<div>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Want to solve the contest problems after the official contest ends? Just register for practice and you will be able to submit solutions.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"\" method=\"post\"><input type='hidden' name='csrf_token' value='ff4dc53cb008291fde31cd567b69400f'/>\r\n <input type=\"hidden\" name=\"action\" value=\"registerForPractice\"/>\r\n <input type=\"submit\" name=\"submit\" value=\"Register for practice\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div> \r\n</div>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox ContestVirtualFrame borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Virtual participation <i class=\"sidebar-caption-icon las la-angle-down\"></i>\r\n\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\" \"\r\n\r\n data-page-url=\"/data/sidebarFrames\"\r\n\r\n>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests.\n\nIf you've seen these problems, a virtual contest is not for you - solve these problems in the archive.\n\nIf you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.\n\nNever use someone else's code, read the tutorials or communicate with other person during a virtual contest.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"/contest/384/virtual\" method=\"get\">\r\n <input type=\"submit\" name=\"submit\" value=\"Start virtual contest\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div>\r\n</div>\r\n <script>\r\n $(function () {\r\n $(\".ContestVirtualFrame .sidebar-caption-icon\").click(function() {\r\n $(this).toggleClass(\"la-angle-down la-angle-right\");\r\n const $target = $(this).parent().next();\r\n $target.toggle();\r\n const dataPageUrl = $target.attr(\"data-page-url\");\r\n const collapsed = $(this).hasClass(\"la-angle-right\");\r\n const params = {\r\n action: \"setCollapsed\",\r\n sidebarFrameSimpleClassName: \"ContestVirtualFrame\",\r\n collapsed\r\n };\r\n $.each($target[0].attributes, function(i, a) {\r\n const name = a.name;\r\n if (name.startsWith(\"data-extra-key-\")) {\r\n const key = a.value;\r\n const keyIndex = parseInt(name.substring(\"data-extra-key-\".length));\r\n const value = $target.attr(\"data-extra-value-\" + keyIndex);\r\n params[key] = value;\r\n }\r\n });\r\n $.post(dataPageUrl, params, function (result) {\r\n if (result[\"success\"] !== \"true\") {\r\n Codeforces.showMessage(\"Failed to save collapsed state.\");\r\n }\r\n }, \"json\");\r\n return false;\r\n });\r\n })\r\n </script>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Problem tags\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Implementation problems, programming technics, simulation\">\r\n implementation\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Difficulty\">\r\n *800\r\n</span>\r\n </div>\n <div style=\"clear:both;text-align:right;font-size:1.1rem;\">\r\n <span title=\"Please login into the Codeforces\" class=\"notice\">No tag edit access</span>\r\n </div>\r\n</div>\r\n </div>\n\r\n<form id=\"addTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='ff4dc53cb008291fde31cd567b69400f'/>\r\n <input name=\"action\" type=\"hidden\" value=\"addTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"5717\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<form id=\"removeTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='ff4dc53cb008291fde31cd567b69400f'/>\r\n <input name=\"action\" type=\"hidden\" value=\"removeTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"5717\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<script type=\"text/javascript\">\r\n $(\".tag-box img\").click(function () {\r\n var tagName = $(this).attr(\"value\");\r\n Codeforces.confirm(\"Are you sure you want to remove this tag?\", function () {\r\n $(\"#removeTagForm input[name=tagName]\").val(tagName);\r\n $(\"#removeTagForm\").submit();\r\n }, function () {\r\n }, \"Yes\", \"No\");\r\n });\r\n\r\n $(\"#addTagLink\").click(function () {\r\n $(this).hide();\r\n $(\"#addTagLabel\").show();\r\n return false;\r\n });\r\n\r\n $(\"#addTagSelect\").change(function () {\r\n var tagName = $(this).val();\r\n if (tagName === \"\") {\r\n $(\"#addTagLabel\").hide();\r\n $(\"#addTagLink\").show();\r\n } else {\r\n $(\"#addTagForm input[name=tagName]\").val(tagName);\r\n $(\"#addTagForm\").submit();\r\n }\r\n });\r\n</script>\r\n\r\n<style type=\"text/css\">\r\n#new-resource-form tr td {\r\npadding-top: 0.5em;\r\n}\r\n#new-resource-form input:not([type=\"submit\"]) {\r\nfont-size: 0.8em;\r\n}\r\n#new-resource-form select {\r\nfont-size: 0.8em;\r\n}\r\n.new-resource-error {\r\nfont-size: 0.8em;\r\n}\r\n.resource-locale {\r\ncolor: #666;\r\nfont-family: Consolas, \"Andale Mono WT\", \"Andale Mono\", \"Lucida Console\", \"Lucida Sans Typewriter\", \"DejaVu Sans Mono\", \"Bitstream Vera Sans Mono\", \"Liberation Mono\", \"Nimbus Mono L\", Monaco, \"Courier New\", Courier, monospace;\r\n}\r\n</style>\r\n<div class=\"roundbox sidebox sidebar-menu borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Contest materials\n<div class=\"top-links\">\n</div>\n</div>\n<ul>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/10448\" title=\"Codeforces Round #225\" target=\"_blank\">Codeforces Round #225</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"2168:2169\" resourceName=\"Announcement\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/10476\" title=\"Codeforces Round #225 — Editorial\" target=\"_blank\">Tutorial <span class=\"resource-locale\">(en)</span></a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"2173\" resourceName=\"Codeforces Round #225 — Editorial\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n</ul>\r\n</div></div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li class=\"current selectedLava\"><a\r\n href=\"/contest/384\">Problems</a></li>\r\n <li><a\r\n href=\"/contest/384/submit\">Submit Code</a></li>\r\n <li><a\r\n href=\"/contest/384/my\">My Submissions</a></li>\r\n <li><a\r\n href=\"/contest/384/status\">Status</a></li>\r\n <li><a\r\n href=\"/contest/384/hacks\">Hacks</a></li>\r\n <li><a\r\n href=\"/contest/384/room/1\">Room</a></li>\r\n <li><a\r\n href=\"/contest/384/standings\">Standings</a></li>\r\n <li><a\r\n href=\"/contest/384/customtest\">Custom Invocation</a></li>\r\n</ul>\r\n</div>\n\r\n <style>\r\n #facebox .content:has(.diff-popup) {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n }\r\n\r\n .testCaseMarker {\r\n position: absolute;\r\n font-weight: bold;\r\n font-size: 1rem;\r\n }\r\n\r\n .diff-popup {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n display: none;\r\n overflow: auto;\r\n }\r\n\r\n .input-output-copier {\r\n font-size: 1.2rem;\r\n float: right;\r\n color: #888 !important;\r\n cursor: pointer;\r\n border: 1px solid rgb(185, 185, 185);\r\n padding: 3px;\r\n margin: 1px;\r\n line-height: 1.1rem;\r\n text-transform: none;\r\n }\r\n\r\n .input-output-copier:hover {\r\n background-color: #def;\r\n }\r\n\r\n .test-explanation textarea {\r\n width: 100%;\r\n height: 1.5em;\r\n }\r\n\r\n .pending-submission-message {\r\n color: darkorange !important;\r\n }\r\n </style>\r\n <script>\r\n const OPENING_SPACE = String.fromCharCode(1001);\r\n const CLOSING_SPACE = String.fromCharCode(1002);\r\n\r\n const nodeToText = function (node, pre) {\r\n let result = [];\r\n\r\n if (node.tagName === \"SCRIPT\" || node.tagName === \"math\"\r\n || (node.classList && node.classList.contains(\"input-output-copier\")))\r\n return [];\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(OPENING_SPACE);\r\n }\r\n\r\n if (node.nodeType === Node.TEXT_NODE) {\r\n let s = node.textContent;\r\n if (!pre) {\r\n s = s.replace(/\\s+/g, \" \");\r\n }\r\n if (s.length > 0) {\r\n result.push(s);\r\n }\r\n }\r\n\r\n if (pre && node.tagName === \"BR\") {\r\n result.push(\"\\n\");\r\n }\r\n\r\n node.childNodes.forEach(function (child) {\r\n result.push(nodeToText(child, node.tagName === \"PRE\").join(\"\"));\r\n });\r\n\r\n if (node.tagName === \"DIV\"\r\n || node.tagName === \"P\"\r\n || node.tagName === \"PRE\"\r\n || node.tagName === \"UL\"\r\n || node.tagName === \"LI\"\r\n ) {\r\n result.push(\"\\n\");\r\n }\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(CLOSING_SPACE);\r\n }\r\n\r\n return result;\r\n }\r\n\r\n const isSpecial = function (c) {\r\n return c === ',' || c === '.' || c === ';' || c === ')' || c === ' ';\r\n }\r\n\r\n const convertStatementToText = function(statmentNode) {\r\n const text = nodeToText(statmentNode, false).join(\"\").replace(/ +/g, \" \").replace(/\\n\\n+/g, \"\\n\\n\");\r\n let result = [];\r\n for (let i = 0; i < text.length; i++) {\r\n const c = text.charAt(i);\r\n if (c === OPENING_SPACE) {\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"A\" data-uuid=\"ps_3c4b253a031e42ceed19afb8662f4d364eee9233\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">A. Coder</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Iahub likes chess very much. He even invented a new chess piece named Coder. A Coder can move (and attack) one square horizontally or vertically. More precisely, if the Coder is located at position <span class=\"tex-span\">(<i>x</i>, <i>y</i>)</span>, he can move to (or attack) positions <span class=\"tex-span\">(<i>x</i> + 1, <i>y</i>)</span>, <span class=\"tex-span\">(<i>x</i>–1, <i>y</i>)</span>, <span class=\"tex-span\">(<i>x</i>, <i>y</i> + 1)</span> and <span class=\"tex-span\">(<i>x</i>, <i>y</i>–1)</span>.</p><p>Iahub wants to know how many Coders can be placed on an <span class=\"tex-span\"><i>n</i> × <i>n</i></span> chessboard, so that no Coder attacks any other Coder.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains an integer <span class=\"tex-span\"><i>n</i></span> <span class=\"tex-span\">(1 ≤ <i>n</i> ≤ 1000)</span>.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>On the first line print an integer, the maximum number of Coders that can be placed on the chessboard.</p><p>On each of the next <span class=\"tex-span\"><i>n</i></span> lines print <span class=\"tex-span\"><i>n</i></span> characters, describing the configuration of the Coders. For an empty cell print an '<span class=\"tex-font-style-tt\">.</span>', and for a Coder print a '<span class=\"tex-font-style-tt\">C</span>'.</p><p>If there are multiple correct answers, you can print any.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>2<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>2<br />C.<br />.C<br /></pre></div></div></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=A]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== statementText) {\r\n $problem.find(\".diff-notifier\").show();\r\n\r\n $problem.find(\".diff-notifier-close\").click(function() {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n $problem.find(\".diff-notifier\").hide();\r\n });\r\n\r\n $problem.find(\"a.view-changes\").click(function() {\r\n $.post(\"/data/diff\", {action: \"getDiff\", a: previousStatementText, b: statementText}, function (result) {\r\n if (result[\"success\"] === \"true\") {\r\n Codeforces.facebox(\".diff-popup\", \"//codeforces.org/s/73366\");\r\n $(\"#facebox .diff-popup\").html(result[\"diff\"]);\r\n }\r\n }, \"json\");\r\n });\r\n }\r\n } else {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n }\r\n });\r\n });\r\n </script>\r\n\r\n\r\n<script type=\"text/javascript\">\r\n $(document).ready(function () {\r\n window.changedTests = new Set();\r\n\r\n function endsWith(string, suffix) {\r\n return string.indexOf(suffix, string.length - suffix.length) !== -1;\r\n }\r\n\r\n const inputFileDiv = $(\"div.input-file\");\r\n const inputFile = inputFileDiv.text();\r\n const outputFileDiv = $(\"div.output-file\");\r\n const outputFile = outputFileDiv.text();\r\n\r\n\r\n if (!endsWith(inputFile, \"standard input\")\r\n && !endsWith(inputFile, \"standard input\")) {\r\n inputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n if (!endsWith(outputFile, \"standard output\")\r\n && !endsWith(outputFile, \"standard output\")) {\r\n outputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n const titleDiv = $(\"div.header div.title\");\r\n\r\n\r\n\r\n String.prototype.replaceAll = function (search, replace) {\r\n return this.split(search).join(replace);\r\n };\r\n\r\n $(\".sample-test .title\").each(function () {\r\n const preId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n const cpyId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n\r\n $(this).parent().find(\"pre\").attr(\"id\", preId);\r\n const $copy = $(\"<div title='Copy' data-clipboard-target='#\" + preId + \"' id='\" + cpyId + \"' class='input-output-copier'>Copy</div>\");\r\n $(this).append($copy);\r\n\r\n const clipboard = new Clipboard('#' + cpyId, {\r\n text: function (trigger) {\r\n const pre = document.querySelector('#' + preId);\r\n const lines = pre.querySelectorAll(\".test-example-line\");\r\n return Codeforces.filterClipboardText(pre.innerText, lines.length);\r\n }\r\n });\r\n\r\n const isInput = $(this).parent().hasClass(\"input\");\r\n\r\n clipboard.on('success', function (e) {\r\n if (isInput) {\r\n Codeforces.showMessage(\"The example input has been copied into the clipboard\");\r\n } else {\r\n Codeforces.showMessage(\"The example output has been copied into the clipboard\");\r\n }\r\n e.clearSelection();\r\n });\r\n });\r\n\r\n $(\".test-form-item input\").change(function () {\r\n addPendingSubmissionMessage($($(this).closest(\"form\")), \"You changed the answer, do not forget to submit it if you want to save the changes\");\r\n const index = $(this).closest(\".problemindexholder\").attr(\"problemindex\");\r\n let test = \"\";\r\n $(this).closest(\"form input\").each(function () {\r\n const test_ = $(this).attr(\"name\");\r\n if (test_ && test_.substring(0, 4) === \"test\") {\r\n test = test_;\r\n }\r\n });\r\n if (index.length > 0 && test.length > 0) {\r\n const indexTest = index + \"::\" + test;\r\n window.changedTests.add(indexTest);\r\n }\r\n });\r\n\r\n $(window).on('beforeunload', function () {\r\n if (window.changedTests.size > 0) {\r\n return 'Dialog text here';\r\n }\r\n });\r\n\r\n autosize($('.test-explanation textarea'));\r\n\r\n $(\".test-example-line\").hover(function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n let top = 1E20;\r\n let left = 1E20;\r\n let problem = $(this).closest(\".problemindexholder\");\r\n $(this).closest(\".input\").find(\".\" + clazz).css(\"background-color\", \"#FFFDE7\").each(function() {\r\n top = Math.min(top, $(this).offset().top);\r\n left = Math.min(left, $(this).offset().left);\r\n });\r\n let testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n if (testCaseMarker.length === 0) {\r\n const html = \"<div class=\\\"testCaseMarker testCaseMarker_\" + end + \" notice\\\"></div>\";\r\n problem.append($(html));\r\n testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n }\r\n if (testCaseMarker) {\r\n testCaseMarker.show()\r\n .offset({top, left: left - 20})\r\n .text(end);\r\n }\r\n }\r\n }\r\n });\r\n }, function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n $(\".\" + clazz).css(\"background-color\", \"\");\r\n $(this).closest(\".problemindexholder\").find(\".testCaseMarker_\" + end).hide();\r\n }\r\n }\r\n });\r\n });\r\n\r\n });\r\n</script>\r\n\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 05:38:04</span> (j3).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/73366/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/73366/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/73366/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/73366/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-73366.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'8122c40a2d9e5aae',t:'MTY5NjY0NjI4NC4wNDEwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"},"long_tags":{"kind":"string","value":"[\"Implementation problems, programming technics, simulation\"]"},"short_tags":{"kind":"string","value":"[\"implementation\", \"*800\"]"},"tutorial_link":{"kind":"string","value":"https://codeforces.com/blog/entry/10476"},"tutorial_page":{"kind":"string","value":"\r\n\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"4f4c31ed5807bbee2a02378cf0944c06\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"h1\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Codeforces Round #225 — Editorial - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n \n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Codeforces Round #225 — Editorial - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/81027/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/81027/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/81027/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/81027/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/81027/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/81027/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/81027/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/81027/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/81027/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/81027/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/81027/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/81027/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/81027/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/81027/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/573cedc6b04c15481941f418269f4057/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='4f4c31ed5807bbee2a02378cf0944c06'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/81027/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fblog%2Fentry%2F10476\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='4f4c31ed5807bbee2a02378cf0944c06'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Pay attention\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n <div style=\"text-align:center;border-bottom: 1px solid rgb(185, 185, 185);margin:0 -0.5em 0.5em -0.5em;padding: 0 1em 0.5em 1em;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 1, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:51:58</span><br/><a href=\"/contestRegistration/1876\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n <div style=\"text-align:center;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 2, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:51:58</span><br/><a href=\"/contestRegistration/1877\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n\r\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div>\r\n\r\n\n <div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\n\r\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='4f4c31ed5807bbee2a02378cf0944c06'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n </label>\r\n </div>\r\n <div style=\"padding: 0 1em 1em 1em;text-align:right;\">\r\n <input style=\"height:1.65em;padding:0 0.75em;\" type=\"submit\" value=\"Find\"/>\r\n </div>\r\n </form>\r\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".handleBox\").autocomplete(\"/data/handles\", {\r\n delay: 200,\r\n width: 200,\r\n selectFirst: false,\r\n matchContains: true,\r\n minChars: 3\r\n });\r\n $(\".handleForm\").attr(\"autocomplete\", \"off\").submit(function () {\r\n var link = \"/profile/userHandle\".replace(\r\n \"userHandle\", $(this).find(\".handleBox\").val()\r\n );\r\n window.location = link;\r\n return false;\r\n });\r\n });\n </script>\n\r\n\r\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Recent actions\n <div class=\"top-links\">\n </div>\n </div>\n <div class=\"recent-actions\">\r\n <ul>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/121073\">Meta Hacker Cup 2023 Round 1</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/.Danet\" title=\"Expert .Danet\" class=\"rated-user user-blue\">.Danet</a> →\r\n <a href=\"/blog/entry/121172\">[TLE on pretest1]</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\" class=\"rated-user user-red\">Pyqe</a> →\r\n <a href=\"/blog/entry/121025\">Codeforces Round #902 (Div. 1, Div. 2, based on COMPFEST 15 — Final Round)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pranshu_Pandya\" title=\"Specialist Pranshu_Pandya\" class=\"rated-user user-cyan\">Pranshu_Pandya</a> →\r\n <a href=\"/blog/entry/121171\">An Interesting Tree Problem</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/sszcdjr\" title=\"Master sszcdjr\" class=\"rated-user user-orange\">sszcdjr</a> →\r\n <a href=\"/blog/entry/119859\">Codeforces Round 896 (Div. 1, Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/119880\">It's Happening! Meta Hacker Cup 2023 Schedule</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/DaviddeGea1\" title=\"Expert DaviddeGea1\" class=\"rated-user user-blue\">DaviddeGea1</a> →\r\n <a href=\"/blog/entry/70917\">Number of ways of dividing an array into 2 parts such that sum of each part is > k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bekh\" title=\"Master Bekh\" class=\"rated-user user-orange\">Bekh</a> →\r\n <a href=\"/blog/entry/74245\">Questions and doubts regarding Aliens DP trick</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a> →\r\n <a href=\"/blog/entry/8192\">Codeforces Round #190 — Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/hocky\" title=\"Candidate Master hocky\" class=\"rated-user user-violet\">hocky</a> →\r\n <a href=\"/blog/entry/95323\">FBHC wuining uw Day? Incwease uw stacc size! (ㅅ´ ˘ `)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/liouzhou_101\" title=\"International Master liouzhou_101\" class=\"rated-user user-orange\">liouzhou_101</a> →\r\n <a href=\"/blog/entry/87598\">Editorial of Codeforces Round #700</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/yeon_gist\" title=\"Newbie yeon_gist\" class=\"rated-user user-gray\">yeon_gist</a> →\r\n <a href=\"/blog/entry/121170\">plusMinusPermutation computing error</a>\r\n <img alt=\"Text created or updated\" title=\"Text created or updated\" src=\"//codeforces.org/s/81027/images/icons/x-update-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/altforminuscontribution\" title=\"Newbie altforminuscontribution\" class=\"rated-user user-gray\">altforminuscontribution</a> →\r\n <a href=\"/blog/entry/121162\">My screen get unexpectedly big, what should I do</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/atcoder_official\" title=\"Unrated, atcoder_official\" class=\"rated-user user-black\">atcoder_official</a> →\r\n <a href=\"/blog/entry/121120\">We will hold UNIQUE VISION Programming Contest 2023 Autumn(AtCoder Beginner Contest 323)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/YouStill_DontKnowMeYet\" title=\"Candidate Master YouStill_DontKnowMeYet\" class=\"rated-user user-violet\">YouStill_DontKnowMeYet</a> →\r\n <a href=\"/blog/entry/117659\">[GYM] Al-Baath Collegiate Programming Contest 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/ankancool\" title=\"Expert ankancool\" class=\"rated-user user-blue\">ankancool</a> →\r\n <a href=\"/blog/entry/121136\">Invitation to AstroByte 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/GeZhiyuan\" title=\"Grandmaster GeZhiyuan\" class=\"rated-user user-red\">GeZhiyuan</a> →\r\n <a href=\"/blog/entry/120943\">Codeforces Round 901 (Div. 1, Div. 2) Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a> →\r\n <a href=\"/blog/entry/120772\">PSA: Increase your stack size before the Meta Hacker Cup, here's how</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/dino_merlin\" title=\"Expert dino_merlin\" class=\"rated-user user-blue\">dino_merlin</a> →\r\n <a href=\"/blog/entry/121145\">Intuitive approach for CEOI Kangaroo?</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/icecuber\" title=\"Grandmaster icecuber\" class=\"rated-user user-red\">icecuber</a> →\r\n <a href=\"/blog/entry/70018\">CSES DP section editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bn00b\" title=\"Newbie Bn00b\" class=\"rated-user user-gray\">Bn00b</a> →\r\n <a href=\"/blog/entry/98820\">[FEATURE REQUEST : ATCODER] TOPICS TAGS AND SORTING BY SOLVE COUNT</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a> →\r\n <a href=\"/blog/entry/121163\">AtCoder Regular Contest 166 Announcement</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/windva\" title=\"Grandmaster windva\" class=\"rated-user user-red\">windva</a> →\r\n <a href=\"/blog/entry/120644\">Codeforces Round 899 (Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Misa-Misa\" title=\"Expert Misa-Misa\" class=\"rated-user user-blue\">Misa-Misa</a> →\r\n <a href=\"/blog/entry/121157\">Someone please help me understand this.</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/shivam565\" title=\"Specialist shivam565\" class=\"rated-user user-cyan\">shivam565</a> →\r\n <a href=\"/blog/entry/108348\">Total number of subarrays with sum atmost k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n </ul>\r\n </div>\r\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/recent-actions\">Detailed →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n</div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li><a\r\n href=\"/profile/fchirica\">fchirica</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/fchirica\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/fchirica\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/fchirica\">Submissions</a></li>\r\n <li><a\r\n href=\"/groups/with/fchirica\">Groups</a></li>\r\n <li><a\r\n href=\"/contests/with/fchirica\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/fchirica\">Problemsetting</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/fchirica\" style=\"text-decoration:none;color:black !important;\">fchirica's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"10531\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/10476\"> <p>Codeforces Round #225 — Editorial</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/fchirica\" title=\"Candidate Master fchirica\" class=\"rated-user user-violet\">fchirica</a>,\r\n <span class=\"format-humantime\" title=\"Jan/20/2014 22:18\">10 years ago</span>,\r\n \r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><h1><a href=\"/contest/384/problem/A\" title=\"Codeforces Round 225 (Div. 2)\">384A - Coder</a></h1><p>Usually, when you don’t have any idea how to approach a problem, a good try is to take some small examples.</p><p>So let’s see how it looks for N = 1, 2, 3, 4 and 5. With C I noted the coder and with * I noted an empty cell.</p><p><img alt=\" \" src=\"/predownloaded/8f/89/8f899efd227362957f283123a7927c7c8a300667.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>By now you should note that answer is N ^ 2 / 2 when N is even and (N ^ 2 + 1) / 2 when N is odd. Good. Generally, after you find a possible solution by taking examples, you need to prove it, then you can code it.</p><p>In order to proof it, one needs to do following steps:</p><p>1/ prove you can always build a solution having N ^ 2 / 2 (or (N ^ 2 + 1) / 2) pieces.</p><p>2/ prove that N ^ 2 / 2 (or (N ^ 2 + 1) / 2) is maximal number – no other bigger solution can be obtained.</p><p>For proof 1/ imagine you do coloring like in a chess table.</p><p><img alt=\" \" src=\"/predownloaded/50/12/50120d92bd0cea3d6a434d09ab4754ea20342351.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>The key observation is that by placing all coders on black squares of table, no two coders will attack. Why? Because a piece placed at a black square can attack only a piece placed at a white square. Again, why? Suppose chess table is 1-based. Then, a square (i, j) is black if and only if i + j is even. A piece placed at (i, j) can attack (i + 1, j), (i – 1, j) (i, j + 1) or (i, j – 1). The sum of those cells is i + j + 1 or i + j – 1. But since i + j is even, i + j + 1 and i + j – 1 are odd, hence white cells.</p><p>Depending on parity of N, number of black cells is either N ^ 2 / 2 or (N ^ 2 + 1) / 2. For N even, one can observe that there are equal amount of black and white cells. Total number of cells is N ^ 2, so number of black cells is N ^ 2 / 2. For N odd, number of black cells is number of white cells + 1. We can imaginary add a white cell to the board. Now, number of black cells will be also equal to number of white cells, so answer is (N ^ 2 + 1) / 2.</p><p>2/ Two coders attack each other if they are placed at two adjacent cells, one black and other one white. One needs to prove that adding more than number from 1/ will cause this to happen. If you place a coder at a white cell, you won’t be able to place at least one coder at a black cell, so in best case you don’t win anything by doing this. Hence, it’s optimally to place all coders on same color cells. Since cells colored in black are always more or equal to white ones, it’s always optimally to choose black color. But number from 1/ is the number of cells having black color. Adding one more piece will force you to add it to a white color cell. Now, you’ll have a piece placed at a black colored cell and one placed at an adjacent white colored cell, so two coders will attack. Hence, we can’t place more than number from 1/ pieces.</p><p>Code: <a href=\"http://pastie.org/8651801\">http://pastie.org/8651801</a></p><h1><a href=\"/contest/384/problem/B\" title=\"Codeforces Round 225 (Div. 2)\">384B - Multitasking</a></h1><p>Let’s start by saying when array A[] is sorted:</p><p>1/ is sorted in ascending order when i < j and A[i] <= A[j]. It is NOT sorted when i < j and A[i] > A[j].</p><p>2/ is sorted in descending order when i > j and A[i] <= A[j]. It is NOT sorted when i > j and A[i] > A[j].</p><p>Iahub can choose 2 indices i, j and swap values when A[i] > A[j]. If A[i] <= A[j], he’ll ignore operation. Hence, if he wants to sort all arrays in ascending order, he chooses indices i, j when i < j and perform operation. Otherwise, in all his operations he uses indices i, j such as i > j. A “good” operation is when choosing indices i < j for ascending order sorting and i > j for descending order sorting. By doing only good operations, after an array is sorted, it will stay sorted forever (for a sorted array, all good operations will be ignored).</p><p>From here we get our first idea: use any sorting algorithm you know and sort each array individually. When print swaps done by sorting algorithm chosen, print them as good operations. However, sorting each array individually can cause exceeding M * (M — 1) / 2 operations limit. Another possible solution would be, after you did an operation to an array, to update the operation to all arrays (you printed it, so it counts to M * (M — 1) / 2 operations limit; making it to all arrays will help sometimes and in worst case it won’t change anything). However, you need to code it very careful in order to make this algorithm pass the time limit. Doing this in a contest is not the best idea, especially when implementation could be complicated and you have no guarantee it will pass time limit.</p><p>So what else can we do? We can think out of box. Instead of sorting specific N arrays, you can sort all possible arrays of length M. Find a sequence of good operations such as, anyhow I’d choose an array of size M, it will get sorted ascending / descending.</p><p>I’ll show firstly how to do for ascending sorting. At position 1 it needs to be minimal element. Can we bring minimal element there using good operations? Yes. Just do “1 2” “1 3” “1 4” ... “1 M”. It basically compares element from position 1 to any other element from array. When other element has smaller value, swap is done. After comparing with all M elements, minimal value will be at position 1. By now on I’ll ignore position 1 and move to position 2. Suppose array starts from position 2. It also needs minimal value from array, except value from position 1 (which is no longer in array). Hence doing “2 3” “2 4” “2 5” ... “2 M” is enough, by similar reasons. For a position i, I need minimal value from array, except positions 1, 2, ..., i – 1. I simply do “i i+1” “i i+2” ... “i M-1” “i M”. By arriving at position i, array will be sorted ascending. The algorithm is simply:</p><p>for (int i = 1; i < M; ++i)</p><p>for (int j = i + 1; j <= M; ++j)</p><p>cout << i << “ “ << j << “\\n”;</p><p>This algorithm does exactly M * (M — 1) / 2 moves.</p><p>Can you find out how to sort array in descending order? Try to think yourself, then if you don’t get it read next. At first position of a descending array it needs to be maximal value. Similarly to ascending order, we can do “2 1” “3 1” “4 1” ... “M 1”. When I’m at a position i and I compare its value to value from position 1, doing operation “i 1” checks if A[i] > A[1]. If so, it swaps A[i] and A[1], so position 1 will contain now the maximum value so far. Similarly to logic from ascending order, when I’m at position i, I need maximum value from array except positions 1, 2, ..., i – 1, so I do “i+1 i” “i+2 i” ... “M i”. Algorithm is:</p><p>for (int i = 1; i < M; ++i)</p><p>for (int j = i + 1; j <= M; ++j)</p><p>cout << j << “ “ << i << “\\n”;</p><p>Obviously, this does as well M * (M — 1) / 2 operations worst case. All algorithm is about 10 lines of code, much better than other solution, which requires two manually sorts and also has a chance to exceed TL.</p><p>Code: <a href=\"http://pastie.org/8651809\">http://pastie.org/8651809</a></p><h1><a href=\"/contest/384/problem/C\" title=\"Codeforces Round 225 (Div. 2)\">384C - Milking cows</a></h1><p>A good strategy to approach this problem is to think how optimal ordering should look like. For this, let’s calculate for each 2 different cows i and j if cow i needs to be milked before or after cow j. As we’ll show, having this information will be enough to build optimal ordering. It is enough to consider only cases when i < j, case when i > j is exactly the opposite of case i < j. For formality, I’ll call the optimal ordering permutation and lost milk the cost of permutation.</p><p>So, for an optimal permutation P let’s take 2 numbers i < j and see in which cases i should appear before j in permutation (i is before j if P[pos1] = i, P[pos2] = j and pos1 < pos2; otherwise we’ll call i is after j). We have 4 possible cases:</p><p>1/ A[i] = 0 and A[j] = 0</p><p>If we put i before j, no additional cost will be added. Since j is in right of i and i only adds cost when it finds elements in left of i, j won’t be affected when processing i. When processing j, i will be already deleted so it won’t affect the cost either. Hence, we can put i before j and no cost will be added.</p><p>2/ A[i] = 0 and A[j] = 1</p><p>Here, i and j can appear in arbitrary order in permutation (i can be before or after j). No matter how we choose them, they won’t affect each other and cost will remain the same.</p><p>3/ A[i] = 1 and A[j] = 0</p><p>As well, here i and j can appear in arbitrary order. If we choose i first, j will be in right of it, so cost of permutation will increase by one. If we choose j first, i will be in left of it so cost of permutation will increase as well. No matter what we do, in this case cost of permutation increases by 1.</p><p>4/ A[i] = 1 and A[j] = 1</p><p>Here, i needs to be after j. This adds 0 cost. Taking i before j will add 1 cost to permutation (since j is in right of i).</p><p>Those 4 cases show us how a minimal cost permutation should look. In a permutation like this, only case 3/ contributes to final cost, so we need to count number of indices i, j such as i < j and A[i] = 1 and A[j] = 0 (*). If we show a permutation following all rules exists, task reduces to (*).</p><p>By cases 2/ and 3/ it follows that in an optimal permutation, it only matters order of elements having same value in A[]. We can put firstly all elements having value 0 in A[], then all elements having value 1 in A[]. We can order elements having value 0 by case 1/ and elements having value 1 by case 4/. More exactly, suppose i1 < i2 < ... < im and (A[i1] = A[i2] = ... = A[im] = 0) and j1 > j2 > ... > jn (A[j1] = A[j2] = ... = A[jn] = 1). Then, a permutation following all rules is {i1, i2, ..., im, j1, j2, ..., jn}. This permutation can always be built.</p><p>Hence, task reduces to (*): count number of indices i, j such as i < j and A[i] = 1 and A[j] = 0. We can achieve easily an O(N) algorithm to do this. Let’s build an array cnt[j] = number of 0s in range {j, j + 1, ..., N} from array A. We can easily implement it by going backwards from N to 1. The result is sum of cnt[i], when A[i] = 1.</p><p>Code: <a href=\"http://pastie.org/8651813\">http://pastie.org/8651813</a></p><h1><a href=\"/contest/384/problem/D\" title=\"Codeforces Round 225 (Div. 2)\">384D - Volcanoes</a></h1><p>Our first observation is that if there is a path from (1, 1) to (N, N), then the length of path is 2 * N – 2. Since all paths have length 2 * N – 2, it follows that if there is at least one path, the answer is 2 * N – 2 and if there isn’t, the answer is -1. How to prove it? Every path from (1, 1) to (N, N) has exactly N – 1 down directions and exactly N – 1 right directions. So, total length for each path is N – 1 + N – 1 = 2 * N – 2. </p><p>So we reduced our problem to determine if there is at least one path from (1, 1) to (N, N). This is the challenging part of this task, considering that N <= 10 ^ 9. How would you do it for a decently small N, let’s say N <= 10^3 . One possible approach would be, for each row, keep a set of reachable columns. We could easily solve this one by doing this: if (i, j) denotes element from ith row and jth column, then (i, j) is (is not) reachable if:</p><p>if (i, j) contains a volcano, then (i, j) is not reachable. Otherwise, if at least one of (i – 1, j) and (i, j – 1) is reachable, then (i, j) is reachable. Otherwise, (i, j) is not reachable.</p><p>What’s the main problem of this approach? It needs to keep track of 10^9 lines and in worst case, each of those lines can have 10^9 reachable elements. So, worst case we need 10^9 * 10^9 = 10^18 operations and memory.</p><p>Can we optimize it? We can note for beginning that we don’t need to keep track of 10^9 lines, only m lines are really necessarily. We need only lines containing at least one obstacle (in worst case when each line contains only one obstacle, we need m lines). How to solve it this way? Suppose line number x contains some obstacles and lines x + 1, x + 2, x + 3 do not contain any obstacle. Suppose we calculated set S = {y | cell (x, y) is reachable}. How would look S1, S2, S3 corresponding to lines x + 1, x + 2, x + 3? For S1, we can reach cell (x + 1, ymin), where ymin is minimal value from set S. Then, we can also reach {ymin + 1, ymin + 2, ..., N}, by moving right from (x + 1, ymin). So S1 = {ymin, ymin + 1, ..., N}. How do S2 and S3 look? It’s easy to see that they’ll be as well {ymin, ymin + 1, ..., N}. So we get following optimization: suppose set of lines containing at least one obstacle is {L1, L2, ..., Lk}. We need to run algorithm only for lines L1, L1 + 1, L2, L2 + 1, L3, L3 + 1, ..., Lk, Lk + 1.</p><p>It looks like we didn’t make anything with this optimization. Even if we calculate for m lines, each line can still have 10^9 reachable positions. So worst case we perform 10^14 operations. We need something better for managing information from a line. You can note that for a given line y, there are a lot of positions having consecutive values. There are a lot of positions (x, y) and (x, y + 1) both reachable. This should give us following idea: what if instead of keeping reachable positions, we keep reachable ranges? That is, for each line x we keep a set of ranges S = {(a, b) | all cells (x, k) with a <= k <= b are reachable}. </p><p>How many ranges can it be for a line? If the line contains m obstacles, there are m + 1 ranges. Suppose for line x all cells are reachable, but for line x + 1 cells (x + 1, 3) (x + 1, 5) (x + 1, N – 1) are blocked. Then, the ranges of reachable cells are [1, 2] [4, 4], [6, N – 2] and [N, N]. By now, we get worst case m lines and worst case each line having m elements, so in worst case we’d have to handle m * m = 10 ^ 10 events. This may still look too much, but happily this bound is over estimated. If a line has o obstacles, there can be at most o + 1 ranges. If lines L1, L2, ..., Lk have {o1, o2, ..., ok} obstacles, there’ll be at most o1 + o2 + ... + ok + k ranges. But o1 + o2 + ... + ok = m and also k is at most m (proved above why we’re interested in at most m lines), so in worst case we get m + m = 2 * m ranges. Yaay, finally a decent number of states for this problem :)</p><p>So, we iterate each line we’re interested in. Let’s find set of ranges for this line, thinking that all cells from line above are reachable. This is easy to do. After we get our ranges like all cells from above can be visited, let’s think how having obstacles above can influence current ranges. After adding ranges from above, current ranges can’t increase (obviously), they can only decrease, remain the same or some of them can become empty. So, let’s take each range [a, b] from current line and see how it will transform after adding ranges from previous line. </p><p>Given range [a, b], it can transform only in [a’ , b] with a’ >= a. If a’ > b, then obviously range is empty. Why second number of range keeps constant? Let a’ smallest reachable column from current line which is in range [a, b]. It’s enough to check a’ >= a, as if a’ > b, range will be empty. It’s obviously why we need to keep a’ smallest value possible >= a: we’re interested to keep range as big as possible and as less as we cut from left, as big it is. Once we’ve found a’ in range [a, b] (or a’ > b if range is empty) all cells {a’ + 1, a’ + 2, ..., b} are reachable as well by going right from a’, so if interval is not empty, then second number defining it remains b.</p><p>Next question is how to find a’ fast enough. In order a point a’ to be reachable on current range, it also needs to exist a range on previous line containing it. If the range from previous line is [pa, pb] then a’ needs to follow 3 conditions:</p><p>a’ minimal such as</p><p>pa <= a’ <= pb</p><p>a’ >= a</p><p>What if instead of finding a’ we find [pa, pb]? Then a’ is max(pa, a). In order a’ to be as small as possible, since a is constant, pa needs to be as small as possible. So we reduced it to:</p><p>pa minimal pb >= a’ >= a <=> pb >= a</p><p>Intervals from previous line are disjoint, no 2 intervals cross each other. It means that if pb is minimal, than pa is minimal too (if we increase pb, then pa will increase too, so it won’t be minimal). Hence, you need to find an interval [pa, pb] such as pb is minimal and pb >= a. Then, a’ is max(a, pa). This is easy to do if we sort all intervals from previous line increasing by second value (pb), then we binary search for value a. </p><p>Finally, after running algorithm for all lines, last range from last line has second number N (assuming ranges are sorted increasing by second value), then there exist a path, otherwise there does not exist. This algorithm should run O(m * logm) worst case, good enough to pass. </p><p>Code: <a href=\"http://pastie.org/8651817\">http://pastie.org/8651817</a></p><h1><a href=\"/contest/384/problem/E\" title=\"Codeforces Round 225 (Div. 2)\">384E - Propagating tree</a></h1><p>This is kind of task that needs to be break into smaller subproblems that you can solve independently, then put them together and get solution.</p><p>Let’s define level of a node the number of edges in the path from root to the node. Root (node 1) is at level 0, sons of root are at level 1, sons of sons of root are at level 2 and so on.</p><p>Now suppose you want to do an operation of type 1 to a node x. What nodes from subtree of x will be added +val (a positive value)? Obviously, x will be first, being located at level L. Sons of x, located at level L + 1 will be added –val. Sons of sons, located at level L + 2, will be added value +val again. So, nodes from subtree of x located at levels L, L + 2, L + 4, ... will be added a +val, and nodes located at levels L + 1, L + 3, L + 5 will be added a –val. Let’s take those values of L modulo 2. All nodes having remainder L modulo 2 will be added a +val, and nodes having reminder (L + 1) modulo 2 will be added –val. In other words, for a fixed x, at a level L, let y a node from subtree of x, at level L2. If L and L2 have same parity, +val will be added to y. Otherwise, -val will be added to y.</p><p>From here we have the idea to split nodes of tree in 2 sets – those being located at even level and those being located at odd level. What still makes the problem hard to solve? The fact that we have a tree. If nodes from a subtree would be a contiguous sequence instead of some nodes from a tree, problem would be simpler: the problem would reduce to add / subtract values to all elements of a subarray and query about a current value of an element of array. So, how can we transform tree to an array, such as for a node x, all nodes from subtree of x to be a subarray of array?</p><p>The answer is yes. We can do this by properties of DFS search. Before reading on, make sure that you know what is discovery time and finish time in a DFS search. Let’s build 3 arrays now – discover[], representing nodes in order of their discover times (a node is as before in discover as it has a small discover time), begin[] = for a node, in which time it was discovered and end[] = what’s last time of a discovered node before this node finishes. For a subtree of x, all nodes in the subtree are nodes in discover from position begin[x] to end[x].</p><p>Example: suppose you have tree 1-5; 1-6; 6-7; 6-4; 4-2; 4-3</p><p>Discover is {1, 5, 6, 7, 4, 2, 3}.</p><p>begin is {1, 6, 7, 5, 2, 3, 4}.</p><p>end is {7, 6, 7, 7, 2, 7, 4}.</p><p>What’s subtree of node 6? elements of discover from position begin[6] to end[6]. In this case, from 3 to 7, so elements {6, 7, 4, 2, 3}. You can see it’s correct and take more examples if you want :)</p><p>Now, we reduced problem to: you’re given an array A. you can perform 2 operations:</p><p>1/ increase all elements from a range [x, y] to a value val (val can be negative, to treat subtractions)</p><p>2/ what’s current value of an element from position pos.</p><p>Those who solved “Iahub and Xors” from my last round, CF 198, should probably say they saw something similar before. If you didn’t solve problem before, I encourage you to do it after you solve this one, it uses a similar idea to what will follow now. Also, if you don’t know Fenwick trees, please read them before moving on. An alternative would be for this task using segment trees with lazy update, but I see this one more complicated than needed.</p><p>I’ll use now a not so common approach when dealing with data structures. Instead of keeping in a node the result, like you usually do, I’ll keep just an auxiliary information. So what algorithm proposed does:</p><p>Let A an array, initially with all elements 0.</p><p>When you need to update range [x, y] with value val, you simply do A[x] += val and A[y + 1] -= val.</p><p>When you need to answer a query about position pos, you output A[1] + A[2] + ... + A[pos].</p><p>Implemented brute force, you get O(1) per update and O(N) per query. However, these both are operations supported by a Fenwick tree, so you can get O(logN) per operation.</p><p>It may not be very clear why this algorithm works. Let’s take a closer look: an update needs to add value val only to range [x, y]. When you query a position pos, let’s see if algorithm handles it correctly:</p><p>1/ pos < x. In this case, result must not be affected by my update. Since pos < x and I only updated 2 values with indices >= x, when doing A[1] + A[2] + ... + A[pos] it won’t matter at all I did that update – at least not for this query.</p><p>2/ x <= pos <= y. Here, for a pos, I need to add value val only once. We add it only at A[x] – in this way it will be counted once, and it will be considered for each elements from range [x, y] (since an element at position p from range [x, y] has p >= x, in A[1] + A[2] + ... + A[p] I’ll have to consider A[x]).</p><p>3/ pos > y. Here I don’t have to consider the query. But it would be considered when processing A[x]. But if I add to A[y + 1] value –val I’ll just cancel the value previously added.</p><p>Code (actually we use just one Fenwick tree instead of 2, can you think why it works? :) ) : <a href=\"http://pastie.org/8651824\">http://pastie.org/8651824</a></p><h1><a href=\"/contest/383/problem/D\" title=\"Codeforces Round 225 (Div. 1)\">383D - Antimatter</a></h1><h2>Author's solution</h2><p>The problem is: given an array, iterate all possible subarrays (all possible elements such as their indexes are consecutive). Now, for a fixed subarray we need to know in how many ways we can color its elements in black and white, such as sum of black elements is equal to sum of white elements. The result is sum of this number, for each subarray.</p><p>Let’s solve an easier problem first. This won’t immediately solve the harder version, but it will be useful later. Suppose you’ve fixed a subarray. In how many ways can you color it with black and white? Suppose subarray has N elements and sum of them is M. Also, suppose for a coloring, sum of blacks is sB and sum of whites is sW. For coloring to be valid, sB = sW. But we also know that sB + sW = M (because each element is colored by exactly one color). We get that 2 * sB = M, so sB = M / 2. The problem is now: in how many ways can we color elements in black such as sum of blacks is M / 2 (after we fix a black coloring, we color with white non colored elements; sum of white colored elements is also M / 2). This is a well known problem: Knapsack problem. Let ways[i][j] = in how many ways one can obtain sum j from first i elements. When adding (i + 1) object, after ways[i] is calculated, for a fixed sum j we can do 2 things: add (i + 1) object to sum j or skip it. Depending of what we chosen, we add value ways[i][j] to ways[i + 1][j + value[i + 1]] or to ways[i + 1][j]. The result is in ways[N][M / 2]. This works in O(N * M) time.</p><p>An immediate solution can be obtained now: take all subarrays and apply above approach. This leads to an O(N ^ 2 * M ^ 2) solution, which is too much. One can reduce complexity to O(N ^ 2* M) by noting that processing subarray [i, j] can be done with already calculated values for subarray [i, j – 1]. Hence, instead of adding N elements, it’s enough to add 1 element to already calculated values (element from position j). Sadly, O(N ^ 2 * M) is still too slow, so we need to find something better. The solution presented below will look forced if you didn’t solve some problems with this technique before. It’s hard to come with an approach without practicing this kind of tasks. But don’t worry, as much as you practice them, as easily you’ll solve those problems.</p><p>We’ll solve task by divide and conquer. Complexity of this solution is O(N * M * logN). Let f(left, right) a function that counts number of colorings for each subarray [i, j], such as subarray [i, j] is included in subarray [left, right] (left <= i <= j <= right). Answer is in f(1, N). The trick is to define a value med = (left + right) / 2 (very frequent trick in divide and conquer problems, called usually a median). We can next classify [i, j] subarrays in 3 types:</p><p>1/ i <= med j <= med</p><p>2/ i > med j > med</p><p>3/ i <= med j > med</p><p>We can solve 1/ and 2/ by calling f(left, med) and f(med + 1, right). The remained problem is when i <= med and j > med. If we solve 3/ in O((right – left) * M) time, this will be enough to overall achieve O(N * M * logN) (for this moment trust me, you’ll see later why it’s so :) ).</p><p>Let’s denote by i1 last i1 elements from subarray [left, med]. Also, let’s note by i2 first i2 elements from subarray [med + 1, right]. For example, let left = 1 and right = 5, with array {1, 2, 3, 4, 5}. med is 3 and for i1 = 2 and i2 = 1, “left” subarray is {2, 3} and “right” subarray is {4}. By iterating i1 from 1 to med – left + 1 and i2 from 1 to right – med and then unite subarrays i1 and i2, we obtain all subarrays described in 3/ . Let’s denote by j1 sum of a possible black coloring of i1. Similarly, j2 is sum of a possible black coloring of i2.</p><p>Suppose we fixed i1, i2, j1 and j2. When it’s the coloring valid? Let S sum of united subarrays i1 and i2 (S = value[med – i1 + 1] + value[med – i1 + 2] + ... + value[med] + value[med + 1] + ... + value[med + i2 – 1] + value[med + i2]). Now it’s time to use what I explained at the beginning of solution. The coloring is good only when j1 + j2 = S / 2. We can rewrite the relation as 2 * (j1 + j2) = sum_of_elements_from_i1 + sum_of_elements_from_i2. We can rewrite it even more:</p><p>2 * j1 + 2 * j2 — sum_of_elements_from_i1 — sum_of_elements_from_i2 = 0</p><p>2 * j1 – sum_of_elements_from_i1 = sum_of_elements_from_i2 – 2 * j2 = combination_value</p><p>This relation is the key of solving problem. You can see now that relation is independent in “left” and “right” side. We calculate left[i1][j1] and right[i2][j2] = in how many ways can I obtain sum of blacks j1 (j2) from first i1 (i2) from left (right) side. Let’s calculate also count[value] = in how many ways can I obtain combination_value equal to value in the right side. For some fixed (i2, j2) I add to count[sum_of_elements_from_i2 – 2 * j2] value right[i2][j2]. In this way count[] is calculated correctly and completely. Now, let’s fix a sum (i1, j1) in the left side. We’re interested how many good colorings are such as there exist a coloring of j1 in i1 elements (the endpoint of “left” is fixed to be i1 and I need to calculate endpoints i2 for right, then to make colorings of i2). A coloring is good if combination_value of (i1, j1) and (i2, j2) is equal. Hence, I need to know in how many ways I can color i1 elements to obtain sum j1 and also I need to know in how many ways I can color elements from right to obtain same combination_value as it’s in the left. It’s not hard to see that answer for a fixed (i1, j1) is left[i1][j1] * count[2 * j1 – sum_of_elements_from_i1]. This takes O((right – left) * M) time.</p><p>The only thing remained in the problem is to see why complexity is O(N * M * logN). We can assume N is a power of 2 (it not, let’s round N to smallest power of 2 bigger than N; complexity for N is at least as good as complexity for this number). Draw a binary complete tree with N nodes. Each node corresponds to an appeal of f(). For a level, exactly O(N * M) operations are performed. To see why:</p><p>For level 1, there’ll be 1 node performing N * M operations.</p><p>For level 2, there’ll be 2 nodes performing (N / 2) * M operations. Summing up we get O(N * M).</p><p>For level 3, there’ll be 4 nodes performing (N / 4) * M operations. Summing up we get O(N *M) as well.</p><p>and so on.</p><p>So for each level we perform O(N * M) operations. A binary complete tree has maximum O(logN) levels, so overall complexity is O(N * M * logN).</p><p>Code: <a href=\"http://pastie.org/8651826\">http://pastie.org/8651826</a></p><h2>Solution fount by contestants</h2><p>This was totally unexpected to us :) Good job finding it, you guys are really smart. </p><p>We observe that x units of antimatter is the same thing as -x units of matter. Then we can consider that an element produces either x or -x units of matter. A valid substring is one that can have the sum of the elements 0. The problem is reduced to finding how many different substrings can we have with sum 0 (a substring is different than another one if it has different indices, or if at least one element produces matter in one and antimatter in the other).</p><p>This problem can be solved with dynamic programming. We will hold D[i][j] = the number of substrings that end in element i, and have sum j. It's easy to see that D[i + 1][j] = D[i][j — x] + D[i][j + x], where x is the value of the current element (we can put either -x or x). After we finish computing all the values for current i, we add to the solution D[i][0] (how many valid substrings do we have). After that, we add 1 to D[i][0], meaning that there is an empty substring starting at position i (however, we don't need to add it to the answer).</p><p>For a code, check passing submissions during contest. </p><h2><a href=\"/contest/383/problem/E\" title=\"Codeforces Round 225 (Div. 1)\">383E - Vowels</a></h2><h2>Author's solution</h2><p>Let's iterate over all possible vowel sets. For a given set {x1, x2, ..., xk} we're interested in number of correct words from dictionary. After a precalculation, we can do it in O(k).</p><p>Suppose our current vowel set is {x1, x2, ..., xk}. How many words are covered by the current vowels? By definition, we say a word is covered by a set of vowels if at least one of 3 letters of word is in vowel set. We can calculate this number using principle of inclusion and exclusion. We’ll denote by |v1, v2, v3, ...| = number of words containing ALL of vowels v1, v2, v3, ... . Using principle of inclusion and exclusion we get:</p><p>number_of_words_covered = |x1| + |x2| + .. + |xk| — |x1, x2| — |x1, x3| — .... + |x1, x2, x3| + |x1, x2, x4| + .... + |xk-2, xk-1, xk|. This formula is simply a reformulation of principle of inclusion and exclusion. You can easily observe that |v1, v2, ..., vk| makes sense only when k is at most 3, as no word from input can contain 4 or more letters (and hence can’t contain 4 or more vowels). </p><p>Example:</p><p>Suppose words are abc, abd and bcd. </p><p>|a| = 2 (first 2 words both contain character a).</p><p>|a, b| = 2 (as well, first 2 words contain characters a and b).</p><p>|b| = 3 (all 3 words contain character b).</p><p>|a, b, d| = 1 (only second word contains all 3 characters).</p><p>Also, note how principle of inclusion and exclusion works. number of words covered for vowels {a, b} is |a| + |b| — |a, b| = 2 + 3 – 2. Indeed, answer is 3.</p><p>We divide our problem in 3 subproblems. First one, for a vowel set, compute sum of |a|, where a is a letter from subset. Second, compute sum of |a, b|, where both a and b are letters from set. Third, compute sum of |a, b, c|, where a, b, c are letters from set. As stated, the answer is number_from_1st_step + number_from_3rd_step – number_from_2nd_step. If you followed me, you’ll see that we want to compute results for each subproblem in O(queryLetters).</p><p>First subproblem can be solved trivially in O(queryLetters). Let array single[], with following meaning: single[c] is how many words contain character c. It can be trivially precomputed in O(24 * N). Note that if a word contains twice/third times a character c, it needs to be counted only one (e.g. word aba will add only 1 to single[a]). For compute result of this subproblem for a given set of vowels, I’ll take all letters from set. If letter belongs to set, I add to result single[letter]. This step can be also be solved in O(1), but there’s no need, since other subproblems allow only an O(queryLetters) solution. </p><p>For second and third subproblems it’s a little more difficult. I’ll present here how to solve second subproblem and some hints for third one (if you understand second, with hints you should be able to solve third one by your own).</p><p>Similarly to first step, I’ll define a matrix double[c1][c2] = how many words contain both characters c1 and c2. A trivially solution would be, for a given vowel set, take all combinations of letters c1 and c2 that belong to set and add to result value double[c1][c2]. However, this solves each query in O(queryLetters^2), which is too slow.</p><p>Note, if we’d have 12 letters, instead of 24, this approach would be fast enough. From here it comes a pretty classical idea in exponential optimization: meet in the middle attack. We split those 24 letters in 2 groups: first 12 letters and last 12 letters. The answer for a subset is sum of double[c1][c2] (when c1 and c2 belong to current vowel set) when</p><p>1/ c1 and c2 belong to first 12 letters</p><p>2/ c1 and c2 belong to last 12 letters</p><p>3/ c1 belongs to first 12 letters and c2 belongs to last 12 letters</p><p>1/ and 2/ can be immediately precalculated as stated above, in O(2 ^ 12 * 12 ^ 2). We’ll remember results for each half using bitmasks arrays. Let Half1[mask] = sum over double[c1][c2], when c1 and c2 are in first 12 letters and correspond to 1 bits of mask. Half2[mask] is defined similarly, but for last 12 letters (e.g. subset {a, c, d} corresponds to bitmask 2^0 + 2^2 + 2^3 = 13 in first half and subset {m, n, p} corresponds to bitmask 2^0 + 2^1 + 2^3 = 11 for second half). Now, for a given subset, one can answer first 2 parts in O(queryCount) worst case (read input for a query and convert it to bitmasks). </p><p>How to answer 3? With another precalculation, of course. We know c1 letter needs to be in first 12 letters and c2 needs to be in last 12 letters. The precalculation we do here is: mixed_half[mask][i] = sum over |c1, c2|, when c1 belongs to first half and is a 1 bit of mask and c2 is i-th character of second half. Hence, for a query, we can fix character from second half (c2, by iteration of query letters from second half) and know sums of |c1, c2| between it and all available characters from first half after we do this precalculation. Also, precalculation is done trivially in O(2 ^ 12 * 12^2): fix mask, fix i and then iterate over 1 bits from mask and add double[c1][c2]. </p><p>Third subproblem is left, but it can be done similarly to second one. Instead of double[c1][c2], we’ll have triple[c1][c2][c3] = how many words contain all 3 characters c1, c2 and c3? We also do meet in the middle here, divide those 24 letters into 2 sets of 12 letters. We have 4 cases:</p><p>1/ c1, c2, c3 belong to first half</p><p>2/ c1, c2, c3 belong to second half</p><p>3/ c1, c2 belong to first half and c3 to second half</p><p>4/ c1 belongs to first half and c2, c3 to second half</p><p>1/ and 2/ are done brute force, like in second subproblem (the only difference is we choose 3 characters instead of 2, having complexity O(2 ^ 12 * 12 ^ 3)). For 3/ and 4/ we also precompute 2 matrixes: </p><p>mixed_two_one[mask][i] = c1 and c2 belong to mask from first half and c3 is i-th character from second half </p><p>and </p><p>mixed_one_two[mask][i] = c1 is i-th character from first half and c2, c3 belong to mask from second half. </p><p>Those can also be calculated in O(2 ^ 12 * 12^3).</p><p>So precalculation part is O(2 ^ 12 * 12 ^ 3) = 7077888 operations.</p><p>For calculate answering queries complexity, take all numbers from 0 to 2^24 — 1 and sum their bit count. This is a well known problem, the sum is 0 * C(24, 0) + 1 * C(24, 1) + ... + 24 * C(24, 24) = 201326592. In total we get 208404480 operations. C++ source makes them in 2 seconds. </p><p>Code: <a href=\"http://pastie.org/8651829\">http://pastie.org/8651829</a></p><h2>Solution fount by contestants</h2><p>Like in D1 D task, official solution was over complicated. This solution is more simple to understand, code and it's more elegant. If someone wants to complicate his life, (s)he can code also official solution :)</p><p>Let's start by assigning a bitmask to each word in following way: ith bit is 1 if and only if letter ('a' + i) appears in the current word. For example, for word acd, its bitmask is 2^0 + 2^2 + 2 ^ 3 = 13 and for word aab its bitmask is 2^0 + 2^1 = 3. After reading the words from dictionary, we store a matrix cnt[mask] = how many words from dictionary correspond to mask?</p><p>We iterate bitmasks from 0 to 2^24 — 1, this time corresponding to each possible question of Iahubina. Let's focus on a bitmask X. We need to get sum of cnt[mask], when mask and X share at least one common bit having value 1 (formally (X AND mask) > 0). In order to do this, we need a reduction which may be not so obvious. </p><p>What if instead of counting all words containing at least one of vowels {w1, w2, ..., wk} we count all words which don't contain ANY of vowels {w1, w2, ..., wk}? Suppose this number is ret. Then, all words containing at least one of vowels is N — ret. From all words, we erase those words which do not contain any vowels from set {w1, w2, ..., wk} (and which obviously are wrong words). Obviously, it's left only words containing at least one vowel, so good words. Now, for a word not to contain any of vowels {w1, w2, ..., wk} it needs to contains ONLY vowels from set {"a", "b", "c", ..., "x"} \\ {w1, w2, ..., wk} (set of allowed letters from which we erased vowels w1, w2, ..., wk}. </p><p>And this is reduction we needed. For a bitmask X we need to calculate sum of cnt[mask], where mask is a subset of X (we can set some bits from X from 1 to 0 in order to obtain mask). For a mask, let's keep this sum in res[mask]. We can calculate res array using divide and conquer.</p><p>Let's make a function solve(left, right), which completes array res in the way described above, if we consider only elements cnt[k] with left <= k < right (for simplicity, I'll consider elements which do not lie in this range to be equal to 0). Now we need to solve for a range [left, right]. Let's have in res1[] = solve(left, med) and in res2[] = solve(med, right), where med = (left + right) / 2. We need to put together res1[] and res2[] in order to obtain res[].</p><p>for (int i = left; i < med; ++i) res[i] = res1[i];</p><p>Numbers in [left, med] have most significant bit equal to 0. We can only keep it 0 and add what we calculated before. We can't add any element from res2[], because those elements have most significant bit equal to 1 and we're not allowed to change bit 0 into bit 1.</p><p>for (int i = med; i < right; ++i) res[i] = res1[i — med] + res2[i];</p><p>Here, most significant bit is 1. Adding res1[] corresponds to changing bit from 1 to 0, adding res2[] corresponds to leaving bit 1.</p><p>Of course, we need to threat the base case here, too. When left + 1 = right, res[left] = cnt[left]. We can keep only one array res[] instead of 3, I explained it this way only for simplicity. Also, there is no need for keeping separate arrays for res[] and cnt[], one can solve all task with only one array. In order to get res[], we simply call solve(0, 2^24).</p><p>Complexity of solution is O(2 ^ 24 * 24). I leave the proof homework, it's almost identical to complexity proof of D1 D "Author solution" (that with building a binary tree).</p><p>For a reference solution, check <a class=\"rated-user user-red\" href=\"/profile/Endagorion\" title=\"Grandmaster Endagorion\">Endagorion</a>'s AC source during contest. </p></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/384\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 225 (Div. 2)</a> </span>\r\n </div>\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/383\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 225 (Div. 1)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-12457-10531\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"12457\",\n blogEntryId: \"10476\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n <div style=\"font-size: 1.1rem;line-height: 11px;\">\r\n <img style=\"vertical-align: middle;\" src=\"//codeforces.org/s/81027/images/blog/tags.png\" title=\"Tags\" alt=\"Tags\"/>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=codeforces\" class=\"tag notice\" style=\"text-decoration: none;\">codeforces</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=225\" class=\"tag notice\" style=\"text-decoration: none;\">225</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=editorial\" class=\"tag notice\" style=\"text-decoration: none;\">editorial</a>\r\n </span>\r\n </div>\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-10531\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+418</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-10531\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/fchirica\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/fchirica\">\n fchirica\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Jan/20/2014 22:18\">10 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/10476#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/10476#comments\">\n 52\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"10547\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (45)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158582\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PAP\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/78534/avatar/d5bcc04085999f83.jpg'/> </a>\n <div><a href=\"/profile/PAP\" title=\"Candidate Master PAP\" class=\"rated-user user-violet\">PAP</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 22:40\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158582\" href=\"?#comment-158582\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158582\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"32\"\r\n data-commentUserId=\"78534\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+32</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158582\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>perfect editorial! thanks a lot!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158582 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158582 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158582\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158591\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/eduardische\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2320/avatar/3ac70493aa90ad2e.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/eduardische\" title=\"International Master eduardische\" class=\"rated-user user-orange\">eduardische</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 22:48\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158591\" href=\"?#comment-158591\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"158591\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"158591\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"10\"\r\n data-commentUserId=\"2320\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+10</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158591\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Just would like to report a typo in 383D contestants' solution: the formula computes D[i+1][j] and not D[i][j]. Thanks for the quick editorial!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158591 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158591 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158591\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158596\" commentParentId=\"158591\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/fchirica\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/57267/avatar/4e655c69b8ad66c2.jpg'/> </a>\n <div><a href=\"/profile/fchirica\" title=\"Candidate Master fchirica\" class=\"rated-user user-violet\">fchirica</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 22:52\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158596\" href=\"?#comment-158596\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-158591\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158596\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"15\"\r\n data-commentUserId=\"57267\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+15</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158596\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks. Fixed. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158596 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158596 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158596\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158598\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Mikester\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/109566/avatar/401b6d72d8f2e768.jpg'/> </a>\n <div><a href=\"/profile/Mikester\" title=\"Master Mikester\" class=\"rated-user user-orange\">Mikester</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 22:54\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158598\" href=\"?#comment-158598\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158598\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"13\"\r\n data-commentUserId=\"109566\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+13</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158598\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>elfus has some of the best rounds on Codeforces, and definitely the best editorials. Congratulations to you and Rares for the round !</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158598 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158598 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158598\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158599\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/iPs\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/144469/avatar/10358ae72910ceac.jpg'/> </a>\n <div><a href=\"/profile/iPs\" title=\"Expert iPs\" class=\"rated-user user-blue\">iPs</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 22:54\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158599\" href=\"?#comment-158599\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158599\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"33\"\r\n data-commentUserId=\"144469\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+33</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158599\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>best editorial I have ever seen in codeforces</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158599 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158599 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158599\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158600\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/bli0042\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/88584/avatar/51c3a9b55a3537fa.jpg'/> </a>\n <div><a href=\"/profile/bli0042\" title=\"Candidate Master bli0042\" class=\"rated-user user-violet\">bli0042</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 22:54\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158600\" href=\"?#comment-158600\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"158600\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"158600\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"88584\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158600\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For Div 2C, if A[i] = A[j] = 0 and we put i before j, won't j lose milk? Or am I misinterpreting the solution?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158600 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158600 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158600\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158601\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/aabs08\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/aabs08\" title=\"Expert aabs08\" class=\"rated-user user-blue\">aabs08</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 22:55\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158601\" href=\"?#comment-158601\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"158601\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"158601\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"9\"\r\n data-commentUserId=\"86699\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+9</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158601\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>One of the best editorials i came across in codeforces :D otherwise the editorial here are really very short and objective.</p><p>Every one here should write editorials like you :) !!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158601 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158601 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158601\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158607\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Xellos\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/69675/avatar/8526bcfc8e687b43.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/Xellos\" title=\"International Grandmaster Xellos\" class=\"rated-user user-red\">Xellos</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 23:03\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158607\" href=\"?#comment-158607\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"158607\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"158607\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"17\"\r\n data-commentUserId=\"69675\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+17</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158607\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Finally a tutorial worth upvoting!</p><p>I didn't really need to think about D. As soon as I saw the constraint on <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/986936bec272878d92f9c6fb0f0ce3c5b118cc0e.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />, I decided to try a DP on (position,sum) — it was a massive hint for me. Well, sometimes it just happens that there's a simple solution, which the author doesn't realize :D. Maybe this could be eliminated by some extensive "problem testing" by random capable people?</p><p>I guess I was also lucky in not trying to solve B. I solved in the order: A (because it's easy), C (because I like it), D (because it's easy) :D</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158607 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158607 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158607\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158610\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Mostafa_36a2\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/137637/avatar/28a01293a2b409.jpg'/> </a>\n <div><a href=\"/profile/Mostafa_36a2\" title=\"Specialist Mostafa_36a2\" class=\"rated-user user-cyan\">Mostafa_36a2</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 23:09\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158610\" href=\"?#comment-158610\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158610\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"-9\"\r\n data-commentUserId=\"137637\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-9</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158610\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I've found a very short solution for Div2 C , by zxz5759209</p> <pre><code>scanf("%d",&n);\n LL cnt=0,sum=0;\n for(int i=1;i<=n;i++)\n {\n scanf("%d",&x);\n cnt+=(LL)x;\n if(!x)sum+=cnt;\n }\n printf("%I64d\\n",sum);\n</code></pre></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158610 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158610 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158610\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158641\" commentParentId=\"158610\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Robert.One\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Robert.One\" title=\"Pupil Robert.One\" class=\"rated-user user-green\">Robert.One</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 01:27\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158641\" href=\"?#comment-158641\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-158610\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158641\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"150202\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158641\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I also had this solution and i got accepted but it took 1 hour to find it during the contest</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158641 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158641 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158641\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158612\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Darek_\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Darek_\" title=\"Specialist Darek_\" class=\"rated-user user-cyan\">Darek_</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 23:12\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158612\" href=\"?#comment-158612\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158612\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"152123\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158612\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks for an informative editorial.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158612 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158612 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158612\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158618\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Mostafa_36a2\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/137637/avatar/28a01293a2b409.jpg'/> </a>\n <div><a href=\"/profile/Mostafa_36a2\" title=\"Specialist Mostafa_36a2\" class=\"rated-user user-cyan\">Mostafa_36a2</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 23:25\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158618\" href=\"?#comment-158618\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"158618\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"158618\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"137637\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158618\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Unbelivable solution for Div2,B by Sick_Coder</p> <pre><code>cin >> n >> m >> k;\n cout << m * (m - 1) / 2 << "\\n";\n\n for (1, m, i)\n \tfor (i + 1, m, j)\n \t\tif (!k)\n \t\t\tcout << i << " " << j << "\\n";\n \t\telse\t\n \t\t\tcout << j << " " << i << "\\n";\n</code></pre></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158618 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158618 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158618\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158631\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mugurelionut\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/63702/avatar/45e4d5390c215090.jpg'/> </a>\n <div><a href=\"/profile/mugurelionut\" title=\"International Master mugurelionut\" class=\"rated-user user-orange\">mugurelionut</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 23:57\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158631\" href=\"?#comment-158631\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158631\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"63702\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158631\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>A very good editorial, indeed! (but please don't forget about Div1E) And the problems were really nice. But I think problem B was tougher than it should have been for its amount of points. I've read some comments saying that problem B had too weak pretests (because so many solutions failed the final system tests). I would have to say that my experience with problem B was the exact opposite. I coded two wrong solutions (which failed some pretest or another) before eventually finding and implementing the right solution. So I'd say that problem B had good pretests :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158631 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158631 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158631\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158635\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/MohammadFatafta\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/148405/avatar/4276577919b9713d.jpg'/> </a>\n <div><a href=\"/profile/MohammadFatafta\" title=\"Specialist MohammadFatafta\" class=\"rated-user user-cyan\">MohammadFatafta</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 00:11\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158635\" href=\"?#comment-158635\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158635\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"148405\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158635\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>now this is a real editorial!! thanks guys :D</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158635 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158635 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158635\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158636\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/matrix\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/matrix\" title=\"Master matrix\" class=\"rated-user user-orange\">matrix</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 00:15\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158636\" href=\"?#comment-158636\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"158636\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"158636\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"16572\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158636\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Hi,</p><p>Great and fast editorial with complete details. </p><p>Thanks very much.</p><p>Edit: I think there is a small typo: "It’s not hard to see that answer for a fixed (i1, j1) is left[i1][j1] * value[2 * j1 – sum_of_elements_from_i1]." I guess you meant count[2 * j1 – sum_of_elements_from_i1].</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158636 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158636 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158636\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158637\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Kyuubi\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/83590/avatar/b87432a652bb276.jpg'/> </a>\n <div><a href=\"/profile/Kyuubi\" title=\"Expert Kyuubi\" class=\"rated-user user-blue\">Kyuubi</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 00:18\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158637\" href=\"?#comment-158637\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158637\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"2\"\r\n data-commentUserId=\"83590\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+2</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158637\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Best Editorials I have seen on codeforces yet! :D</p><p>For Propagating tree, how do we keep track of alternating levels in the arrays we created using DFS ? </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158637 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158637 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158637\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158640\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/k_____k\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/60285/avatar/422359e1ae9d666c.jpg'/> </a>\n <div><a href=\"/profile/k_____k\" title=\"Expert k_____k\" class=\"rated-user user-blue\">k_____k</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 01:07\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158640\" href=\"?#comment-158640\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158640\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"2\"\r\n data-commentUserId=\"60285\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+2</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158640\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Best Editorials Ever ! #thanks to the authors, for posting alternative solutions of contestants also. Great start in 2014. #Looking Forward.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158640 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158640 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158640\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158658\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/sillycross\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/41652/avatar/58966d0c793c6394.jpg'/> </a>\n <div><a href=\"/profile/sillycross\" title=\"Grandmaster sillycross\" class=\"rated-user user-red\">sillycross</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 07:49\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158658\" href=\"?#comment-158658\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158658\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"9\"\r\n data-commentUserId=\"41652\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+9</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158658\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Div1 E can be solved in O(2^24*24) or O(2^24+2^12*n)..</p><p>O(2^24*24): dp[i][s] means the sum of all contributions of subset s where all digits are same as s except the last i digits.. </p><p>O(2^24+2^12*n): the length of word is only 3. We divide the 24 letters in half, calculate the answer for all first 12 letters and all last 12 letters and merge them with brute-force. This can be solved in O(2^24). Then we subtract the words that are counted twice: these words are words that have 2 letters in first half and 1 in second half, or 2 in second half and 1 in first half. Let's consider the first case: for each subset of first 12 letters we check each word whether it has exactly 2 letters in this half, if so, we can say all masks in another half that contains the third letter need to be subtracted by 1. This can be solved in 2^12*(2^12+n). Same algorithm can be used to solve the second case. Although this algorithm runs slower than O(2^24*24) bcuz of its larger constant... </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158658 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158658 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158658\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158663\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/VeniVidiVici\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/VeniVidiVici\" title=\"Candidate Master VeniVidiVici\" class=\"rated-user user-violet\">VeniVidiVici</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 09:39\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158663\" href=\"?#comment-158663\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158663\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"149163\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158663\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Very nice editorial! Disappointed in Div 2B though, really expected the "real" problem rather than just insertion sort but that's what you get for not reading carefully ;)</p><p>However, does anyone have an accepted solution that is "real" (e.g. finds the minimum number of operations necessary and prints such a solution)? I was close but my computer died during contest and I haven't tried so much since (of course you can do O((mn)^2) easily but this is way too slow, there should be a O(n*m^2) solution but again my computer was unable to operate). My approach was to make 2-D boolean array to check if a swap is necessary, but I'm not sure if order of operations will end up being a big problem.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158663 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158663 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158663\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158685\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/LegendaryGrandmaster\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/142091/avatar/a3a5a4b5c26ac419.jpg'/> </a>\n <div><a href=\"/profile/LegendaryGrandmaster\" title=\"Specialist LegendaryGrandmaster\" class=\"rated-user user-cyan\">LegendaryGrandmaster</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 14:34\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158685\" href=\"?#comment-158685\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158685\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"142091\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158685\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>One of the best codeforces editorials ever! Thanks!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158685 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158685 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158685\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158687\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/BENYAM1N\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/84938/avatar/d2ae2657d8898e38.jpg'/> </a>\n <div><a href=\"/profile/BENYAM1N\" title=\"Master BENYAM1N\" class=\"rated-user user-orange\">BENYAM1N</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 15:24\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158687\" href=\"?#comment-158687\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"158687\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"158687\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"84938\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158687\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks a lot. very good contest and good editorial too!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158687 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158687 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158687\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158689\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/JuanMata\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/82548/avatar/a7d69af7b441c6d7.jpg'/> </a>\n <div><a href=\"/profile/JuanMata\" title=\"Expert JuanMata\" class=\"rated-user user-blue\">JuanMata</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 15:47\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158689\" href=\"?#comment-158689\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158689\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"82548\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158689\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>this is one of the best editorials on CF ever!!!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158689 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158689 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158689\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158700\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Vicfred\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/76941/avatar/d067b7433ec39337.jpg'/> </a>\n <div><a href=\"/profile/Vicfred\" title=\"Pupil Vicfred\" class=\"rated-user user-green\">Vicfred</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 16:25\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158700\" href=\"?#comment-158700\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158700\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"11\"\r\n data-commentUserId=\"76941\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+11</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158700\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>The best editorial I've read in a while here, thanks.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158700 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158700 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158700\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158727\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/beecoder\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/beecoder\" title=\"Pupil beecoder\" class=\"rated-user user-green\">beecoder</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 21:13\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158727\" href=\"?#comment-158727\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158727\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"89551\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158727\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Hi, The way I print answers for 'Coder Problem' is as follows. This takes 124 ms. is there a way to print the answers faster ? </p> <pre><code> \tfor (int i = 0 ; i < number ; i ++ ) { \n \t\tfor (int k = 0 ; k < number ; k ++ ) { \n \t\t\tif (flag) {\n \t\t\t\tif ( k % 2 == 1) out.print('.');\n \t\t\t\tif( k% 2 == 0 ) out.print('C');\n \t\t\t} else {\n \t\t\tif ( k % 2 == 1) out.print('C');\n \t\t\tif( k% 2 == 0 ) out.print('.');\t\n \t\t\t}\n \t\t}\n \t\tif (flag) flag = false;\n \t\telse flag = true;\n \t\tout.print("\\n");\n \t}\n \n</code></pre></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158727 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158727 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158727\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158742\" commentParentId=\"158727\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Mostafa_36a2\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/137637/avatar/28a01293a2b409.jpg'/> </a>\n <div><a href=\"/profile/Mostafa_36a2\" title=\"Specialist Mostafa_36a2\" class=\"rated-user user-cyan\">Mostafa_36a2</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/22/2014 14:00\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158742\" href=\"?#comment-158742\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-158727\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158742\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"137637\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158742\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>As the line contains k characters , and every odd lines are identical , also the even ones,</p><p>you can build 2 strings [C.C.C.C] and [.C.C.C.] and print them alternately </p><p>[In my opinion Java is slow language any way ]</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158742 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158742 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158742\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158752\" commentParentId=\"158727\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/t_thirupathi\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/146179/avatar/98c28348196ce4ca.jpg'/> </a>\n <div><a href=\"/profile/t_thirupathi\" title=\"Specialist t_thirupathi\" class=\"rated-user user-cyan\">t_thirupathi</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/22/2014 18:19\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158752\" href=\"?#comment-158752\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-158727\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158752\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"146179\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158752\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Modulo operations are time consuming.</p><p>To check if a number <code>n</code> is odd, you could use <code>if (n & 1)</code></p> <pre><code>for (int i = 0; i < n; i++) {\n for (int j = 0; j < n; j++)\n if ((i + j) & 1)\n out.print('.');\n else \n out.print('C');\n out.print('\\n');\n}\n</code></pre></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158752 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158752 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158752\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158745\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/JuanMata\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/82548/avatar/a7d69af7b441c6d7.jpg'/> </a>\n <div><a href=\"/profile/JuanMata\" title=\"Expert JuanMata\" class=\"rated-user user-blue\">JuanMata</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/22/2014 14:49\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158745\" href=\"?#comment-158745\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"158745\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"158745\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"82548\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158745\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>i think there is a small bug in the <a href=\"http://pastie.org/8651824\">pastie link</a> u posted for the solution of Div1 C problem.</p><p>i submitted almost exact copy of it (<a href=\"/contest/383/submission/5769615\" title=\"Submission 5769615 by JuanMata\">5769615</a>), but got WA#6. then i found the bug, corrected it and resubmitted (<a href=\"/contest/383/submission/5769890\" title=\"Submission 5769890 by JuanMata\">5769890</a>) and got AC.</p><p>referring to my two submissions, corrections in line <strong>68</strong> (last statement of <strong>dfs</strong>) and line <strong>109</strong> (the second call to <strong>update</strong>).</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158745 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158745 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158745\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"615836\" commentParentId=\"158745\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/adityakr007\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/adityakr007\" title=\"Expert adityakr007\" class=\"rated-user user-blue\">adityakr007</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/05/2020 18:54\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-615836\" href=\"?#comment-615836\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-158745\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"615836\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"866209\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-615836\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can you explain what exactly have you done in your submission (<a href=\"/contest/383/submission/5769890\" title=\"Submission 5769890 by JuanMata\">5769890</a>) for this problem?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-615836 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-615836 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-615836\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"629531\" commentParentId=\"615836\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/JuanMata\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/82548/avatar/a7d69af7b441c6d7.jpg'/> </a>\n <div><a href=\"/profile/JuanMata\" title=\"Expert JuanMata\" class=\"rated-user user-blue\">JuanMata</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/25/2020 18:14\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-629531\" href=\"?#comment-629531\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-615836\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"629531\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"82548\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-629531\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>sorry bro i've forgotten ... that was over 6yrs ago now!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-629531 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-629531 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-629531\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158751\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/TempuX\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/30820/avatar/c50adc243ea4e2fa.jpg'/> </a>\n <div><a href=\"/profile/TempuX\" title=\"Specialist TempuX\" class=\"rated-user user-cyan\">TempuX</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/22/2014 17:07\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158751\" href=\"?#comment-158751\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158751\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"30820\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158751\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Hi, I tried to implement the Volcano problem in the way explained in the editorial but I'm getting TLE. Here is my code <a href=\"//codeforces.com/contest/384/submission/5770818\">submission</a> What am I doing wrong ? Thanks anyway.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158751 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158751 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158751\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158811\" commentParentId=\"158751\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/TempuX\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/30820/avatar/c50adc243ea4e2fa.jpg'/> </a>\n <div><a href=\"/profile/TempuX\" title=\"Specialist TempuX\" class=\"rated-user user-cyan\">TempuX</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/23/2014 17:29\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158811\" href=\"?#comment-158811\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-158751\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158811\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"30820\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158811\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Turns out my binary search is causing the problem and I don't see what is wrong with it... I would appreciate any ideas.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158811 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158811 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158811\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159025\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/bboy_drain\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/76710/avatar/e0feb3aa135911d4.jpg'/> </a>\n <div><a href=\"/profile/bboy_drain\" title=\"Expert bboy_drain\" class=\"rated-user user-blue\">bboy_drain</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/25/2014 01:34\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159025\" href=\"?#comment-159025\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159025\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"76710\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159025\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Wow! This really helped me a lot! Very detailed explanations!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159025 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159025 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159025\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159092\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/AlexandruValeanu\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/131651/avatar/1c7d989c45052941.jpg'/> </a>\n <div><a href=\"/profile/AlexandruValeanu\" title=\"Candidate Master AlexandruValeanu\" class=\"rated-user user-violet\">AlexandruValeanu</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/25/2014 21:27\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159092\" href=\"?#comment-159092\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159092\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"131651\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159092\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>It was by far your best round on Codeforces, <a class=\"rated-user user-blue\" href=\"/profile/fchirica\" title=\"Expert fchirica\">fchirica</a>. The problems were great, very different one from the other and some of them didn't require any algorithmic skills at all. Good job!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159092 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159092 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159092\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159261\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lawsonh\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/lawsonh\" title=\"Expert lawsonh\" class=\"rated-user user-blue\">lawsonh</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/28/2014 06:33\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159261\" href=\"?#comment-159261\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"159261\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"159261\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"55047\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159261\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>for div1 383C should end[5] = 7? edit: nvm drew the tree wrong</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159261 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159261 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159261\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159474\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/tiagonapoli\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/150060/avatar/6615fcab66b23361.jpg'/> </a>\n <div><a href=\"/profile/tiagonapoli\" title=\"Candidate Master tiagonapoli\" class=\"rated-user user-violet\">tiagonapoli</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/30/2014 22:28\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159474\" href=\"?#comment-159474\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159474\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"150060\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159474\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Great Editorial! Thanks so much, i've learned a lot!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159474 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159474 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159474\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159707\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lchf\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/60496/avatar/e9939e755252ec16.jpg'/> </a>\n <div><a href=\"/profile/lchf\" title=\"Candidate Master lchf\" class=\"rated-user user-violet\">lchf</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/02/2014 17:28\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159707\" href=\"?#comment-159707\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159707\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"60496\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159707\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Amazing solution by Endagorion.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159707 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159707 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159707\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"177400\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/sourabh912\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/57335/avatar/bf83b9340e3cbb17.jpg'/> </a>\n <div><a href=\"/profile/sourabh912\" title=\"Specialist sourabh912\" class=\"rated-user user-cyan\">sourabh912</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/12/2014 20:39\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-177400\" href=\"?#comment-177400\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"177400\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"57335\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-177400\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In Div 1C problem, I could not understand how it can be solved using single fenwick tree from the solution link in the editorial. Can anyone please help.</p><p>Thanks</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-177400 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-177400 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-177400\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"291157\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/l_Love_KFC\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/258117/avatar/bbaec3ce1613f5bd.jpg'/> </a>\n <div><a href=\"/profile/l_Love_KFC\" title=\"Expert l_Love_KFC\" class=\"rated-user user-blue\">l_Love_KFC</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Apr/29/2016 08:23\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-291157\" href=\"?#comment-291157\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"291157\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"258117\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-291157\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In Div.1 A I didn't catch the point that in 1st, quote : "If we put i before j, no additional cost will be added. Since j is in right of i and i only adds cost when it finds elements in left of i, j won’t be affected when processing i." Won't we lose milk if we put firstly i, in case of that j sees that and loses milk? Or am I misunderstanding the task? </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-291157 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-291157 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-291157\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"309434\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/haleyk100198\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/416324/avatar/f2d97d505af17e9d.jpg'/> </a>\n <div><a href=\"/profile/haleyk100198\" title=\"Candidate Master haleyk100198\" class=\"rated-user user-violet\">haleyk100198</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/11/2016 06:32\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-309434\" href=\"?#comment-309434\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"309434\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"416324\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-309434\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I wonder how the problem Div1C can be converted to a segment tree lazy propagation implementation question, for trees like (1-2 2-3 3-4 4-5 .... 9999-E4) how can we achieve O(log N) update time?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-309434 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-309434 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-309434\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"310847\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/my_new_handle\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/233736/avatar/24128c61b65e3262.jpg'/> </a>\n <div><a href=\"/profile/my_new_handle\" title=\"Candidate Master my_new_handle\" class=\"rated-user user-violet\">my_new_handle</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/20/2016 14:49\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-310847\" href=\"?#comment-310847\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"310847\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"233736\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-310847\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>а зачем в таске б массив он влияет как-то?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-310847 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-310847 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-310847\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"332763\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/rhezo\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/305605/avatar/aa59e9c2ec688c6a.jpg'/> </a>\n <div><a href=\"/profile/rhezo\" title=\"Candidate Master rhezo\" class=\"rated-user user-violet\">rhezo</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Dec/24/2016 07:56\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-332763\" href=\"?#comment-332763\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"332763\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"305605\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-332763\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I'm getting Runtime Error on test 44 in <a href=\"//codeforces.com/problemset/problem/383/C\">Propogating Tree</a>. </p><p>This is because of stack overflow right? That test has N = 2e5 and for a straight chain of nodes, I'll get a runtime error with a recursive DFS right? What to do in such cases? </p><p>I can write an iterative DFS, but I do HLD recursively too and I'm not quite sure if I can write an iterative HLD. </p><p>Can anyone tell me what to do in such cases? I'm assuming that I got the runtime error due to stackoverflow from DFS.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-332763 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-332763 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-332763\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"346070\" commentParentId=\"332763\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/yinanzhu\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/520731/avatar/d61a58bf5df54146.jpg'/> </a>\n <div><a href=\"/profile/yinanzhu\" title=\"Expert yinanzhu\" class=\"rated-user user-blue\">yinanzhu</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/26/2017 07:18\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-346070\" href=\"?#comment-346070\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-332763\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"346070\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"520731\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-346070\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I used recursive dfs and passed all test case. Test 44 cost 1.5 s</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-346070 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-346070 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-346070\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"387028\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/blue__legend\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/blue__legend\" title=\"Expert blue__legend\" class=\"rated-user user-blue\">blue__legend</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/23/2017 07:16\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-387028\" href=\"?#comment-387028\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"387028\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"284949\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-387028\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>How to solve DIV 1 C using one fenwick or segment tree. The code link given in editorial is not working.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-387028 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-387028 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-387028\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"757423\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Ausmosian\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Ausmosian\" title=\"Expert Ausmosian\" class=\"rated-user user-blue\">Ausmosian</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/05/2021 15:05\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-757423\" href=\"?#comment-757423\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"757423\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"727283\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-757423\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>[<a href=\"https://codeforces.com/contest/383/problem/C\">384E — Propagating tree</a>] Can also be solved using Square Root Decomposition. <a href=\"https://codeforces.com/contest/383/submission/106526543\">Submission</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-757423 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-757423 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-757423\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"838255\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/3hill\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1621900/avatar/478297db63bad207.jpg'/> </a>\n <div><a href=\"/profile/3hill\" title=\"Expert 3hill\" class=\"rated-user user-blue\">3hill</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/11/2021 17:02\">2 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-838255\" href=\"?#comment-838255\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"838255\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1621900\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-838255\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I am Getting MLE on TC-53<br />Can someone review my code and figure out the issue ,Thanks</p> <ul> <li><a href=\"https://codeforces.com/contest/383/problem/C\">Problem</a></li> <li><a href=\"https://codeforces.com/contest/383/submission/128510633\">My code</a></li> </ul></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-838255 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-838255 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-838255\">\r\n </ul>\r\n</div>\r\n <br/>\r\n\r\n<div id=\"editBox-10547\" style=\"width:50em;display:none;\">\r\n <div class=\"previewBody\" style=\"border: 1px solid #d4d4d4; margin-bottom: 0.5em; padding: 0.25em; display:none;\"> </div>\r\n <div style=\"width: 1px\"> </div>\r\n <div class=\"commentLocale\" style=\"position: relative; top: 0.5em;left:4px;display: none;\">\r\n <input type=\"radio\" name=\"locale\" value=\"en\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In English</span>\r\n <input style=\"margin-left:1em\" type=\"radio\" name=\"locale\" value=\"ru\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In Russian</span>\r\n </div>\r\n <textarea data-drafts-id=\"CommentReplyFrame\" class=\"wysiwyg\" name=\"editContent\" rows=\"20\" style=\"width:99%;\"></textarea>\r\n <div class=\"error error__content\"></div>\r\n <div style=\"text-align:center;\">\r\n <input type=\"button\" name=\"preview\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Preview\"/>\r\n <input type=\"button\" name=\"save\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Save\"/>\r\n </div>\r\n</div>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n\r\nvar firstPreview10547 = true;\r\nvar lastPreviewContent10547 = '';\r\n\r\nif (!window.moveCommentRevision) {\r\n moveCommentRevision = function(e, dir) {\r\n var p = e.parent();\r\n var revisionCount = parseInt(p.attr(\"revisionCount\"));\r\n var revision = parseInt(p.attr(\"revision\"));\r\n var next = revision + dir;\r\n var commentId = p.attr(\"commentId\");\r\n if (next >= 1 && next <= revisionCount) {\r\n $.post(\r\n \"/data/comment-data\",\r\n {action: \"revision\", commentId: commentId, revision: next},\r\n function(json) {\r\n if (json.success == \"true\") {\r\n var parentDiv = e;\r\n\r\n while (parentDiv !== null && (parentDiv[0].nodeName.toLowerCase() !== \"td\" || !parentDiv.hasClass(\"right\"))) {\r\n parentDiv = parentDiv.parent();\r\n }\r\n\r\n if (parentDiv === null) {\r\n return;\r\n }\r\n\r\n parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\").html(json.content);\r\n Codeforces.setupSpoilers(parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\"));\r\n p.attr(\"revision\", next);\r\n p.find(\"span.revision\").text(next);\r\n if (next == 1) {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"visible\");\r\n }\r\n if (next == revisionCount) {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"visible\");\r\n }\r\n\r\n window.updateTypography();\r\n MathJax.Hub.Typeset();\r\n } else {\r\n alert(e.error);\r\n }\r\n },\r\n \"json\"\r\n );\r\n }\r\n };\r\n}\r\n\r\n$(\"div[commentableId=10547] a.leftRevision\").click(function () {\r\n window.moveCommentRevision($(this), -1);\r\n return false;\r\n});\r\n\r\n$(\"div[commentableId=10547] a.rightRevision\").click(function () {\r\n window.moveCommentRevision($(this), +1);\r\n return false;\r\n});\r\n\r\n\r\n\r\n });\n </script>\n\r\n\r\n <script src=\"//codeforces.org/s/81027/js/swfobject-2.2.min.js\" type=\"text/javascript\"></script>\n <script src=\"//codeforces.org/s/81027/js/ftaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n if (window.evercookie) {\n var ec = new evercookie({\n history: false,\n silverlight: false,\n baseurl: '',\n asseturi: '/assets',\n phpuri: '/2fdcd78',\n pngPath: '/eps',\n etagPath: '/ees',\n cachePath: '/ecs'\n });\n\n var randomNumber = function () {\n return Math.random().toString(36).substr(2);\n };\n\n var randomToken = function () {\n return (randomNumber() + randomNumber()).substring(0, 18);\n };\n\n window._ftaa = \"\";\n\n ec.get(\"70a7c28f3de\", function (value) {\n window._ftaa = value;\n if (!window._ftaa) {\n window._ftaa = randomToken();\n ec.set(\"70a7c28f3de\", window._ftaa);\n }\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n } else {\n window._ftaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\n <script src=\"//codeforces.org/s/81027/js/bfaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n var fpCallback = function() {\n Fingerprint2.get({}, function(components) {\n window._bfaa = Fingerprint2.x64hash128(components.map(function (pair) { return pair.value }).join(), 31);\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n };\n if (typeof Fingerprint2 !== 'undefined') {\n if (window.requestIdleCallback) {\n requestIdleCallback(fpCallback)\n } else {\n setTimeout(fpCallback, 500)\n }\n } else {\n window._bfaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"a.new-root-comment\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n\r\n $(\".comment-table .reply a\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".vote-for-comment\").mouseover(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").mouseout(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").click(function () {\r\n var vote = $(this);\r\n var commentId = $(this).parent().attr(\"commentid\");\r\n var commentRating = $(this).parent().attr(\"data-commentRating\");\r\n var direction = $(this).attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n $.post(\"/data/comment/vote\", {commentId: commentId, _tta: Codeforces.tta(), vote: direction, commentRating: commentRating}, function(data) {\r\n if (direction != 0 && !ownComment && data[\"success\"] == \"true\") {\r\n vote.parent().find(\".vote-for-comment\").attr(\"voteDirection\", 0);\r\n if (direction == 1)\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n else {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.closest(\".CommentVoteFrame\").find(\".ComplaintFrame\").css(\"display\", \"inline-block\");\r\n }\r\n vote.find(\"img\").attr(\"popacity\", \"1.0\");\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n vote.parent().find(\".commentRating\").html(data[\"commentRating\"]);\r\n }\r\n Codeforces.showMessage(data[\"message\"]);\r\n }, \"json\");\r\n return false;\r\n });\r\n\r\n $(\".negative-comment-vote\").closest(\".comment-table\").addClass(\"comment-bad\");\r\n\r\n $(\".troll-comment-vote\").closest(\".comment\").css(\"display\", \"none\");\r\n\r\n $(\".too-negative-comment-vote\").closest(\".comment-table\").each(function () {\r\n var e = $(this);\r\n e.addClass(\"comment-too-bad\");\r\n var commentId = e.attr(\"commentId\");\r\n $(\"<div class='bad-comment-replacement ttypography'>The comment is hidden because of too negative feedback, click <a href=# class=show-bad-comment-link>here</a> to view it</div>\").appendTo(\r\n e.find(\".right\")\r\n );\r\n e.find(\".comment-content\").hide();\r\n e.find(\".show-bad-comment-link\").click(function () {\r\n e.find(\".comment-content\").show();\r\n e.find(\".bad-comment-replacement\").hide();\r\n return false;\r\n });\r\n });\r\n });\n </script>\n </div>\r\n\r\n <style type=\"text/css\">\r\n .new-comments-box {\r\n padding: 0.5em;\r\n width: 22px;\r\n font-size: 1.3rem;\r\n font-weight: bold !important;\r\n\r\n position: fixed;\r\n top: 40%;\r\n right: 0;\r\n opacity: 0.2;\r\n color: white;\r\n text-align: center;\r\n\r\n border: 1px solid #222;\r\n background-color: #888 !important;\r\n border-radius: 3px;\r\n -moz-border-radius: 3px;\r\n -webkit-border-radius: 3px;\r\n }\r\n\r\n .new-comments-box:hover {\r\n opacity: 1;\r\n }\r\n\r\n .new-comments-box .dir:hover {\r\n background: #3B5998 !important;\r\n cursor: pointer;\r\n }\r\n </style>\r\n\r\n <div class=\"new-comments-box\" data-position=\"outside\" data-index=\"-1\" style=\"display: none;\">\r\n <div class=\"up dir\" title=\"Ctrl+Up\">↑<hr/>\r\n </div>\r\n <div class=\"info\" title=\"New comments\"></div>\r\n <div class=\"down dir\" title=\"Ctrl+Down\">\r\n <hr/>↓\r\n </div>\r\n </div>\r\n\r\n <script>\r\n $(\".show-archived-checkbox\").change(function () {\r\n const checked = $(this).is(\":checked\");\r\n $.post(\"/data/comment-data\", {action: \"setShowArchived\", checked}, function (json) {\r\n if (json[\"success\"] !== \"true\") {\r\n alert(json[\"error\"]);\r\n } else {\r\n if (checked) {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are now displayed\")\r\n } else {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are no longer displayed\")\r\n }\r\n }\r\n });\r\n return false;\r\n });\r\n\r\n function gotoComment(direction) {\r\n var box = $(\".new-comments-box\");\r\n var index = parseInt(box.attr(\"data-index\"));\r\n if (index == -1)\r\n index = 0;\r\n else\r\n index = Math.max(0, Math.min(parseInt(box.find(\".info\").text()) - 1, index + direction));\r\n box.attr(\"data-index\", index);\r\n var comment = $($(\".comment .highlight-blue[commentId]\").get(index));\r\n $('html, body').animate({\r\n 'scrollTop': Math.max(0, comment.offset().top - ($(window).height() - comment.height()) / 2)\r\n });\r\n return false;\r\n }\r\n\r\n $(\".new-comments-box .down\").click(function () {\r\n return gotoComment(1);\r\n });\r\n\r\n $(\".new-comments-box .up\").click(function () {\r\n return gotoComment(-1);\r\n });\r\n\r\n $(document).keydown(function (e) {\r\n var code = (e.keyCode ? e.keyCode : e.which);\r\n if (e.ctrlKey) {\r\n if (code == 38 || code == 40) {\r\n gotoComment(code - 39);\r\n }\r\n }\r\n });\r\n\r\n var newCommentCount = $(\".comment .highlight-blue[commentId]\").length;\r\n if (newCommentCount > 0) {\r\n $(\".new-comments-box .info\").text(newCommentCount);\r\n $(\".new-comments-box\").show();\r\n }\r\n\r\n $('table.comment-table').mouseenter(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").addClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n\r\n $('table.comment-table').mouseleave(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").removeClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n </script>\r\n\r\n\r\n\r\n <script>\r\n function adjustTopicComplainFrames() {\r\n let topicIds = [];\r\n\r\n $(\".has-topic-id\").each(function () {\r\n const $this = $(this);\r\n const topicId = $this.attr(\"topicId\");\r\n if (topicId) {\r\n topicIds.push(topicId);\r\n }\r\n });\r\n\r\n $.post(\"/data/topics\", {\r\n action: \"findComplainableTopicIds\",\r\n topicIds: topicIds.join(\",\")\r\n }, function (json) {\r\n if (json[\"success\"] === \"true\") {\r\n for (const topicId of json[\"complainableTopicIds\"].split(\",\")) {\r\n $(\".has-topic-id[topicId=\" + topicId + \"]\").each(function () {\r\n $(this).find(\".meta .ComplaintFrame\").css(\"display\", \"inline-block\");\r\n });\r\n }\r\n }\r\n }, \"json\");\r\n }\r\n\r\n $(function () {\r\n adjustTopicComplainFrames();\r\n })\r\n </script>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-10531\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 10531, _tta: Codeforces.tta(), topicRevisionId: 36233, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-10531\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 10531, _tta: Codeforces.tta(), topicRevisionId: 36233, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n </div>\r\n </div>\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 22:13:02</span> (h1).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/81027/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/81027/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/81027/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/81027/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-81027.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'81287584a8369d92',t:'MTY5NjcwNTk4Mi42NDcwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"}}},{"rowIdx":1940,"cells":{"problem_id":{"kind":"string","value":"384B"},"contest":{"kind":"string","value":"384"},"problem":{"kind":"string","value":"B"},"lang":{"kind":"string","value":"en"},"problem_title":{"kind":"string","value":"B. Multitasking"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">B. Multitasking</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Iahub wants to enhance his multitasking abilities. In order to do this, he wants to sort <span class=\"tex-span\"><i>n</i></span> arrays simultaneously, each array consisting of <span class=\"tex-span\"><i>m</i></span> integers.</p><p>Iahub can choose a pair of distinct indices <span class=\"tex-span\"><i>i</i></span> and <span class=\"tex-span\"><i>j</i></span> <span class=\"tex-span\">(1 ≤ <i>i</i>, <i>j</i> ≤ <i>m</i>, <i>i</i> ≠ <i>j</i>)</span>. Then in each array the values at positions <span class=\"tex-span\"><i>i</i></span> and <span class=\"tex-span\"><i>j</i></span> are swapped only if the value at position <span class=\"tex-span\"><i>i</i></span> is strictly greater than the value at position <span class=\"tex-span\"><i>j</i></span>.</p><p>Iahub wants to find an array of pairs of distinct indices that, chosen in order, sort all of the <span class=\"tex-span\"><i>n</i></span> arrays in ascending or descending order (the particular order is given in input). The size of the array can be at most <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/6f1b5d2dbdd1c5069f06964cc691c24429c6151c.png\" style=\"max-width: 100.0%;max-height: 100.0%;\"/> (at most <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/6f1b5d2dbdd1c5069f06964cc691c24429c6151c.png\" style=\"max-width: 100.0%;max-height: 100.0%;\"/> pairs). Help Iahub, find any suitable array.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains three integers <span class=\"tex-span\"><i>n</i></span> <span class=\"tex-span\">(1 ≤ <i>n</i> ≤ 1000)</span>, <span class=\"tex-span\"><i>m</i></span> <span class=\"tex-span\">(1 ≤ <i>m</i> ≤ 100)</span> and <span class=\"tex-span\"><i>k</i></span>. Integer <span class=\"tex-span\"><i>k</i></span> is <span class=\"tex-span\">0</span> if the arrays must be sorted in ascending order, and <span class=\"tex-span\">1</span> if the arrays must be sorted in descending order. Each line <span class=\"tex-span\"><i>i</i></span> of the next <span class=\"tex-span\"><i>n</i></span> lines contains <span class=\"tex-span\"><i>m</i></span> integers separated by a space, representing the <span class=\"tex-span\"><i>i</i></span>-th array. For each element <span class=\"tex-span\"><i>x</i></span> of the array <span class=\"tex-span\"><i>i</i></span>, <span class=\"tex-span\">1 ≤ <i>x</i> ≤ 10<sup class=\"upper-index\">6</sup></span> holds.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>On the first line of the output print an integer <span class=\"tex-span\"><i>p</i></span>, the size of the array (<span class=\"tex-span\"><i>p</i></span> can be at most <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/6f1b5d2dbdd1c5069f06964cc691c24429c6151c.png\" style=\"max-width: 100.0%;max-height: 100.0%;\"/>). Each of the next <span class=\"tex-span\"><i>p</i></span> lines must contain two distinct integers <span class=\"tex-span\"><i>i</i></span> and <span class=\"tex-span\"><i>j</i></span> <span class=\"tex-span\">(1 ≤ <i>i</i>, <i>j</i> ≤ <i>m</i>, <i>i</i> ≠ <i>j</i>)</span>, representing the chosen indices.</p><p>If there are multiple correct answers, you can print any.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>2 5 0<br/>1 3 2 5 4<br/>1 4 3 2 5<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>3<br/>2 4<br/>2 3<br/>4 5<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3 2 1<br/>1 2<br/>2 3<br/>3 4<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1<br/>2 1<br/></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>Consider the first sample. After the first operation, the arrays become <span class=\"tex-span\">[1, 3, 2, 5, 4]</span> and <span class=\"tex-span\">[1, 2, 3, 4, 5]</span>. After the second operation, the arrays become <span class=\"tex-span\">[1, 2, 3, 5, 4]</span> and <span class=\"tex-span\">[1, 2, 3, 4, 5]</span>. After the third operation they become <span class=\"tex-span\">[1, 2, 3, 4, 5]</span> and <span class=\"tex-span\">[1, 2, 3, 4, 5]</span>.</p></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"597a6dc3ad657534534efedec5d6fd4a\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - B - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"2080925ccc752dc6d7cc9e06390b1986ca0eae39\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - B - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/73366/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/73366/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/73366/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/73366/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/73366/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/73366/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/73366/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/73366/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/73366/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/73366/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/73366/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/73366/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/73366/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/73366/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/sidebar-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/a037fe51637846d9c7c725713cd840ea/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='597a6dc3ad657534534efedec5d6fd4a'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/73366/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/73366/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fcontest%2F384%2Fproblem%2FB%3Flocale%3Den\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"current\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='597a6dc3ad657534534efedec5d6fd4a'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:100%;\"><a style=\"color: black\" href=\"/contest/384\">Codeforces Round 225 (Div. 2)</a></th>\n </tr>\n <tr>\n <td class=\"left bottom\" colspan=\"1\"><span class=\"contest-state-phase\">Finished</span></td>\n </tr>\n </tbody>\n </table>\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Practice?\n <div class=\"top-links\">\n </div>\n </div>\n<div>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Want to solve the contest problems after the official contest ends? Just register for practice and you will be able to submit solutions.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"\" method=\"post\"><input type='hidden' name='csrf_token' value='597a6dc3ad657534534efedec5d6fd4a'/>\r\n <input type=\"hidden\" name=\"action\" value=\"registerForPractice\"/>\r\n <input type=\"submit\" name=\"submit\" value=\"Register for practice\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div> \r\n</div>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox ContestVirtualFrame borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Virtual participation <i class=\"sidebar-caption-icon las la-angle-down\"></i>\r\n\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\" \"\r\n\r\n data-page-url=\"/data/sidebarFrames\"\r\n\r\n>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests.\n\nIf you've seen these problems, a virtual contest is not for you - solve these problems in the archive.\n\nIf you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.\n\nNever use someone else's code, read the tutorials or communicate with other person during a virtual contest.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"/contest/384/virtual\" method=\"get\">\r\n <input type=\"submit\" name=\"submit\" value=\"Start virtual contest\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div>\r\n</div>\r\n <script>\r\n $(function () {\r\n $(\".ContestVirtualFrame .sidebar-caption-icon\").click(function() {\r\n $(this).toggleClass(\"la-angle-down la-angle-right\");\r\n const $target = $(this).parent().next();\r\n $target.toggle();\r\n const dataPageUrl = $target.attr(\"data-page-url\");\r\n const collapsed = $(this).hasClass(\"la-angle-right\");\r\n const params = {\r\n action: \"setCollapsed\",\r\n sidebarFrameSimpleClassName: \"ContestVirtualFrame\",\r\n collapsed\r\n };\r\n $.each($target[0].attributes, function(i, a) {\r\n const name = a.name;\r\n if (name.startsWith(\"data-extra-key-\")) {\r\n const key = a.value;\r\n const keyIndex = parseInt(name.substring(\"data-extra-key-\".length));\r\n const value = $target.attr(\"data-extra-value-\" + keyIndex);\r\n params[key] = value;\r\n }\r\n });\r\n $.post(dataPageUrl, params, function (result) {\r\n if (result[\"success\"] !== \"true\") {\r\n Codeforces.showMessage(\"Failed to save collapsed state.\");\r\n }\r\n }, \"json\");\r\n return false;\r\n });\r\n })\r\n </script>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Problem tags\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Greedy algorithms\">\r\n greedy\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Implementation problems, programming technics, simulation\">\r\n implementation\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Sortings, orderings\">\r\n sortings\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Two pointers\">\r\n two pointers\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Difficulty\">\r\n *1500\r\n</span>\r\n </div>\n <div style=\"clear:both;text-align:right;font-size:1.1rem;\">\r\n <span title=\"Please login into the Codeforces\" class=\"notice\">No tag edit access</span>\r\n </div>\r\n</div>\r\n </div>\n\r\n<form id=\"addTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='597a6dc3ad657534534efedec5d6fd4a'/>\r\n <input name=\"action\" type=\"hidden\" value=\"addTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"5718\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<form id=\"removeTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='597a6dc3ad657534534efedec5d6fd4a'/>\r\n <input name=\"action\" type=\"hidden\" value=\"removeTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"5718\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<script type=\"text/javascript\">\r\n $(\".tag-box img\").click(function () {\r\n var tagName = $(this).attr(\"value\");\r\n Codeforces.confirm(\"Are you sure you want to remove this tag?\", function () {\r\n $(\"#removeTagForm input[name=tagName]\").val(tagName);\r\n $(\"#removeTagForm\").submit();\r\n }, function () {\r\n }, \"Yes\", \"No\");\r\n });\r\n\r\n $(\"#addTagLink\").click(function () {\r\n $(this).hide();\r\n $(\"#addTagLabel\").show();\r\n return false;\r\n });\r\n\r\n $(\"#addTagSelect\").change(function () {\r\n var tagName = $(this).val();\r\n if (tagName === \"\") {\r\n $(\"#addTagLabel\").hide();\r\n $(\"#addTagLink\").show();\r\n } else {\r\n $(\"#addTagForm input[name=tagName]\").val(tagName);\r\n $(\"#addTagForm\").submit();\r\n }\r\n });\r\n</script>\r\n\r\n<style type=\"text/css\">\r\n#new-resource-form tr td {\r\npadding-top: 0.5em;\r\n}\r\n#new-resource-form input:not([type=\"submit\"]) {\r\nfont-size: 0.8em;\r\n}\r\n#new-resource-form select {\r\nfont-size: 0.8em;\r\n}\r\n.new-resource-error {\r\nfont-size: 0.8em;\r\n}\r\n.resource-locale {\r\ncolor: #666;\r\nfont-family: Consolas, \"Andale Mono WT\", \"Andale Mono\", \"Lucida Console\", \"Lucida Sans Typewriter\", \"DejaVu Sans Mono\", \"Bitstream Vera Sans Mono\", \"Liberation Mono\", \"Nimbus Mono L\", Monaco, \"Courier New\", Courier, monospace;\r\n}\r\n</style>\r\n<div class=\"roundbox sidebox sidebar-menu borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Contest materials\n<div class=\"top-links\">\n</div>\n</div>\n<ul>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/10448\" title=\"Codeforces Round #225\" target=\"_blank\">Codeforces Round #225</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"2168:2169\" resourceName=\"Announcement\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/10476\" title=\"Codeforces Round #225 — Editorial\" target=\"_blank\">Tutorial <span class=\"resource-locale\">(en)</span></a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"2173\" resourceName=\"Codeforces Round #225 — Editorial\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n</ul>\r\n</div></div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li class=\"current selectedLava\"><a\r\n href=\"/contest/384\">Problems</a></li>\r\n <li><a\r\n href=\"/contest/384/submit\">Submit Code</a></li>\r\n <li><a\r\n href=\"/contest/384/my\">My Submissions</a></li>\r\n <li><a\r\n href=\"/contest/384/status\">Status</a></li>\r\n <li><a\r\n href=\"/contest/384/hacks\">Hacks</a></li>\r\n <li><a\r\n href=\"/contest/384/room/1\">Room</a></li>\r\n <li><a\r\n href=\"/contest/384/standings\">Standings</a></li>\r\n <li><a\r\n href=\"/contest/384/customtest\">Custom Invocation</a></li>\r\n</ul>\r\n</div>\n\r\n <style>\r\n #facebox .content:has(.diff-popup) {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n }\r\n\r\n .testCaseMarker {\r\n position: absolute;\r\n font-weight: bold;\r\n font-size: 1rem;\r\n }\r\n\r\n .diff-popup {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n display: none;\r\n overflow: auto;\r\n }\r\n\r\n .input-output-copier {\r\n font-size: 1.2rem;\r\n float: right;\r\n color: #888 !important;\r\n cursor: pointer;\r\n border: 1px solid rgb(185, 185, 185);\r\n padding: 3px;\r\n margin: 1px;\r\n line-height: 1.1rem;\r\n text-transform: none;\r\n }\r\n\r\n .input-output-copier:hover {\r\n background-color: #def;\r\n }\r\n\r\n .test-explanation textarea {\r\n width: 100%;\r\n height: 1.5em;\r\n }\r\n\r\n .pending-submission-message {\r\n color: darkorange !important;\r\n }\r\n </style>\r\n <script>\r\n const OPENING_SPACE = String.fromCharCode(1001);\r\n const CLOSING_SPACE = String.fromCharCode(1002);\r\n\r\n const nodeToText = function (node, pre) {\r\n let result = [];\r\n\r\n if (node.tagName === \"SCRIPT\" || node.tagName === \"math\"\r\n || (node.classList && node.classList.contains(\"input-output-copier\")))\r\n return [];\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(OPENING_SPACE);\r\n }\r\n\r\n if (node.nodeType === Node.TEXT_NODE) {\r\n let s = node.textContent;\r\n if (!pre) {\r\n s = s.replace(/\\s+/g, \" \");\r\n }\r\n if (s.length > 0) {\r\n result.push(s);\r\n }\r\n }\r\n\r\n if (pre && node.tagName === \"BR\") {\r\n result.push(\"\\n\");\r\n }\r\n\r\n node.childNodes.forEach(function (child) {\r\n result.push(nodeToText(child, node.tagName === \"PRE\").join(\"\"));\r\n });\r\n\r\n if (node.tagName === \"DIV\"\r\n || node.tagName === \"P\"\r\n || node.tagName === \"PRE\"\r\n || node.tagName === \"UL\"\r\n || node.tagName === \"LI\"\r\n ) {\r\n result.push(\"\\n\");\r\n }\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(CLOSING_SPACE);\r\n }\r\n\r\n return result;\r\n }\r\n\r\n const isSpecial = function (c) {\r\n return c === ',' || c === '.' || c === ';' || c === ')' || c === ' ';\r\n }\r\n\r\n const convertStatementToText = function(statmentNode) {\r\n const text = nodeToText(statmentNode, false).join(\"\").replace(/ +/g, \" \").replace(/\\n\\n+/g, \"\\n\\n\");\r\n let result = [];\r\n for (let i = 0; i < text.length; i++) {\r\n const c = text.charAt(i);\r\n if (c === OPENING_SPACE) {\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"B\" data-uuid=\"ps_249090ec44519190f3a270c0c943528dc8670b81\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">B. Multitasking</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Iahub wants to enhance his multitasking abilities. In order to do this, he wants to sort <span class=\"tex-span\"><i>n</i></span> arrays simultaneously, each array consisting of <span class=\"tex-span\"><i>m</i></span> integers.</p><p>Iahub can choose a pair of distinct indices <span class=\"tex-span\"><i>i</i></span> and <span class=\"tex-span\"><i>j</i></span> <span class=\"tex-span\">(1 ≤ <i>i</i>, <i>j</i> ≤ <i>m</i>, <i>i</i> ≠ <i>j</i>)</span>. Then in each array the values at positions <span class=\"tex-span\"><i>i</i></span> and <span class=\"tex-span\"><i>j</i></span> are swapped only if the value at position <span class=\"tex-span\"><i>i</i></span> is strictly greater than the value at position <span class=\"tex-span\"><i>j</i></span>.</p><p>Iahub wants to find an array of pairs of distinct indices that, chosen in order, sort all of the <span class=\"tex-span\"><i>n</i></span> arrays in ascending or descending order (the particular order is given in input). The size of the array can be at most <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/6f1b5d2dbdd1c5069f06964cc691c24429c6151c.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> (at most <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/6f1b5d2dbdd1c5069f06964cc691c24429c6151c.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> pairs). Help Iahub, find any suitable array.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains three integers <span class=\"tex-span\"><i>n</i></span> <span class=\"tex-span\">(1 ≤ <i>n</i> ≤ 1000)</span>, <span class=\"tex-span\"><i>m</i></span> <span class=\"tex-span\">(1 ≤ <i>m</i> ≤ 100)</span> and <span class=\"tex-span\"><i>k</i></span>. Integer <span class=\"tex-span\"><i>k</i></span> is <span class=\"tex-span\">0</span> if the arrays must be sorted in ascending order, and <span class=\"tex-span\">1</span> if the arrays must be sorted in descending order. Each line <span class=\"tex-span\"><i>i</i></span> of the next <span class=\"tex-span\"><i>n</i></span> lines contains <span class=\"tex-span\"><i>m</i></span> integers separated by a space, representing the <span class=\"tex-span\"><i>i</i></span>-th array. For each element <span class=\"tex-span\"><i>x</i></span> of the array <span class=\"tex-span\"><i>i</i></span>, <span class=\"tex-span\">1 ≤ <i>x</i> ≤ 10<sup class=\"upper-index\">6</sup></span> holds.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>On the first line of the output print an integer <span class=\"tex-span\"><i>p</i></span>, the size of the array (<span class=\"tex-span\"><i>p</i></span> can be at most <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/6f1b5d2dbdd1c5069f06964cc691c24429c6151c.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />). Each of the next <span class=\"tex-span\"><i>p</i></span> lines must contain two distinct integers <span class=\"tex-span\"><i>i</i></span> and <span class=\"tex-span\"><i>j</i></span> <span class=\"tex-span\">(1 ≤ <i>i</i>, <i>j</i> ≤ <i>m</i>, <i>i</i> ≠ <i>j</i>)</span>, representing the chosen indices.</p><p>If there are multiple correct answers, you can print any.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>2 5 0<br />1 3 2 5 4<br />1 4 3 2 5<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>3<br />2 4<br />2 3<br />4 5<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3 2 1<br />1 2<br />2 3<br />3 4<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1<br />2 1<br /></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>Consider the first sample. After the first operation, the arrays become <span class=\"tex-span\">[1, 3, 2, 5, 4]</span> and <span class=\"tex-span\">[1, 2, 3, 4, 5]</span>. After the second operation, the arrays become <span class=\"tex-span\">[1, 2, 3, 5, 4]</span> and <span class=\"tex-span\">[1, 2, 3, 4, 5]</span>. After the third operation they become <span class=\"tex-span\">[1, 2, 3, 4, 5]</span> and <span class=\"tex-span\">[1, 2, 3, 4, 5]</span>.</p></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=B]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== statementText) {\r\n $problem.find(\".diff-notifier\").show();\r\n\r\n $problem.find(\".diff-notifier-close\").click(function() {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n $problem.find(\".diff-notifier\").hide();\r\n });\r\n\r\n $problem.find(\"a.view-changes\").click(function() {\r\n $.post(\"/data/diff\", {action: \"getDiff\", a: previousStatementText, b: statementText}, function (result) {\r\n if (result[\"success\"] === \"true\") {\r\n Codeforces.facebox(\".diff-popup\", \"//codeforces.org/s/73366\");\r\n $(\"#facebox .diff-popup\").html(result[\"diff\"]);\r\n }\r\n }, \"json\");\r\n });\r\n }\r\n } else {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n }\r\n });\r\n });\r\n </script>\r\n\r\n\r\n<script type=\"text/javascript\">\r\n $(document).ready(function () {\r\n window.changedTests = new Set();\r\n\r\n function endsWith(string, suffix) {\r\n return string.indexOf(suffix, string.length - suffix.length) !== -1;\r\n }\r\n\r\n const inputFileDiv = $(\"div.input-file\");\r\n const inputFile = inputFileDiv.text();\r\n const outputFileDiv = $(\"div.output-file\");\r\n const outputFile = outputFileDiv.text();\r\n\r\n\r\n if (!endsWith(inputFile, \"standard input\")\r\n && !endsWith(inputFile, \"standard input\")) {\r\n inputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n if (!endsWith(outputFile, \"standard output\")\r\n && !endsWith(outputFile, \"standard output\")) {\r\n outputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n const titleDiv = $(\"div.header div.title\");\r\n\r\n\r\n\r\n String.prototype.replaceAll = function (search, replace) {\r\n return this.split(search).join(replace);\r\n };\r\n\r\n $(\".sample-test .title\").each(function () {\r\n const preId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n const cpyId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n\r\n $(this).parent().find(\"pre\").attr(\"id\", preId);\r\n const $copy = $(\"<div title='Copy' data-clipboard-target='#\" + preId + \"' id='\" + cpyId + \"' class='input-output-copier'>Copy</div>\");\r\n $(this).append($copy);\r\n\r\n const clipboard = new Clipboard('#' + cpyId, {\r\n text: function (trigger) {\r\n const pre = document.querySelector('#' + preId);\r\n const lines = pre.querySelectorAll(\".test-example-line\");\r\n return Codeforces.filterClipboardText(pre.innerText, lines.length);\r\n }\r\n });\r\n\r\n const isInput = $(this).parent().hasClass(\"input\");\r\n\r\n clipboard.on('success', function (e) {\r\n if (isInput) {\r\n Codeforces.showMessage(\"The example input has been copied into the clipboard\");\r\n } else {\r\n Codeforces.showMessage(\"The example output has been copied into the clipboard\");\r\n }\r\n e.clearSelection();\r\n });\r\n });\r\n\r\n $(\".test-form-item input\").change(function () {\r\n addPendingSubmissionMessage($($(this).closest(\"form\")), \"You changed the answer, do not forget to submit it if you want to save the changes\");\r\n const index = $(this).closest(\".problemindexholder\").attr(\"problemindex\");\r\n let test = \"\";\r\n $(this).closest(\"form input\").each(function () {\r\n const test_ = $(this).attr(\"name\");\r\n if (test_ && test_.substring(0, 4) === \"test\") {\r\n test = test_;\r\n }\r\n });\r\n if (index.length > 0 && test.length > 0) {\r\n const indexTest = index + \"::\" + test;\r\n window.changedTests.add(indexTest);\r\n }\r\n });\r\n\r\n $(window).on('beforeunload', function () {\r\n if (window.changedTests.size > 0) {\r\n return 'Dialog text here';\r\n }\r\n });\r\n\r\n autosize($('.test-explanation textarea'));\r\n\r\n $(\".test-example-line\").hover(function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n let top = 1E20;\r\n let left = 1E20;\r\n let problem = $(this).closest(\".problemindexholder\");\r\n $(this).closest(\".input\").find(\".\" + clazz).css(\"background-color\", \"#FFFDE7\").each(function() {\r\n top = Math.min(top, $(this).offset().top);\r\n left = Math.min(left, $(this).offset().left);\r\n });\r\n let testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n if (testCaseMarker.length === 0) {\r\n const html = \"<div class=\\\"testCaseMarker testCaseMarker_\" + end + \" notice\\\"></div>\";\r\n problem.append($(html));\r\n testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n }\r\n if (testCaseMarker) {\r\n testCaseMarker.show()\r\n .offset({top, left: left - 20})\r\n .text(end);\r\n }\r\n }\r\n }\r\n });\r\n }, function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n $(\".\" + clazz).css(\"background-color\", \"\");\r\n $(this).closest(\".problemindexholder\").find(\".testCaseMarker_\" + end).hide();\r\n }\r\n }\r\n });\r\n });\r\n\r\n });\r\n</script>\r\n\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 05:38:05</span> (j3).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/73366/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/73366/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/73366/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/73366/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-73366.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'8122c412cbf95aae',t:'MTY5NjY0NjI4NS4zNjYwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"},"long_tags":{"kind":"string","value":"[\"Greedy algorithms\", \"Implementation problems, programming technics, simulation\", \"Sortings, orderings\", \"Two pointers\"]"},"short_tags":{"kind":"string","value":"[\"greedy\", \"implementation\", \"sortings\", \"two pointers\", \"*1500\"]"},"tutorial_link":{"kind":"string","value":"https://codeforces.com/blog/entry/10476"},"tutorial_page":{"kind":"string","value":"\r\n\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"4f4c31ed5807bbee2a02378cf0944c06\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"h1\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Codeforces Round #225 — Editorial - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n \n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Codeforces Round #225 — Editorial - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/81027/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/81027/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/81027/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/81027/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/81027/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/81027/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/81027/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/81027/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/81027/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/81027/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/81027/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/81027/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/81027/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/81027/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/573cedc6b04c15481941f418269f4057/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='4f4c31ed5807bbee2a02378cf0944c06'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/81027/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fblog%2Fentry%2F10476\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='4f4c31ed5807bbee2a02378cf0944c06'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Pay attention\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n <div style=\"text-align:center;border-bottom: 1px solid rgb(185, 185, 185);margin:0 -0.5em 0.5em -0.5em;padding: 0 1em 0.5em 1em;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 1, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:51:58</span><br/><a href=\"/contestRegistration/1876\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n <div style=\"text-align:center;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 2, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:51:58</span><br/><a href=\"/contestRegistration/1877\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n\r\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div>\r\n\r\n\n <div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\n\r\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='4f4c31ed5807bbee2a02378cf0944c06'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n </label>\r\n </div>\r\n <div style=\"padding: 0 1em 1em 1em;text-align:right;\">\r\n <input style=\"height:1.65em;padding:0 0.75em;\" type=\"submit\" value=\"Find\"/>\r\n </div>\r\n </form>\r\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".handleBox\").autocomplete(\"/data/handles\", {\r\n delay: 200,\r\n width: 200,\r\n selectFirst: false,\r\n matchContains: true,\r\n minChars: 3\r\n });\r\n $(\".handleForm\").attr(\"autocomplete\", \"off\").submit(function () {\r\n var link = \"/profile/userHandle\".replace(\r\n \"userHandle\", $(this).find(\".handleBox\").val()\r\n );\r\n window.location = link;\r\n return false;\r\n });\r\n });\n </script>\n\r\n\r\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Recent actions\n <div class=\"top-links\">\n </div>\n </div>\n <div class=\"recent-actions\">\r\n <ul>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/121073\">Meta Hacker Cup 2023 Round 1</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/.Danet\" title=\"Expert .Danet\" class=\"rated-user user-blue\">.Danet</a> →\r\n <a href=\"/blog/entry/121172\">[TLE on pretest1]</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\" class=\"rated-user user-red\">Pyqe</a> →\r\n <a href=\"/blog/entry/121025\">Codeforces Round #902 (Div. 1, Div. 2, based on COMPFEST 15 — Final Round)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pranshu_Pandya\" title=\"Specialist Pranshu_Pandya\" class=\"rated-user user-cyan\">Pranshu_Pandya</a> →\r\n <a href=\"/blog/entry/121171\">An Interesting Tree Problem</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/sszcdjr\" title=\"Master sszcdjr\" class=\"rated-user user-orange\">sszcdjr</a> →\r\n <a href=\"/blog/entry/119859\">Codeforces Round 896 (Div. 1, Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/119880\">It's Happening! Meta Hacker Cup 2023 Schedule</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/DaviddeGea1\" title=\"Expert DaviddeGea1\" class=\"rated-user user-blue\">DaviddeGea1</a> →\r\n <a href=\"/blog/entry/70917\">Number of ways of dividing an array into 2 parts such that sum of each part is > k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bekh\" title=\"Master Bekh\" class=\"rated-user user-orange\">Bekh</a> →\r\n <a href=\"/blog/entry/74245\">Questions and doubts regarding Aliens DP trick</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a> →\r\n <a href=\"/blog/entry/8192\">Codeforces Round #190 — Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/hocky\" title=\"Candidate Master hocky\" class=\"rated-user user-violet\">hocky</a> →\r\n <a href=\"/blog/entry/95323\">FBHC wuining uw Day? Incwease uw stacc size! (ㅅ´ ˘ `)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/liouzhou_101\" title=\"International Master liouzhou_101\" class=\"rated-user user-orange\">liouzhou_101</a> →\r\n <a href=\"/blog/entry/87598\">Editorial of Codeforces Round #700</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/yeon_gist\" title=\"Newbie yeon_gist\" class=\"rated-user user-gray\">yeon_gist</a> →\r\n <a href=\"/blog/entry/121170\">plusMinusPermutation computing error</a>\r\n <img alt=\"Text created or updated\" title=\"Text created or updated\" src=\"//codeforces.org/s/81027/images/icons/x-update-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/altforminuscontribution\" title=\"Newbie altforminuscontribution\" class=\"rated-user user-gray\">altforminuscontribution</a> →\r\n <a href=\"/blog/entry/121162\">My screen get unexpectedly big, what should I do</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/atcoder_official\" title=\"Unrated, atcoder_official\" class=\"rated-user user-black\">atcoder_official</a> →\r\n <a href=\"/blog/entry/121120\">We will hold UNIQUE VISION Programming Contest 2023 Autumn(AtCoder Beginner Contest 323)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/YouStill_DontKnowMeYet\" title=\"Candidate Master YouStill_DontKnowMeYet\" class=\"rated-user user-violet\">YouStill_DontKnowMeYet</a> →\r\n <a href=\"/blog/entry/117659\">[GYM] Al-Baath Collegiate Programming Contest 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/ankancool\" title=\"Expert ankancool\" class=\"rated-user user-blue\">ankancool</a> →\r\n <a href=\"/blog/entry/121136\">Invitation to AstroByte 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/GeZhiyuan\" title=\"Grandmaster GeZhiyuan\" class=\"rated-user user-red\">GeZhiyuan</a> →\r\n <a href=\"/blog/entry/120943\">Codeforces Round 901 (Div. 1, Div. 2) Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a> →\r\n <a href=\"/blog/entry/120772\">PSA: Increase your stack size before the Meta Hacker Cup, here's how</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/dino_merlin\" title=\"Expert dino_merlin\" class=\"rated-user user-blue\">dino_merlin</a> →\r\n <a href=\"/blog/entry/121145\">Intuitive approach for CEOI Kangaroo?</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/icecuber\" title=\"Grandmaster icecuber\" class=\"rated-user user-red\">icecuber</a> →\r\n <a href=\"/blog/entry/70018\">CSES DP section editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bn00b\" title=\"Newbie Bn00b\" class=\"rated-user user-gray\">Bn00b</a> →\r\n <a href=\"/blog/entry/98820\">[FEATURE REQUEST : ATCODER] TOPICS TAGS AND SORTING BY SOLVE COUNT</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a> →\r\n <a href=\"/blog/entry/121163\">AtCoder Regular Contest 166 Announcement</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/windva\" title=\"Grandmaster windva\" class=\"rated-user user-red\">windva</a> →\r\n <a href=\"/blog/entry/120644\">Codeforces Round 899 (Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Misa-Misa\" title=\"Expert Misa-Misa\" class=\"rated-user user-blue\">Misa-Misa</a> →\r\n <a href=\"/blog/entry/121157\">Someone please help me understand this.</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/shivam565\" title=\"Specialist shivam565\" class=\"rated-user user-cyan\">shivam565</a> →\r\n <a href=\"/blog/entry/108348\">Total number of subarrays with sum atmost k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n </ul>\r\n </div>\r\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/recent-actions\">Detailed →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n</div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li><a\r\n href=\"/profile/fchirica\">fchirica</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/fchirica\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/fchirica\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/fchirica\">Submissions</a></li>\r\n <li><a\r\n href=\"/groups/with/fchirica\">Groups</a></li>\r\n <li><a\r\n href=\"/contests/with/fchirica\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/fchirica\">Problemsetting</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/fchirica\" style=\"text-decoration:none;color:black !important;\">fchirica's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"10531\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/10476\"> <p>Codeforces Round #225 — Editorial</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/fchirica\" title=\"Candidate Master fchirica\" class=\"rated-user user-violet\">fchirica</a>,\r\n <span class=\"format-humantime\" title=\"Jan/20/2014 22:18\">10 years ago</span>,\r\n \r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><h1><a href=\"/contest/384/problem/A\" title=\"Codeforces Round 225 (Div. 2)\">384A - Coder</a></h1><p>Usually, when you don’t have any idea how to approach a problem, a good try is to take some small examples.</p><p>So let’s see how it looks for N = 1, 2, 3, 4 and 5. With C I noted the coder and with * I noted an empty cell.</p><p><img alt=\" \" src=\"/predownloaded/8f/89/8f899efd227362957f283123a7927c7c8a300667.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>By now you should note that answer is N ^ 2 / 2 when N is even and (N ^ 2 + 1) / 2 when N is odd. Good. Generally, after you find a possible solution by taking examples, you need to prove it, then you can code it.</p><p>In order to proof it, one needs to do following steps:</p><p>1/ prove you can always build a solution having N ^ 2 / 2 (or (N ^ 2 + 1) / 2) pieces.</p><p>2/ prove that N ^ 2 / 2 (or (N ^ 2 + 1) / 2) is maximal number – no other bigger solution can be obtained.</p><p>For proof 1/ imagine you do coloring like in a chess table.</p><p><img alt=\" \" src=\"/predownloaded/50/12/50120d92bd0cea3d6a434d09ab4754ea20342351.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>The key observation is that by placing all coders on black squares of table, no two coders will attack. Why? Because a piece placed at a black square can attack only a piece placed at a white square. Again, why? Suppose chess table is 1-based. Then, a square (i, j) is black if and only if i + j is even. A piece placed at (i, j) can attack (i + 1, j), (i – 1, j) (i, j + 1) or (i, j – 1). The sum of those cells is i + j + 1 or i + j – 1. But since i + j is even, i + j + 1 and i + j – 1 are odd, hence white cells.</p><p>Depending on parity of N, number of black cells is either N ^ 2 / 2 or (N ^ 2 + 1) / 2. For N even, one can observe that there are equal amount of black and white cells. Total number of cells is N ^ 2, so number of black cells is N ^ 2 / 2. For N odd, number of black cells is number of white cells + 1. We can imaginary add a white cell to the board. Now, number of black cells will be also equal to number of white cells, so answer is (N ^ 2 + 1) / 2.</p><p>2/ Two coders attack each other if they are placed at two adjacent cells, one black and other one white. One needs to prove that adding more than number from 1/ will cause this to happen. If you place a coder at a white cell, you won’t be able to place at least one coder at a black cell, so in best case you don’t win anything by doing this. Hence, it’s optimally to place all coders on same color cells. Since cells colored in black are always more or equal to white ones, it’s always optimally to choose black color. But number from 1/ is the number of cells having black color. Adding one more piece will force you to add it to a white color cell. Now, you’ll have a piece placed at a black colored cell and one placed at an adjacent white colored cell, so two coders will attack. Hence, we can’t place more than number from 1/ pieces.</p><p>Code: <a href=\"http://pastie.org/8651801\">http://pastie.org/8651801</a></p><h1><a href=\"/contest/384/problem/B\" title=\"Codeforces Round 225 (Div. 2)\">384B - Multitasking</a></h1><p>Let’s start by saying when array A[] is sorted:</p><p>1/ is sorted in ascending order when i < j and A[i] <= A[j]. It is NOT sorted when i < j and A[i] > A[j].</p><p>2/ is sorted in descending order when i > j and A[i] <= A[j]. It is NOT sorted when i > j and A[i] > A[j].</p><p>Iahub can choose 2 indices i, j and swap values when A[i] > A[j]. If A[i] <= A[j], he’ll ignore operation. Hence, if he wants to sort all arrays in ascending order, he chooses indices i, j when i < j and perform operation. Otherwise, in all his operations he uses indices i, j such as i > j. A “good” operation is when choosing indices i < j for ascending order sorting and i > j for descending order sorting. By doing only good operations, after an array is sorted, it will stay sorted forever (for a sorted array, all good operations will be ignored).</p><p>From here we get our first idea: use any sorting algorithm you know and sort each array individually. When print swaps done by sorting algorithm chosen, print them as good operations. However, sorting each array individually can cause exceeding M * (M — 1) / 2 operations limit. Another possible solution would be, after you did an operation to an array, to update the operation to all arrays (you printed it, so it counts to M * (M — 1) / 2 operations limit; making it to all arrays will help sometimes and in worst case it won’t change anything). However, you need to code it very careful in order to make this algorithm pass the time limit. Doing this in a contest is not the best idea, especially when implementation could be complicated and you have no guarantee it will pass time limit.</p><p>So what else can we do? We can think out of box. Instead of sorting specific N arrays, you can sort all possible arrays of length M. Find a sequence of good operations such as, anyhow I’d choose an array of size M, it will get sorted ascending / descending.</p><p>I’ll show firstly how to do for ascending sorting. At position 1 it needs to be minimal element. Can we bring minimal element there using good operations? Yes. Just do “1 2” “1 3” “1 4” ... “1 M”. It basically compares element from position 1 to any other element from array. When other element has smaller value, swap is done. After comparing with all M elements, minimal value will be at position 1. By now on I’ll ignore position 1 and move to position 2. Suppose array starts from position 2. It also needs minimal value from array, except value from position 1 (which is no longer in array). Hence doing “2 3” “2 4” “2 5” ... “2 M” is enough, by similar reasons. For a position i, I need minimal value from array, except positions 1, 2, ..., i – 1. I simply do “i i+1” “i i+2” ... “i M-1” “i M”. By arriving at position i, array will be sorted ascending. The algorithm is simply:</p><p>for (int i = 1; i < M; ++i)</p><p>for (int j = i + 1; j <= M; ++j)</p><p>cout << i << “ “ << j << “\\n”;</p><p>This algorithm does exactly M * (M — 1) / 2 moves.</p><p>Can you find out how to sort array in descending order? Try to think yourself, then if you don’t get it read next. At first position of a descending array it needs to be maximal value. Similarly to ascending order, we can do “2 1” “3 1” “4 1” ... “M 1”. When I’m at a position i and I compare its value to value from position 1, doing operation “i 1” checks if A[i] > A[1]. If so, it swaps A[i] and A[1], so position 1 will contain now the maximum value so far. Similarly to logic from ascending order, when I’m at position i, I need maximum value from array except positions 1, 2, ..., i – 1, so I do “i+1 i” “i+2 i” ... “M i”. Algorithm is:</p><p>for (int i = 1; i < M; ++i)</p><p>for (int j = i + 1; j <= M; ++j)</p><p>cout << j << “ “ << i << “\\n”;</p><p>Obviously, this does as well M * (M — 1) / 2 operations worst case. All algorithm is about 10 lines of code, much better than other solution, which requires two manually sorts and also has a chance to exceed TL.</p><p>Code: <a href=\"http://pastie.org/8651809\">http://pastie.org/8651809</a></p><h1><a href=\"/contest/384/problem/C\" title=\"Codeforces Round 225 (Div. 2)\">384C - Milking cows</a></h1><p>A good strategy to approach this problem is to think how optimal ordering should look like. For this, let’s calculate for each 2 different cows i and j if cow i needs to be milked before or after cow j. As we’ll show, having this information will be enough to build optimal ordering. It is enough to consider only cases when i < j, case when i > j is exactly the opposite of case i < j. For formality, I’ll call the optimal ordering permutation and lost milk the cost of permutation.</p><p>So, for an optimal permutation P let’s take 2 numbers i < j and see in which cases i should appear before j in permutation (i is before j if P[pos1] = i, P[pos2] = j and pos1 < pos2; otherwise we’ll call i is after j). We have 4 possible cases:</p><p>1/ A[i] = 0 and A[j] = 0</p><p>If we put i before j, no additional cost will be added. Since j is in right of i and i only adds cost when it finds elements in left of i, j won’t be affected when processing i. When processing j, i will be already deleted so it won’t affect the cost either. Hence, we can put i before j and no cost will be added.</p><p>2/ A[i] = 0 and A[j] = 1</p><p>Here, i and j can appear in arbitrary order in permutation (i can be before or after j). No matter how we choose them, they won’t affect each other and cost will remain the same.</p><p>3/ A[i] = 1 and A[j] = 0</p><p>As well, here i and j can appear in arbitrary order. If we choose i first, j will be in right of it, so cost of permutation will increase by one. If we choose j first, i will be in left of it so cost of permutation will increase as well. No matter what we do, in this case cost of permutation increases by 1.</p><p>4/ A[i] = 1 and A[j] = 1</p><p>Here, i needs to be after j. This adds 0 cost. Taking i before j will add 1 cost to permutation (since j is in right of i).</p><p>Those 4 cases show us how a minimal cost permutation should look. In a permutation like this, only case 3/ contributes to final cost, so we need to count number of indices i, j such as i < j and A[i] = 1 and A[j] = 0 (*). If we show a permutation following all rules exists, task reduces to (*).</p><p>By cases 2/ and 3/ it follows that in an optimal permutation, it only matters order of elements having same value in A[]. We can put firstly all elements having value 0 in A[], then all elements having value 1 in A[]. We can order elements having value 0 by case 1/ and elements having value 1 by case 4/. More exactly, suppose i1 < i2 < ... < im and (A[i1] = A[i2] = ... = A[im] = 0) and j1 > j2 > ... > jn (A[j1] = A[j2] = ... = A[jn] = 1). Then, a permutation following all rules is {i1, i2, ..., im, j1, j2, ..., jn}. This permutation can always be built.</p><p>Hence, task reduces to (*): count number of indices i, j such as i < j and A[i] = 1 and A[j] = 0. We can achieve easily an O(N) algorithm to do this. Let’s build an array cnt[j] = number of 0s in range {j, j + 1, ..., N} from array A. We can easily implement it by going backwards from N to 1. The result is sum of cnt[i], when A[i] = 1.</p><p>Code: <a href=\"http://pastie.org/8651813\">http://pastie.org/8651813</a></p><h1><a href=\"/contest/384/problem/D\" title=\"Codeforces Round 225 (Div. 2)\">384D - Volcanoes</a></h1><p>Our first observation is that if there is a path from (1, 1) to (N, N), then the length of path is 2 * N – 2. Since all paths have length 2 * N – 2, it follows that if there is at least one path, the answer is 2 * N – 2 and if there isn’t, the answer is -1. How to prove it? Every path from (1, 1) to (N, N) has exactly N – 1 down directions and exactly N – 1 right directions. So, total length for each path is N – 1 + N – 1 = 2 * N – 2. </p><p>So we reduced our problem to determine if there is at least one path from (1, 1) to (N, N). This is the challenging part of this task, considering that N <= 10 ^ 9. How would you do it for a decently small N, let’s say N <= 10^3 . One possible approach would be, for each row, keep a set of reachable columns. We could easily solve this one by doing this: if (i, j) denotes element from ith row and jth column, then (i, j) is (is not) reachable if:</p><p>if (i, j) contains a volcano, then (i, j) is not reachable. Otherwise, if at least one of (i – 1, j) and (i, j – 1) is reachable, then (i, j) is reachable. Otherwise, (i, j) is not reachable.</p><p>What’s the main problem of this approach? It needs to keep track of 10^9 lines and in worst case, each of those lines can have 10^9 reachable elements. So, worst case we need 10^9 * 10^9 = 10^18 operations and memory.</p><p>Can we optimize it? We can note for beginning that we don’t need to keep track of 10^9 lines, only m lines are really necessarily. We need only lines containing at least one obstacle (in worst case when each line contains only one obstacle, we need m lines). How to solve it this way? Suppose line number x contains some obstacles and lines x + 1, x + 2, x + 3 do not contain any obstacle. Suppose we calculated set S = {y | cell (x, y) is reachable}. How would look S1, S2, S3 corresponding to lines x + 1, x + 2, x + 3? For S1, we can reach cell (x + 1, ymin), where ymin is minimal value from set S. Then, we can also reach {ymin + 1, ymin + 2, ..., N}, by moving right from (x + 1, ymin). So S1 = {ymin, ymin + 1, ..., N}. How do S2 and S3 look? It’s easy to see that they’ll be as well {ymin, ymin + 1, ..., N}. So we get following optimization: suppose set of lines containing at least one obstacle is {L1, L2, ..., Lk}. We need to run algorithm only for lines L1, L1 + 1, L2, L2 + 1, L3, L3 + 1, ..., Lk, Lk + 1.</p><p>It looks like we didn’t make anything with this optimization. Even if we calculate for m lines, each line can still have 10^9 reachable positions. So worst case we perform 10^14 operations. We need something better for managing information from a line. You can note that for a given line y, there are a lot of positions having consecutive values. There are a lot of positions (x, y) and (x, y + 1) both reachable. This should give us following idea: what if instead of keeping reachable positions, we keep reachable ranges? That is, for each line x we keep a set of ranges S = {(a, b) | all cells (x, k) with a <= k <= b are reachable}. </p><p>How many ranges can it be for a line? If the line contains m obstacles, there are m + 1 ranges. Suppose for line x all cells are reachable, but for line x + 1 cells (x + 1, 3) (x + 1, 5) (x + 1, N – 1) are blocked. Then, the ranges of reachable cells are [1, 2] [4, 4], [6, N – 2] and [N, N]. By now, we get worst case m lines and worst case each line having m elements, so in worst case we’d have to handle m * m = 10 ^ 10 events. This may still look too much, but happily this bound is over estimated. If a line has o obstacles, there can be at most o + 1 ranges. If lines L1, L2, ..., Lk have {o1, o2, ..., ok} obstacles, there’ll be at most o1 + o2 + ... + ok + k ranges. But o1 + o2 + ... + ok = m and also k is at most m (proved above why we’re interested in at most m lines), so in worst case we get m + m = 2 * m ranges. Yaay, finally a decent number of states for this problem :)</p><p>So, we iterate each line we’re interested in. Let’s find set of ranges for this line, thinking that all cells from line above are reachable. This is easy to do. After we get our ranges like all cells from above can be visited, let’s think how having obstacles above can influence current ranges. After adding ranges from above, current ranges can’t increase (obviously), they can only decrease, remain the same or some of them can become empty. So, let’s take each range [a, b] from current line and see how it will transform after adding ranges from previous line. </p><p>Given range [a, b], it can transform only in [a’ , b] with a’ >= a. If a’ > b, then obviously range is empty. Why second number of range keeps constant? Let a’ smallest reachable column from current line which is in range [a, b]. It’s enough to check a’ >= a, as if a’ > b, range will be empty. It’s obviously why we need to keep a’ smallest value possible >= a: we’re interested to keep range as big as possible and as less as we cut from left, as big it is. Once we’ve found a’ in range [a, b] (or a’ > b if range is empty) all cells {a’ + 1, a’ + 2, ..., b} are reachable as well by going right from a’, so if interval is not empty, then second number defining it remains b.</p><p>Next question is how to find a’ fast enough. In order a point a’ to be reachable on current range, it also needs to exist a range on previous line containing it. If the range from previous line is [pa, pb] then a’ needs to follow 3 conditions:</p><p>a’ minimal such as</p><p>pa <= a’ <= pb</p><p>a’ >= a</p><p>What if instead of finding a’ we find [pa, pb]? Then a’ is max(pa, a). In order a’ to be as small as possible, since a is constant, pa needs to be as small as possible. So we reduced it to:</p><p>pa minimal pb >= a’ >= a <=> pb >= a</p><p>Intervals from previous line are disjoint, no 2 intervals cross each other. It means that if pb is minimal, than pa is minimal too (if we increase pb, then pa will increase too, so it won’t be minimal). Hence, you need to find an interval [pa, pb] such as pb is minimal and pb >= a. Then, a’ is max(a, pa). This is easy to do if we sort all intervals from previous line increasing by second value (pb), then we binary search for value a. </p><p>Finally, after running algorithm for all lines, last range from last line has second number N (assuming ranges are sorted increasing by second value), then there exist a path, otherwise there does not exist. This algorithm should run O(m * logm) worst case, good enough to pass. </p><p>Code: <a href=\"http://pastie.org/8651817\">http://pastie.org/8651817</a></p><h1><a href=\"/contest/384/problem/E\" title=\"Codeforces Round 225 (Div. 2)\">384E - Propagating tree</a></h1><p>This is kind of task that needs to be break into smaller subproblems that you can solve independently, then put them together and get solution.</p><p>Let’s define level of a node the number of edges in the path from root to the node. Root (node 1) is at level 0, sons of root are at level 1, sons of sons of root are at level 2 and so on.</p><p>Now suppose you want to do an operation of type 1 to a node x. What nodes from subtree of x will be added +val (a positive value)? Obviously, x will be first, being located at level L. Sons of x, located at level L + 1 will be added –val. Sons of sons, located at level L + 2, will be added value +val again. So, nodes from subtree of x located at levels L, L + 2, L + 4, ... will be added a +val, and nodes located at levels L + 1, L + 3, L + 5 will be added a –val. Let’s take those values of L modulo 2. All nodes having remainder L modulo 2 will be added a +val, and nodes having reminder (L + 1) modulo 2 will be added –val. In other words, for a fixed x, at a level L, let y a node from subtree of x, at level L2. If L and L2 have same parity, +val will be added to y. Otherwise, -val will be added to y.</p><p>From here we have the idea to split nodes of tree in 2 sets – those being located at even level and those being located at odd level. What still makes the problem hard to solve? The fact that we have a tree. If nodes from a subtree would be a contiguous sequence instead of some nodes from a tree, problem would be simpler: the problem would reduce to add / subtract values to all elements of a subarray and query about a current value of an element of array. So, how can we transform tree to an array, such as for a node x, all nodes from subtree of x to be a subarray of array?</p><p>The answer is yes. We can do this by properties of DFS search. Before reading on, make sure that you know what is discovery time and finish time in a DFS search. Let’s build 3 arrays now – discover[], representing nodes in order of their discover times (a node is as before in discover as it has a small discover time), begin[] = for a node, in which time it was discovered and end[] = what’s last time of a discovered node before this node finishes. For a subtree of x, all nodes in the subtree are nodes in discover from position begin[x] to end[x].</p><p>Example: suppose you have tree 1-5; 1-6; 6-7; 6-4; 4-2; 4-3</p><p>Discover is {1, 5, 6, 7, 4, 2, 3}.</p><p>begin is {1, 6, 7, 5, 2, 3, 4}.</p><p>end is {7, 6, 7, 7, 2, 7, 4}.</p><p>What’s subtree of node 6? elements of discover from position begin[6] to end[6]. In this case, from 3 to 7, so elements {6, 7, 4, 2, 3}. You can see it’s correct and take more examples if you want :)</p><p>Now, we reduced problem to: you’re given an array A. you can perform 2 operations:</p><p>1/ increase all elements from a range [x, y] to a value val (val can be negative, to treat subtractions)</p><p>2/ what’s current value of an element from position pos.</p><p>Those who solved “Iahub and Xors” from my last round, CF 198, should probably say they saw something similar before. If you didn’t solve problem before, I encourage you to do it after you solve this one, it uses a similar idea to what will follow now. Also, if you don’t know Fenwick trees, please read them before moving on. An alternative would be for this task using segment trees with lazy update, but I see this one more complicated than needed.</p><p>I’ll use now a not so common approach when dealing with data structures. Instead of keeping in a node the result, like you usually do, I’ll keep just an auxiliary information. So what algorithm proposed does:</p><p>Let A an array, initially with all elements 0.</p><p>When you need to update range [x, y] with value val, you simply do A[x] += val and A[y + 1] -= val.</p><p>When you need to answer a query about position pos, you output A[1] + A[2] + ... + A[pos].</p><p>Implemented brute force, you get O(1) per update and O(N) per query. However, these both are operations supported by a Fenwick tree, so you can get O(logN) per operation.</p><p>It may not be very clear why this algorithm works. Let’s take a closer look: an update needs to add value val only to range [x, y]. When you query a position pos, let’s see if algorithm handles it correctly:</p><p>1/ pos < x. In this case, result must not be affected by my update. Since pos < x and I only updated 2 values with indices >= x, when doing A[1] + A[2] + ... + A[pos] it won’t matter at all I did that update – at least not for this query.</p><p>2/ x <= pos <= y. Here, for a pos, I need to add value val only once. We add it only at A[x] – in this way it will be counted once, and it will be considered for each elements from range [x, y] (since an element at position p from range [x, y] has p >= x, in A[1] + A[2] + ... + A[p] I’ll have to consider A[x]).</p><p>3/ pos > y. Here I don’t have to consider the query. But it would be considered when processing A[x]. But if I add to A[y + 1] value –val I’ll just cancel the value previously added.</p><p>Code (actually we use just one Fenwick tree instead of 2, can you think why it works? :) ) : <a href=\"http://pastie.org/8651824\">http://pastie.org/8651824</a></p><h1><a href=\"/contest/383/problem/D\" title=\"Codeforces Round 225 (Div. 1)\">383D - Antimatter</a></h1><h2>Author's solution</h2><p>The problem is: given an array, iterate all possible subarrays (all possible elements such as their indexes are consecutive). Now, for a fixed subarray we need to know in how many ways we can color its elements in black and white, such as sum of black elements is equal to sum of white elements. The result is sum of this number, for each subarray.</p><p>Let’s solve an easier problem first. This won’t immediately solve the harder version, but it will be useful later. Suppose you’ve fixed a subarray. In how many ways can you color it with black and white? Suppose subarray has N elements and sum of them is M. Also, suppose for a coloring, sum of blacks is sB and sum of whites is sW. For coloring to be valid, sB = sW. But we also know that sB + sW = M (because each element is colored by exactly one color). We get that 2 * sB = M, so sB = M / 2. The problem is now: in how many ways can we color elements in black such as sum of blacks is M / 2 (after we fix a black coloring, we color with white non colored elements; sum of white colored elements is also M / 2). This is a well known problem: Knapsack problem. Let ways[i][j] = in how many ways one can obtain sum j from first i elements. When adding (i + 1) object, after ways[i] is calculated, for a fixed sum j we can do 2 things: add (i + 1) object to sum j or skip it. Depending of what we chosen, we add value ways[i][j] to ways[i + 1][j + value[i + 1]] or to ways[i + 1][j]. The result is in ways[N][M / 2]. This works in O(N * M) time.</p><p>An immediate solution can be obtained now: take all subarrays and apply above approach. This leads to an O(N ^ 2 * M ^ 2) solution, which is too much. One can reduce complexity to O(N ^ 2* M) by noting that processing subarray [i, j] can be done with already calculated values for subarray [i, j – 1]. Hence, instead of adding N elements, it’s enough to add 1 element to already calculated values (element from position j). Sadly, O(N ^ 2 * M) is still too slow, so we need to find something better. The solution presented below will look forced if you didn’t solve some problems with this technique before. It’s hard to come with an approach without practicing this kind of tasks. But don’t worry, as much as you practice them, as easily you’ll solve those problems.</p><p>We’ll solve task by divide and conquer. Complexity of this solution is O(N * M * logN). Let f(left, right) a function that counts number of colorings for each subarray [i, j], such as subarray [i, j] is included in subarray [left, right] (left <= i <= j <= right). Answer is in f(1, N). The trick is to define a value med = (left + right) / 2 (very frequent trick in divide and conquer problems, called usually a median). We can next classify [i, j] subarrays in 3 types:</p><p>1/ i <= med j <= med</p><p>2/ i > med j > med</p><p>3/ i <= med j > med</p><p>We can solve 1/ and 2/ by calling f(left, med) and f(med + 1, right). The remained problem is when i <= med and j > med. If we solve 3/ in O((right – left) * M) time, this will be enough to overall achieve O(N * M * logN) (for this moment trust me, you’ll see later why it’s so :) ).</p><p>Let’s denote by i1 last i1 elements from subarray [left, med]. Also, let’s note by i2 first i2 elements from subarray [med + 1, right]. For example, let left = 1 and right = 5, with array {1, 2, 3, 4, 5}. med is 3 and for i1 = 2 and i2 = 1, “left” subarray is {2, 3} and “right” subarray is {4}. By iterating i1 from 1 to med – left + 1 and i2 from 1 to right – med and then unite subarrays i1 and i2, we obtain all subarrays described in 3/ . Let’s denote by j1 sum of a possible black coloring of i1. Similarly, j2 is sum of a possible black coloring of i2.</p><p>Suppose we fixed i1, i2, j1 and j2. When it’s the coloring valid? Let S sum of united subarrays i1 and i2 (S = value[med – i1 + 1] + value[med – i1 + 2] + ... + value[med] + value[med + 1] + ... + value[med + i2 – 1] + value[med + i2]). Now it’s time to use what I explained at the beginning of solution. The coloring is good only when j1 + j2 = S / 2. We can rewrite the relation as 2 * (j1 + j2) = sum_of_elements_from_i1 + sum_of_elements_from_i2. We can rewrite it even more:</p><p>2 * j1 + 2 * j2 — sum_of_elements_from_i1 — sum_of_elements_from_i2 = 0</p><p>2 * j1 – sum_of_elements_from_i1 = sum_of_elements_from_i2 – 2 * j2 = combination_value</p><p>This relation is the key of solving problem. You can see now that relation is independent in “left” and “right” side. We calculate left[i1][j1] and right[i2][j2] = in how many ways can I obtain sum of blacks j1 (j2) from first i1 (i2) from left (right) side. Let’s calculate also count[value] = in how many ways can I obtain combination_value equal to value in the right side. For some fixed (i2, j2) I add to count[sum_of_elements_from_i2 – 2 * j2] value right[i2][j2]. In this way count[] is calculated correctly and completely. Now, let’s fix a sum (i1, j1) in the left side. We’re interested how many good colorings are such as there exist a coloring of j1 in i1 elements (the endpoint of “left” is fixed to be i1 and I need to calculate endpoints i2 for right, then to make colorings of i2). A coloring is good if combination_value of (i1, j1) and (i2, j2) is equal. Hence, I need to know in how many ways I can color i1 elements to obtain sum j1 and also I need to know in how many ways I can color elements from right to obtain same combination_value as it’s in the left. It’s not hard to see that answer for a fixed (i1, j1) is left[i1][j1] * count[2 * j1 – sum_of_elements_from_i1]. This takes O((right – left) * M) time.</p><p>The only thing remained in the problem is to see why complexity is O(N * M * logN). We can assume N is a power of 2 (it not, let’s round N to smallest power of 2 bigger than N; complexity for N is at least as good as complexity for this number). Draw a binary complete tree with N nodes. Each node corresponds to an appeal of f(). For a level, exactly O(N * M) operations are performed. To see why:</p><p>For level 1, there’ll be 1 node performing N * M operations.</p><p>For level 2, there’ll be 2 nodes performing (N / 2) * M operations. Summing up we get O(N * M).</p><p>For level 3, there’ll be 4 nodes performing (N / 4) * M operations. Summing up we get O(N *M) as well.</p><p>and so on.</p><p>So for each level we perform O(N * M) operations. A binary complete tree has maximum O(logN) levels, so overall complexity is O(N * M * logN).</p><p>Code: <a href=\"http://pastie.org/8651826\">http://pastie.org/8651826</a></p><h2>Solution fount by contestants</h2><p>This was totally unexpected to us :) Good job finding it, you guys are really smart. </p><p>We observe that x units of antimatter is the same thing as -x units of matter. Then we can consider that an element produces either x or -x units of matter. A valid substring is one that can have the sum of the elements 0. The problem is reduced to finding how many different substrings can we have with sum 0 (a substring is different than another one if it has different indices, or if at least one element produces matter in one and antimatter in the other).</p><p>This problem can be solved with dynamic programming. We will hold D[i][j] = the number of substrings that end in element i, and have sum j. It's easy to see that D[i + 1][j] = D[i][j — x] + D[i][j + x], where x is the value of the current element (we can put either -x or x). After we finish computing all the values for current i, we add to the solution D[i][0] (how many valid substrings do we have). After that, we add 1 to D[i][0], meaning that there is an empty substring starting at position i (however, we don't need to add it to the answer).</p><p>For a code, check passing submissions during contest. </p><h2><a href=\"/contest/383/problem/E\" title=\"Codeforces Round 225 (Div. 1)\">383E - Vowels</a></h2><h2>Author's solution</h2><p>Let's iterate over all possible vowel sets. For a given set {x1, x2, ..., xk} we're interested in number of correct words from dictionary. After a precalculation, we can do it in O(k).</p><p>Suppose our current vowel set is {x1, x2, ..., xk}. How many words are covered by the current vowels? By definition, we say a word is covered by a set of vowels if at least one of 3 letters of word is in vowel set. We can calculate this number using principle of inclusion and exclusion. We’ll denote by |v1, v2, v3, ...| = number of words containing ALL of vowels v1, v2, v3, ... . Using principle of inclusion and exclusion we get:</p><p>number_of_words_covered = |x1| + |x2| + .. + |xk| — |x1, x2| — |x1, x3| — .... + |x1, x2, x3| + |x1, x2, x4| + .... + |xk-2, xk-1, xk|. This formula is simply a reformulation of principle of inclusion and exclusion. You can easily observe that |v1, v2, ..., vk| makes sense only when k is at most 3, as no word from input can contain 4 or more letters (and hence can’t contain 4 or more vowels). </p><p>Example:</p><p>Suppose words are abc, abd and bcd. </p><p>|a| = 2 (first 2 words both contain character a).</p><p>|a, b| = 2 (as well, first 2 words contain characters a and b).</p><p>|b| = 3 (all 3 words contain character b).</p><p>|a, b, d| = 1 (only second word contains all 3 characters).</p><p>Also, note how principle of inclusion and exclusion works. number of words covered for vowels {a, b} is |a| + |b| — |a, b| = 2 + 3 – 2. Indeed, answer is 3.</p><p>We divide our problem in 3 subproblems. First one, for a vowel set, compute sum of |a|, where a is a letter from subset. Second, compute sum of |a, b|, where both a and b are letters from set. Third, compute sum of |a, b, c|, where a, b, c are letters from set. As stated, the answer is number_from_1st_step + number_from_3rd_step – number_from_2nd_step. If you followed me, you’ll see that we want to compute results for each subproblem in O(queryLetters).</p><p>First subproblem can be solved trivially in O(queryLetters). Let array single[], with following meaning: single[c] is how many words contain character c. It can be trivially precomputed in O(24 * N). Note that if a word contains twice/third times a character c, it needs to be counted only one (e.g. word aba will add only 1 to single[a]). For compute result of this subproblem for a given set of vowels, I’ll take all letters from set. If letter belongs to set, I add to result single[letter]. This step can be also be solved in O(1), but there’s no need, since other subproblems allow only an O(queryLetters) solution. </p><p>For second and third subproblems it’s a little more difficult. I’ll present here how to solve second subproblem and some hints for third one (if you understand second, with hints you should be able to solve third one by your own).</p><p>Similarly to first step, I’ll define a matrix double[c1][c2] = how many words contain both characters c1 and c2. A trivially solution would be, for a given vowel set, take all combinations of letters c1 and c2 that belong to set and add to result value double[c1][c2]. However, this solves each query in O(queryLetters^2), which is too slow.</p><p>Note, if we’d have 12 letters, instead of 24, this approach would be fast enough. From here it comes a pretty classical idea in exponential optimization: meet in the middle attack. We split those 24 letters in 2 groups: first 12 letters and last 12 letters. The answer for a subset is sum of double[c1][c2] (when c1 and c2 belong to current vowel set) when</p><p>1/ c1 and c2 belong to first 12 letters</p><p>2/ c1 and c2 belong to last 12 letters</p><p>3/ c1 belongs to first 12 letters and c2 belongs to last 12 letters</p><p>1/ and 2/ can be immediately precalculated as stated above, in O(2 ^ 12 * 12 ^ 2). We’ll remember results for each half using bitmasks arrays. Let Half1[mask] = sum over double[c1][c2], when c1 and c2 are in first 12 letters and correspond to 1 bits of mask. Half2[mask] is defined similarly, but for last 12 letters (e.g. subset {a, c, d} corresponds to bitmask 2^0 + 2^2 + 2^3 = 13 in first half and subset {m, n, p} corresponds to bitmask 2^0 + 2^1 + 2^3 = 11 for second half). Now, for a given subset, one can answer first 2 parts in O(queryCount) worst case (read input for a query and convert it to bitmasks). </p><p>How to answer 3? With another precalculation, of course. We know c1 letter needs to be in first 12 letters and c2 needs to be in last 12 letters. The precalculation we do here is: mixed_half[mask][i] = sum over |c1, c2|, when c1 belongs to first half and is a 1 bit of mask and c2 is i-th character of second half. Hence, for a query, we can fix character from second half (c2, by iteration of query letters from second half) and know sums of |c1, c2| between it and all available characters from first half after we do this precalculation. Also, precalculation is done trivially in O(2 ^ 12 * 12^2): fix mask, fix i and then iterate over 1 bits from mask and add double[c1][c2]. </p><p>Third subproblem is left, but it can be done similarly to second one. Instead of double[c1][c2], we’ll have triple[c1][c2][c3] = how many words contain all 3 characters c1, c2 and c3? We also do meet in the middle here, divide those 24 letters into 2 sets of 12 letters. We have 4 cases:</p><p>1/ c1, c2, c3 belong to first half</p><p>2/ c1, c2, c3 belong to second half</p><p>3/ c1, c2 belong to first half and c3 to second half</p><p>4/ c1 belongs to first half and c2, c3 to second half</p><p>1/ and 2/ are done brute force, like in second subproblem (the only difference is we choose 3 characters instead of 2, having complexity O(2 ^ 12 * 12 ^ 3)). For 3/ and 4/ we also precompute 2 matrixes: </p><p>mixed_two_one[mask][i] = c1 and c2 belong to mask from first half and c3 is i-th character from second half </p><p>and </p><p>mixed_one_two[mask][i] = c1 is i-th character from first half and c2, c3 belong to mask from second half. </p><p>Those can also be calculated in O(2 ^ 12 * 12^3).</p><p>So precalculation part is O(2 ^ 12 * 12 ^ 3) = 7077888 operations.</p><p>For calculate answering queries complexity, take all numbers from 0 to 2^24 — 1 and sum their bit count. This is a well known problem, the sum is 0 * C(24, 0) + 1 * C(24, 1) + ... + 24 * C(24, 24) = 201326592. In total we get 208404480 operations. C++ source makes them in 2 seconds. </p><p>Code: <a href=\"http://pastie.org/8651829\">http://pastie.org/8651829</a></p><h2>Solution fount by contestants</h2><p>Like in D1 D task, official solution was over complicated. This solution is more simple to understand, code and it's more elegant. If someone wants to complicate his life, (s)he can code also official solution :)</p><p>Let's start by assigning a bitmask to each word in following way: ith bit is 1 if and only if letter ('a' + i) appears in the current word. For example, for word acd, its bitmask is 2^0 + 2^2 + 2 ^ 3 = 13 and for word aab its bitmask is 2^0 + 2^1 = 3. After reading the words from dictionary, we store a matrix cnt[mask] = how many words from dictionary correspond to mask?</p><p>We iterate bitmasks from 0 to 2^24 — 1, this time corresponding to each possible question of Iahubina. Let's focus on a bitmask X. We need to get sum of cnt[mask], when mask and X share at least one common bit having value 1 (formally (X AND mask) > 0). In order to do this, we need a reduction which may be not so obvious. </p><p>What if instead of counting all words containing at least one of vowels {w1, w2, ..., wk} we count all words which don't contain ANY of vowels {w1, w2, ..., wk}? Suppose this number is ret. Then, all words containing at least one of vowels is N — ret. From all words, we erase those words which do not contain any vowels from set {w1, w2, ..., wk} (and which obviously are wrong words). Obviously, it's left only words containing at least one vowel, so good words. Now, for a word not to contain any of vowels {w1, w2, ..., wk} it needs to contains ONLY vowels from set {"a", "b", "c", ..., "x"} \\ {w1, w2, ..., wk} (set of allowed letters from which we erased vowels w1, w2, ..., wk}. </p><p>And this is reduction we needed. For a bitmask X we need to calculate sum of cnt[mask], where mask is a subset of X (we can set some bits from X from 1 to 0 in order to obtain mask). For a mask, let's keep this sum in res[mask]. We can calculate res array using divide and conquer.</p><p>Let's make a function solve(left, right), which completes array res in the way described above, if we consider only elements cnt[k] with left <= k < right (for simplicity, I'll consider elements which do not lie in this range to be equal to 0). Now we need to solve for a range [left, right]. Let's have in res1[] = solve(left, med) and in res2[] = solve(med, right), where med = (left + right) / 2. We need to put together res1[] and res2[] in order to obtain res[].</p><p>for (int i = left; i < med; ++i) res[i] = res1[i];</p><p>Numbers in [left, med] have most significant bit equal to 0. We can only keep it 0 and add what we calculated before. We can't add any element from res2[], because those elements have most significant bit equal to 1 and we're not allowed to change bit 0 into bit 1.</p><p>for (int i = med; i < right; ++i) res[i] = res1[i — med] + res2[i];</p><p>Here, most significant bit is 1. Adding res1[] corresponds to changing bit from 1 to 0, adding res2[] corresponds to leaving bit 1.</p><p>Of course, we need to threat the base case here, too. When left + 1 = right, res[left] = cnt[left]. We can keep only one array res[] instead of 3, I explained it this way only for simplicity. Also, there is no need for keeping separate arrays for res[] and cnt[], one can solve all task with only one array. In order to get res[], we simply call solve(0, 2^24).</p><p>Complexity of solution is O(2 ^ 24 * 24). I leave the proof homework, it's almost identical to complexity proof of D1 D "Author solution" (that with building a binary tree).</p><p>For a reference solution, check <a class=\"rated-user user-red\" href=\"/profile/Endagorion\" title=\"Grandmaster Endagorion\">Endagorion</a>'s AC source during contest. </p></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/384\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 225 (Div. 2)</a> </span>\r\n </div>\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/383\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 225 (Div. 1)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-12457-10531\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"12457\",\n blogEntryId: \"10476\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n <div style=\"font-size: 1.1rem;line-height: 11px;\">\r\n <img style=\"vertical-align: middle;\" src=\"//codeforces.org/s/81027/images/blog/tags.png\" title=\"Tags\" alt=\"Tags\"/>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=codeforces\" class=\"tag notice\" style=\"text-decoration: none;\">codeforces</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=225\" class=\"tag notice\" style=\"text-decoration: none;\">225</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=editorial\" class=\"tag notice\" style=\"text-decoration: none;\">editorial</a>\r\n </span>\r\n </div>\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-10531\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+418</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-10531\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/fchirica\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/fchirica\">\n fchirica\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Jan/20/2014 22:18\">10 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/10476#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/10476#comments\">\n 52\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"10547\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (45)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158582\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PAP\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/78534/avatar/d5bcc04085999f83.jpg'/> </a>\n <div><a href=\"/profile/PAP\" title=\"Candidate Master PAP\" class=\"rated-user user-violet\">PAP</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 22:40\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158582\" href=\"?#comment-158582\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158582\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"32\"\r\n data-commentUserId=\"78534\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+32</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158582\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>perfect editorial! thanks a lot!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158582 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158582 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158582\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158591\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/eduardische\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2320/avatar/3ac70493aa90ad2e.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/eduardische\" title=\"International Master eduardische\" class=\"rated-user user-orange\">eduardische</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 22:48\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158591\" href=\"?#comment-158591\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"158591\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"158591\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"10\"\r\n data-commentUserId=\"2320\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+10</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158591\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Just would like to report a typo in 383D contestants' solution: the formula computes D[i+1][j] and not D[i][j]. Thanks for the quick editorial!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158591 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158591 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158591\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158596\" commentParentId=\"158591\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/fchirica\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/57267/avatar/4e655c69b8ad66c2.jpg'/> </a>\n <div><a href=\"/profile/fchirica\" title=\"Candidate Master fchirica\" class=\"rated-user user-violet\">fchirica</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 22:52\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158596\" href=\"?#comment-158596\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-158591\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158596\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"15\"\r\n data-commentUserId=\"57267\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+15</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158596\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks. Fixed. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158596 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158596 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158596\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158598\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Mikester\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/109566/avatar/401b6d72d8f2e768.jpg'/> </a>\n <div><a href=\"/profile/Mikester\" title=\"Master Mikester\" class=\"rated-user user-orange\">Mikester</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 22:54\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158598\" href=\"?#comment-158598\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158598\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"13\"\r\n data-commentUserId=\"109566\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+13</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158598\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>elfus has some of the best rounds on Codeforces, and definitely the best editorials. Congratulations to you and Rares for the round !</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158598 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158598 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158598\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158599\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/iPs\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/144469/avatar/10358ae72910ceac.jpg'/> </a>\n <div><a href=\"/profile/iPs\" title=\"Expert iPs\" class=\"rated-user user-blue\">iPs</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 22:54\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158599\" href=\"?#comment-158599\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158599\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"33\"\r\n data-commentUserId=\"144469\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+33</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158599\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>best editorial I have ever seen in codeforces</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158599 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158599 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158599\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158600\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/bli0042\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/88584/avatar/51c3a9b55a3537fa.jpg'/> </a>\n <div><a href=\"/profile/bli0042\" title=\"Candidate Master bli0042\" class=\"rated-user user-violet\">bli0042</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 22:54\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158600\" href=\"?#comment-158600\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"158600\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"158600\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"88584\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158600\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For Div 2C, if A[i] = A[j] = 0 and we put i before j, won't j lose milk? Or am I misinterpreting the solution?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158600 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158600 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158600\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158601\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/aabs08\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/aabs08\" title=\"Expert aabs08\" class=\"rated-user user-blue\">aabs08</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 22:55\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158601\" href=\"?#comment-158601\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"158601\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"158601\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"9\"\r\n data-commentUserId=\"86699\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+9</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158601\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>One of the best editorials i came across in codeforces :D otherwise the editorial here are really very short and objective.</p><p>Every one here should write editorials like you :) !!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158601 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158601 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158601\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158607\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Xellos\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/69675/avatar/8526bcfc8e687b43.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/Xellos\" title=\"International Grandmaster Xellos\" class=\"rated-user user-red\">Xellos</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 23:03\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158607\" href=\"?#comment-158607\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"158607\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"158607\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"17\"\r\n data-commentUserId=\"69675\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+17</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158607\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Finally a tutorial worth upvoting!</p><p>I didn't really need to think about D. As soon as I saw the constraint on <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/986936bec272878d92f9c6fb0f0ce3c5b118cc0e.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />, I decided to try a DP on (position,sum) — it was a massive hint for me. Well, sometimes it just happens that there's a simple solution, which the author doesn't realize :D. Maybe this could be eliminated by some extensive "problem testing" by random capable people?</p><p>I guess I was also lucky in not trying to solve B. I solved in the order: A (because it's easy), C (because I like it), D (because it's easy) :D</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158607 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158607 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158607\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158610\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Mostafa_36a2\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/137637/avatar/28a01293a2b409.jpg'/> </a>\n <div><a href=\"/profile/Mostafa_36a2\" title=\"Specialist Mostafa_36a2\" class=\"rated-user user-cyan\">Mostafa_36a2</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 23:09\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158610\" href=\"?#comment-158610\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158610\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"-9\"\r\n data-commentUserId=\"137637\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-9</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158610\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I've found a very short solution for Div2 C , by zxz5759209</p> <pre><code>scanf("%d",&n);\n LL cnt=0,sum=0;\n for(int i=1;i<=n;i++)\n {\n scanf("%d",&x);\n cnt+=(LL)x;\n if(!x)sum+=cnt;\n }\n printf("%I64d\\n",sum);\n</code></pre></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158610 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158610 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158610\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158641\" commentParentId=\"158610\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Robert.One\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Robert.One\" title=\"Pupil Robert.One\" class=\"rated-user user-green\">Robert.One</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 01:27\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158641\" href=\"?#comment-158641\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-158610\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158641\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"150202\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158641\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I also had this solution and i got accepted but it took 1 hour to find it during the contest</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158641 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158641 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158641\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158612\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Darek_\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Darek_\" title=\"Specialist Darek_\" class=\"rated-user user-cyan\">Darek_</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 23:12\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158612\" href=\"?#comment-158612\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158612\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"152123\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158612\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks for an informative editorial.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158612 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158612 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158612\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158618\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Mostafa_36a2\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/137637/avatar/28a01293a2b409.jpg'/> </a>\n <div><a href=\"/profile/Mostafa_36a2\" title=\"Specialist Mostafa_36a2\" class=\"rated-user user-cyan\">Mostafa_36a2</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 23:25\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158618\" href=\"?#comment-158618\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"158618\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"158618\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"137637\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158618\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Unbelivable solution for Div2,B by Sick_Coder</p> <pre><code>cin >> n >> m >> k;\n cout << m * (m - 1) / 2 << "\\n";\n\n for (1, m, i)\n \tfor (i + 1, m, j)\n \t\tif (!k)\n \t\t\tcout << i << " " << j << "\\n";\n \t\telse\t\n \t\t\tcout << j << " " << i << "\\n";\n</code></pre></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158618 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158618 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158618\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158631\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mugurelionut\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/63702/avatar/45e4d5390c215090.jpg'/> </a>\n <div><a href=\"/profile/mugurelionut\" title=\"International Master mugurelionut\" class=\"rated-user user-orange\">mugurelionut</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 23:57\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158631\" href=\"?#comment-158631\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158631\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"63702\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158631\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>A very good editorial, indeed! (but please don't forget about Div1E) And the problems were really nice. But I think problem B was tougher than it should have been for its amount of points. I've read some comments saying that problem B had too weak pretests (because so many solutions failed the final system tests). I would have to say that my experience with problem B was the exact opposite. I coded two wrong solutions (which failed some pretest or another) before eventually finding and implementing the right solution. So I'd say that problem B had good pretests :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158631 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158631 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158631\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158635\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/MohammadFatafta\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/148405/avatar/4276577919b9713d.jpg'/> </a>\n <div><a href=\"/profile/MohammadFatafta\" title=\"Specialist MohammadFatafta\" class=\"rated-user user-cyan\">MohammadFatafta</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 00:11\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158635\" href=\"?#comment-158635\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158635\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"148405\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158635\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>now this is a real editorial!! thanks guys :D</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158635 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158635 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158635\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158636\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/matrix\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/matrix\" title=\"Master matrix\" class=\"rated-user user-orange\">matrix</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 00:15\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158636\" href=\"?#comment-158636\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"158636\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"158636\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"16572\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158636\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Hi,</p><p>Great and fast editorial with complete details. </p><p>Thanks very much.</p><p>Edit: I think there is a small typo: "It’s not hard to see that answer for a fixed (i1, j1) is left[i1][j1] * value[2 * j1 – sum_of_elements_from_i1]." I guess you meant count[2 * j1 – sum_of_elements_from_i1].</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158636 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158636 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158636\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158637\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Kyuubi\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/83590/avatar/b87432a652bb276.jpg'/> </a>\n <div><a href=\"/profile/Kyuubi\" title=\"Expert Kyuubi\" class=\"rated-user user-blue\">Kyuubi</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 00:18\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158637\" href=\"?#comment-158637\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158637\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"2\"\r\n data-commentUserId=\"83590\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+2</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158637\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Best Editorials I have seen on codeforces yet! :D</p><p>For Propagating tree, how do we keep track of alternating levels in the arrays we created using DFS ? </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158637 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158637 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158637\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158640\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/k_____k\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/60285/avatar/422359e1ae9d666c.jpg'/> </a>\n <div><a href=\"/profile/k_____k\" title=\"Expert k_____k\" class=\"rated-user user-blue\">k_____k</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 01:07\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158640\" href=\"?#comment-158640\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158640\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"2\"\r\n data-commentUserId=\"60285\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+2</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158640\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Best Editorials Ever ! #thanks to the authors, for posting alternative solutions of contestants also. Great start in 2014. #Looking Forward.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158640 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158640 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158640\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158658\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/sillycross\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/41652/avatar/58966d0c793c6394.jpg'/> </a>\n <div><a href=\"/profile/sillycross\" title=\"Grandmaster sillycross\" class=\"rated-user user-red\">sillycross</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 07:49\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158658\" href=\"?#comment-158658\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158658\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"9\"\r\n data-commentUserId=\"41652\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+9</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158658\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Div1 E can be solved in O(2^24*24) or O(2^24+2^12*n)..</p><p>O(2^24*24): dp[i][s] means the sum of all contributions of subset s where all digits are same as s except the last i digits.. </p><p>O(2^24+2^12*n): the length of word is only 3. We divide the 24 letters in half, calculate the answer for all first 12 letters and all last 12 letters and merge them with brute-force. This can be solved in O(2^24). Then we subtract the words that are counted twice: these words are words that have 2 letters in first half and 1 in second half, or 2 in second half and 1 in first half. Let's consider the first case: for each subset of first 12 letters we check each word whether it has exactly 2 letters in this half, if so, we can say all masks in another half that contains the third letter need to be subtracted by 1. This can be solved in 2^12*(2^12+n). Same algorithm can be used to solve the second case. Although this algorithm runs slower than O(2^24*24) bcuz of its larger constant... </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158658 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158658 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158658\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158663\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/VeniVidiVici\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/VeniVidiVici\" title=\"Candidate Master VeniVidiVici\" class=\"rated-user user-violet\">VeniVidiVici</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 09:39\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158663\" href=\"?#comment-158663\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158663\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"149163\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158663\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Very nice editorial! Disappointed in Div 2B though, really expected the "real" problem rather than just insertion sort but that's what you get for not reading carefully ;)</p><p>However, does anyone have an accepted solution that is "real" (e.g. finds the minimum number of operations necessary and prints such a solution)? I was close but my computer died during contest and I haven't tried so much since (of course you can do O((mn)^2) easily but this is way too slow, there should be a O(n*m^2) solution but again my computer was unable to operate). My approach was to make 2-D boolean array to check if a swap is necessary, but I'm not sure if order of operations will end up being a big problem.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158663 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158663 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158663\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158685\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/LegendaryGrandmaster\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/142091/avatar/a3a5a4b5c26ac419.jpg'/> </a>\n <div><a href=\"/profile/LegendaryGrandmaster\" title=\"Specialist LegendaryGrandmaster\" class=\"rated-user user-cyan\">LegendaryGrandmaster</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 14:34\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158685\" href=\"?#comment-158685\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158685\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"142091\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158685\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>One of the best codeforces editorials ever! Thanks!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158685 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158685 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158685\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158687\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/BENYAM1N\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/84938/avatar/d2ae2657d8898e38.jpg'/> </a>\n <div><a href=\"/profile/BENYAM1N\" title=\"Master BENYAM1N\" class=\"rated-user user-orange\">BENYAM1N</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 15:24\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158687\" href=\"?#comment-158687\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"158687\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"158687\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"84938\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158687\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks a lot. very good contest and good editorial too!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158687 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158687 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158687\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158689\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/JuanMata\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/82548/avatar/a7d69af7b441c6d7.jpg'/> </a>\n <div><a href=\"/profile/JuanMata\" title=\"Expert JuanMata\" class=\"rated-user user-blue\">JuanMata</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 15:47\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158689\" href=\"?#comment-158689\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158689\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"82548\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158689\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>this is one of the best editorials on CF ever!!!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158689 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158689 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158689\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158700\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Vicfred\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/76941/avatar/d067b7433ec39337.jpg'/> </a>\n <div><a href=\"/profile/Vicfred\" title=\"Pupil Vicfred\" class=\"rated-user user-green\">Vicfred</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 16:25\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158700\" href=\"?#comment-158700\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158700\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"11\"\r\n data-commentUserId=\"76941\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+11</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158700\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>The best editorial I've read in a while here, thanks.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158700 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158700 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158700\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158727\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/beecoder\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/beecoder\" title=\"Pupil beecoder\" class=\"rated-user user-green\">beecoder</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 21:13\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158727\" href=\"?#comment-158727\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158727\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"89551\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158727\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Hi, The way I print answers for 'Coder Problem' is as follows. This takes 124 ms. is there a way to print the answers faster ? </p> <pre><code> \tfor (int i = 0 ; i < number ; i ++ ) { \n \t\tfor (int k = 0 ; k < number ; k ++ ) { \n \t\t\tif (flag) {\n \t\t\t\tif ( k % 2 == 1) out.print('.');\n \t\t\t\tif( k% 2 == 0 ) out.print('C');\n \t\t\t} else {\n \t\t\tif ( k % 2 == 1) out.print('C');\n \t\t\tif( k% 2 == 0 ) out.print('.');\t\n \t\t\t}\n \t\t}\n \t\tif (flag) flag = false;\n \t\telse flag = true;\n \t\tout.print("\\n");\n \t}\n \n</code></pre></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158727 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158727 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158727\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158742\" commentParentId=\"158727\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Mostafa_36a2\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/137637/avatar/28a01293a2b409.jpg'/> </a>\n <div><a href=\"/profile/Mostafa_36a2\" title=\"Specialist Mostafa_36a2\" class=\"rated-user user-cyan\">Mostafa_36a2</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/22/2014 14:00\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158742\" href=\"?#comment-158742\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-158727\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158742\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"137637\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158742\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>As the line contains k characters , and every odd lines are identical , also the even ones,</p><p>you can build 2 strings [C.C.C.C] and [.C.C.C.] and print them alternately </p><p>[In my opinion Java is slow language any way ]</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158742 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158742 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158742\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158752\" commentParentId=\"158727\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/t_thirupathi\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/146179/avatar/98c28348196ce4ca.jpg'/> </a>\n <div><a href=\"/profile/t_thirupathi\" title=\"Specialist t_thirupathi\" class=\"rated-user user-cyan\">t_thirupathi</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/22/2014 18:19\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158752\" href=\"?#comment-158752\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-158727\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158752\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"146179\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158752\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Modulo operations are time consuming.</p><p>To check if a number <code>n</code> is odd, you could use <code>if (n & 1)</code></p> <pre><code>for (int i = 0; i < n; i++) {\n for (int j = 0; j < n; j++)\n if ((i + j) & 1)\n out.print('.');\n else \n out.print('C');\n out.print('\\n');\n}\n</code></pre></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158752 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158752 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158752\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158745\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/JuanMata\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/82548/avatar/a7d69af7b441c6d7.jpg'/> </a>\n <div><a href=\"/profile/JuanMata\" title=\"Expert JuanMata\" class=\"rated-user user-blue\">JuanMata</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/22/2014 14:49\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158745\" href=\"?#comment-158745\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"158745\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"158745\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"82548\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158745\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>i think there is a small bug in the <a href=\"http://pastie.org/8651824\">pastie link</a> u posted for the solution of Div1 C problem.</p><p>i submitted almost exact copy of it (<a href=\"/contest/383/submission/5769615\" title=\"Submission 5769615 by JuanMata\">5769615</a>), but got WA#6. then i found the bug, corrected it and resubmitted (<a href=\"/contest/383/submission/5769890\" title=\"Submission 5769890 by JuanMata\">5769890</a>) and got AC.</p><p>referring to my two submissions, corrections in line <strong>68</strong> (last statement of <strong>dfs</strong>) and line <strong>109</strong> (the second call to <strong>update</strong>).</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158745 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158745 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158745\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"615836\" commentParentId=\"158745\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/adityakr007\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/adityakr007\" title=\"Expert adityakr007\" class=\"rated-user user-blue\">adityakr007</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/05/2020 18:54\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-615836\" href=\"?#comment-615836\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-158745\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"615836\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"866209\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-615836\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can you explain what exactly have you done in your submission (<a href=\"/contest/383/submission/5769890\" title=\"Submission 5769890 by JuanMata\">5769890</a>) for this problem?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-615836 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-615836 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-615836\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"629531\" commentParentId=\"615836\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/JuanMata\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/82548/avatar/a7d69af7b441c6d7.jpg'/> </a>\n <div><a href=\"/profile/JuanMata\" title=\"Expert JuanMata\" class=\"rated-user user-blue\">JuanMata</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/25/2020 18:14\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-629531\" href=\"?#comment-629531\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-615836\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"629531\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"82548\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-629531\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>sorry bro i've forgotten ... that was over 6yrs ago now!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-629531 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-629531 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-629531\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158751\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/TempuX\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/30820/avatar/c50adc243ea4e2fa.jpg'/> </a>\n <div><a href=\"/profile/TempuX\" title=\"Specialist TempuX\" class=\"rated-user user-cyan\">TempuX</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/22/2014 17:07\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158751\" href=\"?#comment-158751\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158751\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"30820\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158751\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Hi, I tried to implement the Volcano problem in the way explained in the editorial but I'm getting TLE. Here is my code <a href=\"//codeforces.com/contest/384/submission/5770818\">submission</a> What am I doing wrong ? Thanks anyway.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158751 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158751 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158751\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158811\" commentParentId=\"158751\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/TempuX\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/30820/avatar/c50adc243ea4e2fa.jpg'/> </a>\n <div><a href=\"/profile/TempuX\" title=\"Specialist TempuX\" class=\"rated-user user-cyan\">TempuX</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/23/2014 17:29\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158811\" href=\"?#comment-158811\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-158751\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158811\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"30820\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158811\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Turns out my binary search is causing the problem and I don't see what is wrong with it... I would appreciate any ideas.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158811 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158811 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158811\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159025\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/bboy_drain\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/76710/avatar/e0feb3aa135911d4.jpg'/> </a>\n <div><a href=\"/profile/bboy_drain\" title=\"Expert bboy_drain\" class=\"rated-user user-blue\">bboy_drain</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/25/2014 01:34\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159025\" href=\"?#comment-159025\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159025\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"76710\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159025\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Wow! This really helped me a lot! Very detailed explanations!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159025 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159025 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159025\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159092\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/AlexandruValeanu\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/131651/avatar/1c7d989c45052941.jpg'/> </a>\n <div><a href=\"/profile/AlexandruValeanu\" title=\"Candidate Master AlexandruValeanu\" class=\"rated-user user-violet\">AlexandruValeanu</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/25/2014 21:27\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159092\" href=\"?#comment-159092\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159092\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"131651\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159092\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>It was by far your best round on Codeforces, <a class=\"rated-user user-blue\" href=\"/profile/fchirica\" title=\"Expert fchirica\">fchirica</a>. The problems were great, very different one from the other and some of them didn't require any algorithmic skills at all. Good job!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159092 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159092 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159092\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159261\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lawsonh\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/lawsonh\" title=\"Expert lawsonh\" class=\"rated-user user-blue\">lawsonh</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/28/2014 06:33\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159261\" href=\"?#comment-159261\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"159261\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"159261\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"55047\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159261\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>for div1 383C should end[5] = 7? edit: nvm drew the tree wrong</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159261 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159261 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159261\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159474\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/tiagonapoli\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/150060/avatar/6615fcab66b23361.jpg'/> </a>\n <div><a href=\"/profile/tiagonapoli\" title=\"Candidate Master tiagonapoli\" class=\"rated-user user-violet\">tiagonapoli</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/30/2014 22:28\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159474\" href=\"?#comment-159474\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159474\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"150060\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159474\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Great Editorial! Thanks so much, i've learned a lot!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159474 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159474 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159474\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159707\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lchf\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/60496/avatar/e9939e755252ec16.jpg'/> </a>\n <div><a href=\"/profile/lchf\" title=\"Candidate Master lchf\" class=\"rated-user user-violet\">lchf</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/02/2014 17:28\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159707\" href=\"?#comment-159707\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159707\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"60496\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159707\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Amazing solution by Endagorion.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159707 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159707 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159707\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"177400\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/sourabh912\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/57335/avatar/bf83b9340e3cbb17.jpg'/> </a>\n <div><a href=\"/profile/sourabh912\" title=\"Specialist sourabh912\" class=\"rated-user user-cyan\">sourabh912</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/12/2014 20:39\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-177400\" href=\"?#comment-177400\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"177400\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"57335\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-177400\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In Div 1C problem, I could not understand how it can be solved using single fenwick tree from the solution link in the editorial. Can anyone please help.</p><p>Thanks</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-177400 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-177400 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-177400\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"291157\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/l_Love_KFC\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/258117/avatar/bbaec3ce1613f5bd.jpg'/> </a>\n <div><a href=\"/profile/l_Love_KFC\" title=\"Expert l_Love_KFC\" class=\"rated-user user-blue\">l_Love_KFC</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Apr/29/2016 08:23\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-291157\" href=\"?#comment-291157\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"291157\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"258117\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-291157\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In Div.1 A I didn't catch the point that in 1st, quote : "If we put i before j, no additional cost will be added. Since j is in right of i and i only adds cost when it finds elements in left of i, j won’t be affected when processing i." Won't we lose milk if we put firstly i, in case of that j sees that and loses milk? Or am I misunderstanding the task? </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-291157 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-291157 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-291157\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"309434\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/haleyk100198\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/416324/avatar/f2d97d505af17e9d.jpg'/> </a>\n <div><a href=\"/profile/haleyk100198\" title=\"Candidate Master haleyk100198\" class=\"rated-user user-violet\">haleyk100198</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/11/2016 06:32\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-309434\" href=\"?#comment-309434\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"309434\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"416324\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-309434\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I wonder how the problem Div1C can be converted to a segment tree lazy propagation implementation question, for trees like (1-2 2-3 3-4 4-5 .... 9999-E4) how can we achieve O(log N) update time?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-309434 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-309434 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-309434\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"310847\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/my_new_handle\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/233736/avatar/24128c61b65e3262.jpg'/> </a>\n <div><a href=\"/profile/my_new_handle\" title=\"Candidate Master my_new_handle\" class=\"rated-user user-violet\">my_new_handle</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/20/2016 14:49\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-310847\" href=\"?#comment-310847\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"310847\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"233736\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-310847\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>а зачем в таске б массив он влияет как-то?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-310847 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-310847 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-310847\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"332763\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/rhezo\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/305605/avatar/aa59e9c2ec688c6a.jpg'/> </a>\n <div><a href=\"/profile/rhezo\" title=\"Candidate Master rhezo\" class=\"rated-user user-violet\">rhezo</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Dec/24/2016 07:56\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-332763\" href=\"?#comment-332763\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"332763\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"305605\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-332763\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I'm getting Runtime Error on test 44 in <a href=\"//codeforces.com/problemset/problem/383/C\">Propogating Tree</a>. </p><p>This is because of stack overflow right? That test has N = 2e5 and for a straight chain of nodes, I'll get a runtime error with a recursive DFS right? What to do in such cases? </p><p>I can write an iterative DFS, but I do HLD recursively too and I'm not quite sure if I can write an iterative HLD. </p><p>Can anyone tell me what to do in such cases? I'm assuming that I got the runtime error due to stackoverflow from DFS.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-332763 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-332763 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-332763\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"346070\" commentParentId=\"332763\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/yinanzhu\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/520731/avatar/d61a58bf5df54146.jpg'/> </a>\n <div><a href=\"/profile/yinanzhu\" title=\"Expert yinanzhu\" class=\"rated-user user-blue\">yinanzhu</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/26/2017 07:18\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-346070\" href=\"?#comment-346070\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-332763\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"346070\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"520731\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-346070\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I used recursive dfs and passed all test case. Test 44 cost 1.5 s</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-346070 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-346070 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-346070\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"387028\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/blue__legend\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/blue__legend\" title=\"Expert blue__legend\" class=\"rated-user user-blue\">blue__legend</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/23/2017 07:16\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-387028\" href=\"?#comment-387028\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"387028\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"284949\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-387028\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>How to solve DIV 1 C using one fenwick or segment tree. The code link given in editorial is not working.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-387028 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-387028 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-387028\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"757423\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Ausmosian\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Ausmosian\" title=\"Expert Ausmosian\" class=\"rated-user user-blue\">Ausmosian</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/05/2021 15:05\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-757423\" href=\"?#comment-757423\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"757423\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"727283\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-757423\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>[<a href=\"https://codeforces.com/contest/383/problem/C\">384E — Propagating tree</a>] Can also be solved using Square Root Decomposition. <a href=\"https://codeforces.com/contest/383/submission/106526543\">Submission</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-757423 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-757423 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-757423\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"838255\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/3hill\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1621900/avatar/478297db63bad207.jpg'/> </a>\n <div><a href=\"/profile/3hill\" title=\"Expert 3hill\" class=\"rated-user user-blue\">3hill</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/11/2021 17:02\">2 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-838255\" href=\"?#comment-838255\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"838255\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1621900\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-838255\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I am Getting MLE on TC-53<br />Can someone review my code and figure out the issue ,Thanks</p> <ul> <li><a href=\"https://codeforces.com/contest/383/problem/C\">Problem</a></li> <li><a href=\"https://codeforces.com/contest/383/submission/128510633\">My code</a></li> </ul></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-838255 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-838255 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-838255\">\r\n </ul>\r\n</div>\r\n <br/>\r\n\r\n<div id=\"editBox-10547\" style=\"width:50em;display:none;\">\r\n <div class=\"previewBody\" style=\"border: 1px solid #d4d4d4; margin-bottom: 0.5em; padding: 0.25em; display:none;\"> </div>\r\n <div style=\"width: 1px\"> </div>\r\n <div class=\"commentLocale\" style=\"position: relative; top: 0.5em;left:4px;display: none;\">\r\n <input type=\"radio\" name=\"locale\" value=\"en\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In English</span>\r\n <input style=\"margin-left:1em\" type=\"radio\" name=\"locale\" value=\"ru\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In Russian</span>\r\n </div>\r\n <textarea data-drafts-id=\"CommentReplyFrame\" class=\"wysiwyg\" name=\"editContent\" rows=\"20\" style=\"width:99%;\"></textarea>\r\n <div class=\"error error__content\"></div>\r\n <div style=\"text-align:center;\">\r\n <input type=\"button\" name=\"preview\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Preview\"/>\r\n <input type=\"button\" name=\"save\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Save\"/>\r\n </div>\r\n</div>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n\r\nvar firstPreview10547 = true;\r\nvar lastPreviewContent10547 = '';\r\n\r\nif (!window.moveCommentRevision) {\r\n moveCommentRevision = function(e, dir) {\r\n var p = e.parent();\r\n var revisionCount = parseInt(p.attr(\"revisionCount\"));\r\n var revision = parseInt(p.attr(\"revision\"));\r\n var next = revision + dir;\r\n var commentId = p.attr(\"commentId\");\r\n if (next >= 1 && next <= revisionCount) {\r\n $.post(\r\n \"/data/comment-data\",\r\n {action: \"revision\", commentId: commentId, revision: next},\r\n function(json) {\r\n if (json.success == \"true\") {\r\n var parentDiv = e;\r\n\r\n while (parentDiv !== null && (parentDiv[0].nodeName.toLowerCase() !== \"td\" || !parentDiv.hasClass(\"right\"))) {\r\n parentDiv = parentDiv.parent();\r\n }\r\n\r\n if (parentDiv === null) {\r\n return;\r\n }\r\n\r\n parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\").html(json.content);\r\n Codeforces.setupSpoilers(parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\"));\r\n p.attr(\"revision\", next);\r\n p.find(\"span.revision\").text(next);\r\n if (next == 1) {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"visible\");\r\n }\r\n if (next == revisionCount) {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"visible\");\r\n }\r\n\r\n window.updateTypography();\r\n MathJax.Hub.Typeset();\r\n } else {\r\n alert(e.error);\r\n }\r\n },\r\n \"json\"\r\n );\r\n }\r\n };\r\n}\r\n\r\n$(\"div[commentableId=10547] a.leftRevision\").click(function () {\r\n window.moveCommentRevision($(this), -1);\r\n return false;\r\n});\r\n\r\n$(\"div[commentableId=10547] a.rightRevision\").click(function () {\r\n window.moveCommentRevision($(this), +1);\r\n return false;\r\n});\r\n\r\n\r\n\r\n });\n </script>\n\r\n\r\n <script src=\"//codeforces.org/s/81027/js/swfobject-2.2.min.js\" type=\"text/javascript\"></script>\n <script src=\"//codeforces.org/s/81027/js/ftaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n if (window.evercookie) {\n var ec = new evercookie({\n history: false,\n silverlight: false,\n baseurl: '',\n asseturi: '/assets',\n phpuri: '/2fdcd78',\n pngPath: '/eps',\n etagPath: '/ees',\n cachePath: '/ecs'\n });\n\n var randomNumber = function () {\n return Math.random().toString(36).substr(2);\n };\n\n var randomToken = function () {\n return (randomNumber() + randomNumber()).substring(0, 18);\n };\n\n window._ftaa = \"\";\n\n ec.get(\"70a7c28f3de\", function (value) {\n window._ftaa = value;\n if (!window._ftaa) {\n window._ftaa = randomToken();\n ec.set(\"70a7c28f3de\", window._ftaa);\n }\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n } else {\n window._ftaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\n <script src=\"//codeforces.org/s/81027/js/bfaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n var fpCallback = function() {\n Fingerprint2.get({}, function(components) {\n window._bfaa = Fingerprint2.x64hash128(components.map(function (pair) { return pair.value }).join(), 31);\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n };\n if (typeof Fingerprint2 !== 'undefined') {\n if (window.requestIdleCallback) {\n requestIdleCallback(fpCallback)\n } else {\n setTimeout(fpCallback, 500)\n }\n } else {\n window._bfaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"a.new-root-comment\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n\r\n $(\".comment-table .reply a\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".vote-for-comment\").mouseover(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").mouseout(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").click(function () {\r\n var vote = $(this);\r\n var commentId = $(this).parent().attr(\"commentid\");\r\n var commentRating = $(this).parent().attr(\"data-commentRating\");\r\n var direction = $(this).attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n $.post(\"/data/comment/vote\", {commentId: commentId, _tta: Codeforces.tta(), vote: direction, commentRating: commentRating}, function(data) {\r\n if (direction != 0 && !ownComment && data[\"success\"] == \"true\") {\r\n vote.parent().find(\".vote-for-comment\").attr(\"voteDirection\", 0);\r\n if (direction == 1)\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n else {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.closest(\".CommentVoteFrame\").find(\".ComplaintFrame\").css(\"display\", \"inline-block\");\r\n }\r\n vote.find(\"img\").attr(\"popacity\", \"1.0\");\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n vote.parent().find(\".commentRating\").html(data[\"commentRating\"]);\r\n }\r\n Codeforces.showMessage(data[\"message\"]);\r\n }, \"json\");\r\n return false;\r\n });\r\n\r\n $(\".negative-comment-vote\").closest(\".comment-table\").addClass(\"comment-bad\");\r\n\r\n $(\".troll-comment-vote\").closest(\".comment\").css(\"display\", \"none\");\r\n\r\n $(\".too-negative-comment-vote\").closest(\".comment-table\").each(function () {\r\n var e = $(this);\r\n e.addClass(\"comment-too-bad\");\r\n var commentId = e.attr(\"commentId\");\r\n $(\"<div class='bad-comment-replacement ttypography'>The comment is hidden because of too negative feedback, click <a href=# class=show-bad-comment-link>here</a> to view it</div>\").appendTo(\r\n e.find(\".right\")\r\n );\r\n e.find(\".comment-content\").hide();\r\n e.find(\".show-bad-comment-link\").click(function () {\r\n e.find(\".comment-content\").show();\r\n e.find(\".bad-comment-replacement\").hide();\r\n return false;\r\n });\r\n });\r\n });\n </script>\n </div>\r\n\r\n <style type=\"text/css\">\r\n .new-comments-box {\r\n padding: 0.5em;\r\n width: 22px;\r\n font-size: 1.3rem;\r\n font-weight: bold !important;\r\n\r\n position: fixed;\r\n top: 40%;\r\n right: 0;\r\n opacity: 0.2;\r\n color: white;\r\n text-align: center;\r\n\r\n border: 1px solid #222;\r\n background-color: #888 !important;\r\n border-radius: 3px;\r\n -moz-border-radius: 3px;\r\n -webkit-border-radius: 3px;\r\n }\r\n\r\n .new-comments-box:hover {\r\n opacity: 1;\r\n }\r\n\r\n .new-comments-box .dir:hover {\r\n background: #3B5998 !important;\r\n cursor: pointer;\r\n }\r\n </style>\r\n\r\n <div class=\"new-comments-box\" data-position=\"outside\" data-index=\"-1\" style=\"display: none;\">\r\n <div class=\"up dir\" title=\"Ctrl+Up\">↑<hr/>\r\n </div>\r\n <div class=\"info\" title=\"New comments\"></div>\r\n <div class=\"down dir\" title=\"Ctrl+Down\">\r\n <hr/>↓\r\n </div>\r\n </div>\r\n\r\n <script>\r\n $(\".show-archived-checkbox\").change(function () {\r\n const checked = $(this).is(\":checked\");\r\n $.post(\"/data/comment-data\", {action: \"setShowArchived\", checked}, function (json) {\r\n if (json[\"success\"] !== \"true\") {\r\n alert(json[\"error\"]);\r\n } else {\r\n if (checked) {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are now displayed\")\r\n } else {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are no longer displayed\")\r\n }\r\n }\r\n });\r\n return false;\r\n });\r\n\r\n function gotoComment(direction) {\r\n var box = $(\".new-comments-box\");\r\n var index = parseInt(box.attr(\"data-index\"));\r\n if (index == -1)\r\n index = 0;\r\n else\r\n index = Math.max(0, Math.min(parseInt(box.find(\".info\").text()) - 1, index + direction));\r\n box.attr(\"data-index\", index);\r\n var comment = $($(\".comment .highlight-blue[commentId]\").get(index));\r\n $('html, body').animate({\r\n 'scrollTop': Math.max(0, comment.offset().top - ($(window).height() - comment.height()) / 2)\r\n });\r\n return false;\r\n }\r\n\r\n $(\".new-comments-box .down\").click(function () {\r\n return gotoComment(1);\r\n });\r\n\r\n $(\".new-comments-box .up\").click(function () {\r\n return gotoComment(-1);\r\n });\r\n\r\n $(document).keydown(function (e) {\r\n var code = (e.keyCode ? e.keyCode : e.which);\r\n if (e.ctrlKey) {\r\n if (code == 38 || code == 40) {\r\n gotoComment(code - 39);\r\n }\r\n }\r\n });\r\n\r\n var newCommentCount = $(\".comment .highlight-blue[commentId]\").length;\r\n if (newCommentCount > 0) {\r\n $(\".new-comments-box .info\").text(newCommentCount);\r\n $(\".new-comments-box\").show();\r\n }\r\n\r\n $('table.comment-table').mouseenter(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").addClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n\r\n $('table.comment-table').mouseleave(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").removeClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n </script>\r\n\r\n\r\n\r\n <script>\r\n function adjustTopicComplainFrames() {\r\n let topicIds = [];\r\n\r\n $(\".has-topic-id\").each(function () {\r\n const $this = $(this);\r\n const topicId = $this.attr(\"topicId\");\r\n if (topicId) {\r\n topicIds.push(topicId);\r\n }\r\n });\r\n\r\n $.post(\"/data/topics\", {\r\n action: \"findComplainableTopicIds\",\r\n topicIds: topicIds.join(\",\")\r\n }, function (json) {\r\n if (json[\"success\"] === \"true\") {\r\n for (const topicId of json[\"complainableTopicIds\"].split(\",\")) {\r\n $(\".has-topic-id[topicId=\" + topicId + \"]\").each(function () {\r\n $(this).find(\".meta .ComplaintFrame\").css(\"display\", \"inline-block\");\r\n });\r\n }\r\n }\r\n }, \"json\");\r\n }\r\n\r\n $(function () {\r\n adjustTopicComplainFrames();\r\n })\r\n </script>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-10531\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 10531, _tta: Codeforces.tta(), topicRevisionId: 36233, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-10531\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 10531, _tta: Codeforces.tta(), topicRevisionId: 36233, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n </div>\r\n </div>\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 22:13:02</span> (h1).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/81027/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/81027/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/81027/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/81027/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-81027.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'81287584a8369d92',t:'MTY5NjcwNTk4Mi42NDcwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"}}},{"rowIdx":1941,"cells":{"problem_id":{"kind":"string","value":"384C"},"contest":{"kind":"string","value":"384"},"problem":{"kind":"string","value":"C"},"lang":{"kind":"string","value":"en"},"problem_title":{"kind":"string","value":"C. Milking cows"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">C. Milking cows</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Iahub helps his grandfather at the farm. Today he must milk the cows. There are <span class=\"tex-span\"><i>n</i></span> cows sitting in a row, numbered from <span class=\"tex-span\">1</span> to <span class=\"tex-span\"><i>n</i></span> from left to right. Each cow is either facing to the left or facing to the right. When Iahub milks a cow, all the cows that see the current cow get scared and lose one unit of the quantity of milk that they can give. A cow facing left sees all the cows with lower indices than her index, and a cow facing right sees all the cows with higher indices than her index. A cow that got scared once can get scared again (and lose one more unit of milk). A cow that has been milked once cannot get scared and lose any more milk. You can assume that a cow never loses all the milk she can give (a cow gives an infinitely amount of milk).</p><p>Iahub can decide the order in which he milks the cows. But he must milk each cow exactly once. Iahub wants to lose as little milk as possible. Print the minimum amount of milk that is lost.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains an integer <span class=\"tex-span\"><i>n</i></span> <span class=\"tex-span\">(1 ≤ <i>n</i> ≤ 200000)</span>. The second line contains <span class=\"tex-span\"><i>n</i></span> integers <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub></span>, <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">2</sub></span>, ..., <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>n</i></sub></span>, where <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> is <span class=\"tex-span\">0</span> if the cow number <span class=\"tex-span\"><i>i</i></span> is facing left, and <span class=\"tex-span\">1</span> if it is facing right.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print a single integer, the minimum amount of lost milk.</p><p>Please, do not write the <span class=\"tex-font-style-tt\">%lld</span> specifier to read or write 64-bit integers in С++. It is preferred to use the <span class=\"tex-font-style-tt\">cin</span>, <span class=\"tex-font-style-tt\">cout</span> streams or the <span class=\"tex-font-style-tt\">%I64d</span> specifier.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>4<br/>0 0 1 0<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1</pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>5<br/>1 0 1 0 1<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>3</pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>In the first sample Iahub milks the cows in the following order: cow <span class=\"tex-span\">3</span>, cow <span class=\"tex-span\">4</span>, cow <span class=\"tex-span\">2</span>, cow <span class=\"tex-span\">1</span>. When he milks cow <span class=\"tex-span\">3</span>, cow <span class=\"tex-span\">4</span> loses <span class=\"tex-span\">1</span> unit of milk. After that, no more milk is lost.</p></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"10b5ff9f369810db961993cd7774bec2\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - C - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"2080925ccc752dc6d7cc9e06390b1986ca0eae39\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - C - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/73366/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/73366/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/73366/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/73366/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/73366/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/73366/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/73366/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/73366/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/73366/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/73366/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/73366/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/73366/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/73366/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/73366/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/sidebar-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/a037fe51637846d9c7c725713cd840ea/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='10b5ff9f369810db961993cd7774bec2'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/73366/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/73366/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fcontest%2F384%2Fproblem%2FC%3Flocale%3Den\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"current\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='10b5ff9f369810db961993cd7774bec2'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:100%;\"><a style=\"color: black\" href=\"/contest/384\">Codeforces Round 225 (Div. 2)</a></th>\n </tr>\n <tr>\n <td class=\"left bottom\" colspan=\"1\"><span class=\"contest-state-phase\">Finished</span></td>\n </tr>\n </tbody>\n </table>\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Practice?\n <div class=\"top-links\">\n </div>\n </div>\n<div>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Want to solve the contest problems after the official contest ends? Just register for practice and you will be able to submit solutions.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"\" method=\"post\"><input type='hidden' name='csrf_token' value='10b5ff9f369810db961993cd7774bec2'/>\r\n <input type=\"hidden\" name=\"action\" value=\"registerForPractice\"/>\r\n <input type=\"submit\" name=\"submit\" value=\"Register for practice\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div> \r\n</div>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox ContestVirtualFrame borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Virtual participation <i class=\"sidebar-caption-icon las la-angle-down\"></i>\r\n\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\" \"\r\n\r\n data-page-url=\"/data/sidebarFrames\"\r\n\r\n>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests.\n\nIf you've seen these problems, a virtual contest is not for you - solve these problems in the archive.\n\nIf you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.\n\nNever use someone else's code, read the tutorials or communicate with other person during a virtual contest.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"/contest/384/virtual\" method=\"get\">\r\n <input type=\"submit\" name=\"submit\" value=\"Start virtual contest\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div>\r\n</div>\r\n <script>\r\n $(function () {\r\n $(\".ContestVirtualFrame .sidebar-caption-icon\").click(function() {\r\n $(this).toggleClass(\"la-angle-down la-angle-right\");\r\n const $target = $(this).parent().next();\r\n $target.toggle();\r\n const dataPageUrl = $target.attr(\"data-page-url\");\r\n const collapsed = $(this).hasClass(\"la-angle-right\");\r\n const params = {\r\n action: \"setCollapsed\",\r\n sidebarFrameSimpleClassName: \"ContestVirtualFrame\",\r\n collapsed\r\n };\r\n $.each($target[0].attributes, function(i, a) {\r\n const name = a.name;\r\n if (name.startsWith(\"data-extra-key-\")) {\r\n const key = a.value;\r\n const keyIndex = parseInt(name.substring(\"data-extra-key-\".length));\r\n const value = $target.attr(\"data-extra-value-\" + keyIndex);\r\n params[key] = value;\r\n }\r\n });\r\n $.post(dataPageUrl, params, function (result) {\r\n if (result[\"success\"] !== \"true\") {\r\n Codeforces.showMessage(\"Failed to save collapsed state.\");\r\n }\r\n }, \"json\");\r\n return false;\r\n });\r\n })\r\n </script>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Problem tags\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Greedy algorithms\">\r\n greedy\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Difficulty\">\r\n *1600\r\n</span>\r\n </div>\n <div style=\"clear:both;text-align:right;font-size:1.1rem;\">\r\n <span title=\"Please login into the Codeforces\" class=\"notice\">No tag edit access</span>\r\n </div>\r\n</div>\r\n </div>\n\r\n<form id=\"addTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='10b5ff9f369810db961993cd7774bec2'/>\r\n <input name=\"action\" type=\"hidden\" value=\"addTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"5719\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<form id=\"removeTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='10b5ff9f369810db961993cd7774bec2'/>\r\n <input name=\"action\" type=\"hidden\" value=\"removeTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"5719\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<script type=\"text/javascript\">\r\n $(\".tag-box img\").click(function () {\r\n var tagName = $(this).attr(\"value\");\r\n Codeforces.confirm(\"Are you sure you want to remove this tag?\", function () {\r\n $(\"#removeTagForm input[name=tagName]\").val(tagName);\r\n $(\"#removeTagForm\").submit();\r\n }, function () {\r\n }, \"Yes\", \"No\");\r\n });\r\n\r\n $(\"#addTagLink\").click(function () {\r\n $(this).hide();\r\n $(\"#addTagLabel\").show();\r\n return false;\r\n });\r\n\r\n $(\"#addTagSelect\").change(function () {\r\n var tagName = $(this).val();\r\n if (tagName === \"\") {\r\n $(\"#addTagLabel\").hide();\r\n $(\"#addTagLink\").show();\r\n } else {\r\n $(\"#addTagForm input[name=tagName]\").val(tagName);\r\n $(\"#addTagForm\").submit();\r\n }\r\n });\r\n</script>\r\n\r\n<style type=\"text/css\">\r\n#new-resource-form tr td {\r\npadding-top: 0.5em;\r\n}\r\n#new-resource-form input:not([type=\"submit\"]) {\r\nfont-size: 0.8em;\r\n}\r\n#new-resource-form select {\r\nfont-size: 0.8em;\r\n}\r\n.new-resource-error {\r\nfont-size: 0.8em;\r\n}\r\n.resource-locale {\r\ncolor: #666;\r\nfont-family: Consolas, \"Andale Mono WT\", \"Andale Mono\", \"Lucida Console\", \"Lucida Sans Typewriter\", \"DejaVu Sans Mono\", \"Bitstream Vera Sans Mono\", \"Liberation Mono\", \"Nimbus Mono L\", Monaco, \"Courier New\", Courier, monospace;\r\n}\r\n</style>\r\n<div class=\"roundbox sidebox sidebar-menu borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Contest materials\n<div class=\"top-links\">\n</div>\n</div>\n<ul>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/10448\" title=\"Codeforces Round #225\" target=\"_blank\">Codeforces Round #225</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"2168:2169\" resourceName=\"Announcement\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/10476\" title=\"Codeforces Round #225 — Editorial\" target=\"_blank\">Tutorial <span class=\"resource-locale\">(en)</span></a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"2173\" resourceName=\"Codeforces Round #225 — Editorial\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n</ul>\r\n</div></div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li class=\"current selectedLava\"><a\r\n href=\"/contest/384\">Problems</a></li>\r\n <li><a\r\n href=\"/contest/384/submit\">Submit Code</a></li>\r\n <li><a\r\n href=\"/contest/384/my\">My Submissions</a></li>\r\n <li><a\r\n href=\"/contest/384/status\">Status</a></li>\r\n <li><a\r\n href=\"/contest/384/hacks\">Hacks</a></li>\r\n <li><a\r\n href=\"/contest/384/room/1\">Room</a></li>\r\n <li><a\r\n href=\"/contest/384/standings\">Standings</a></li>\r\n <li><a\r\n href=\"/contest/384/customtest\">Custom Invocation</a></li>\r\n</ul>\r\n</div>\n\r\n <style>\r\n #facebox .content:has(.diff-popup) {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n }\r\n\r\n .testCaseMarker {\r\n position: absolute;\r\n font-weight: bold;\r\n font-size: 1rem;\r\n }\r\n\r\n .diff-popup {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n display: none;\r\n overflow: auto;\r\n }\r\n\r\n .input-output-copier {\r\n font-size: 1.2rem;\r\n float: right;\r\n color: #888 !important;\r\n cursor: pointer;\r\n border: 1px solid rgb(185, 185, 185);\r\n padding: 3px;\r\n margin: 1px;\r\n line-height: 1.1rem;\r\n text-transform: none;\r\n }\r\n\r\n .input-output-copier:hover {\r\n background-color: #def;\r\n }\r\n\r\n .test-explanation textarea {\r\n width: 100%;\r\n height: 1.5em;\r\n }\r\n\r\n .pending-submission-message {\r\n color: darkorange !important;\r\n }\r\n </style>\r\n <script>\r\n const OPENING_SPACE = String.fromCharCode(1001);\r\n const CLOSING_SPACE = String.fromCharCode(1002);\r\n\r\n const nodeToText = function (node, pre) {\r\n let result = [];\r\n\r\n if (node.tagName === \"SCRIPT\" || node.tagName === \"math\"\r\n || (node.classList && node.classList.contains(\"input-output-copier\")))\r\n return [];\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(OPENING_SPACE);\r\n }\r\n\r\n if (node.nodeType === Node.TEXT_NODE) {\r\n let s = node.textContent;\r\n if (!pre) {\r\n s = s.replace(/\\s+/g, \" \");\r\n }\r\n if (s.length > 0) {\r\n result.push(s);\r\n }\r\n }\r\n\r\n if (pre && node.tagName === \"BR\") {\r\n result.push(\"\\n\");\r\n }\r\n\r\n node.childNodes.forEach(function (child) {\r\n result.push(nodeToText(child, node.tagName === \"PRE\").join(\"\"));\r\n });\r\n\r\n if (node.tagName === \"DIV\"\r\n || node.tagName === \"P\"\r\n || node.tagName === \"PRE\"\r\n || node.tagName === \"UL\"\r\n || node.tagName === \"LI\"\r\n ) {\r\n result.push(\"\\n\");\r\n }\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(CLOSING_SPACE);\r\n }\r\n\r\n return result;\r\n }\r\n\r\n const isSpecial = function (c) {\r\n return c === ',' || c === '.' || c === ';' || c === ')' || c === ' ';\r\n }\r\n\r\n const convertStatementToText = function(statmentNode) {\r\n const text = nodeToText(statmentNode, false).join(\"\").replace(/ +/g, \" \").replace(/\\n\\n+/g, \"\\n\\n\");\r\n let result = [];\r\n for (let i = 0; i < text.length; i++) {\r\n const c = text.charAt(i);\r\n if (c === OPENING_SPACE) {\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"C\" data-uuid=\"ps_a42389bb7ae51ea5ed8f5ef731dc9b7e7787d5af\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">C. Milking cows</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Iahub helps his grandfather at the farm. Today he must milk the cows. There are <span class=\"tex-span\"><i>n</i></span> cows sitting in a row, numbered from <span class=\"tex-span\">1</span> to <span class=\"tex-span\"><i>n</i></span> from left to right. Each cow is either facing to the left or facing to the right. When Iahub milks a cow, all the cows that see the current cow get scared and lose one unit of the quantity of milk that they can give. A cow facing left sees all the cows with lower indices than her index, and a cow facing right sees all the cows with higher indices than her index. A cow that got scared once can get scared again (and lose one more unit of milk). A cow that has been milked once cannot get scared and lose any more milk. You can assume that a cow never loses all the milk she can give (a cow gives an infinitely amount of milk).</p><p>Iahub can decide the order in which he milks the cows. But he must milk each cow exactly once. Iahub wants to lose as little milk as possible. Print the minimum amount of milk that is lost.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains an integer <span class=\"tex-span\"><i>n</i></span> <span class=\"tex-span\">(1 ≤ <i>n</i> ≤ 200000)</span>. The second line contains <span class=\"tex-span\"><i>n</i></span> integers <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub></span>, <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">2</sub></span>, ..., <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>n</i></sub></span>, where <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> is <span class=\"tex-span\">0</span> if the cow number <span class=\"tex-span\"><i>i</i></span> is facing left, and <span class=\"tex-span\">1</span> if it is facing right.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print a single integer, the minimum amount of lost milk.</p><p>Please, do not write the <span class=\"tex-font-style-tt\">%lld</span> specifier to read or write 64-bit integers in С++. It is preferred to use the <span class=\"tex-font-style-tt\">cin</span>, <span class=\"tex-font-style-tt\">cout</span> streams or the <span class=\"tex-font-style-tt\">%I64d</span> specifier.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>4<br />0 0 1 0<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1</pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>5<br />1 0 1 0 1<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>3</pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>In the first sample Iahub milks the cows in the following order: cow <span class=\"tex-span\">3</span>, cow <span class=\"tex-span\">4</span>, cow <span class=\"tex-span\">2</span>, cow <span class=\"tex-span\">1</span>. When he milks cow <span class=\"tex-span\">3</span>, cow <span class=\"tex-span\">4</span> loses <span class=\"tex-span\">1</span> unit of milk. After that, no more milk is lost.</p></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=C]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== statementText) {\r\n $problem.find(\".diff-notifier\").show();\r\n\r\n $problem.find(\".diff-notifier-close\").click(function() {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n $problem.find(\".diff-notifier\").hide();\r\n });\r\n\r\n $problem.find(\"a.view-changes\").click(function() {\r\n $.post(\"/data/diff\", {action: \"getDiff\", a: previousStatementText, b: statementText}, function (result) {\r\n if (result[\"success\"] === \"true\") {\r\n Codeforces.facebox(\".diff-popup\", \"//codeforces.org/s/73366\");\r\n $(\"#facebox .diff-popup\").html(result[\"diff\"]);\r\n }\r\n }, \"json\");\r\n });\r\n }\r\n } else {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n }\r\n });\r\n });\r\n </script>\r\n\r\n\r\n<script type=\"text/javascript\">\r\n $(document).ready(function () {\r\n window.changedTests = new Set();\r\n\r\n function endsWith(string, suffix) {\r\n return string.indexOf(suffix, string.length - suffix.length) !== -1;\r\n }\r\n\r\n const inputFileDiv = $(\"div.input-file\");\r\n const inputFile = inputFileDiv.text();\r\n const outputFileDiv = $(\"div.output-file\");\r\n const outputFile = outputFileDiv.text();\r\n\r\n\r\n if (!endsWith(inputFile, \"standard input\")\r\n && !endsWith(inputFile, \"standard input\")) {\r\n inputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n if (!endsWith(outputFile, \"standard output\")\r\n && !endsWith(outputFile, \"standard output\")) {\r\n outputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n const titleDiv = $(\"div.header div.title\");\r\n\r\n\r\n\r\n String.prototype.replaceAll = function (search, replace) {\r\n return this.split(search).join(replace);\r\n };\r\n\r\n $(\".sample-test .title\").each(function () {\r\n const preId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n const cpyId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n\r\n $(this).parent().find(\"pre\").attr(\"id\", preId);\r\n const $copy = $(\"<div title='Copy' data-clipboard-target='#\" + preId + \"' id='\" + cpyId + \"' class='input-output-copier'>Copy</div>\");\r\n $(this).append($copy);\r\n\r\n const clipboard = new Clipboard('#' + cpyId, {\r\n text: function (trigger) {\r\n const pre = document.querySelector('#' + preId);\r\n const lines = pre.querySelectorAll(\".test-example-line\");\r\n return Codeforces.filterClipboardText(pre.innerText, lines.length);\r\n }\r\n });\r\n\r\n const isInput = $(this).parent().hasClass(\"input\");\r\n\r\n clipboard.on('success', function (e) {\r\n if (isInput) {\r\n Codeforces.showMessage(\"The example input has been copied into the clipboard\");\r\n } else {\r\n Codeforces.showMessage(\"The example output has been copied into the clipboard\");\r\n }\r\n e.clearSelection();\r\n });\r\n });\r\n\r\n $(\".test-form-item input\").change(function () {\r\n addPendingSubmissionMessage($($(this).closest(\"form\")), \"You changed the answer, do not forget to submit it if you want to save the changes\");\r\n const index = $(this).closest(\".problemindexholder\").attr(\"problemindex\");\r\n let test = \"\";\r\n $(this).closest(\"form input\").each(function () {\r\n const test_ = $(this).attr(\"name\");\r\n if (test_ && test_.substring(0, 4) === \"test\") {\r\n test = test_;\r\n }\r\n });\r\n if (index.length > 0 && test.length > 0) {\r\n const indexTest = index + \"::\" + test;\r\n window.changedTests.add(indexTest);\r\n }\r\n });\r\n\r\n $(window).on('beforeunload', function () {\r\n if (window.changedTests.size > 0) {\r\n return 'Dialog text here';\r\n }\r\n });\r\n\r\n autosize($('.test-explanation textarea'));\r\n\r\n $(\".test-example-line\").hover(function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n let top = 1E20;\r\n let left = 1E20;\r\n let problem = $(this).closest(\".problemindexholder\");\r\n $(this).closest(\".input\").find(\".\" + clazz).css(\"background-color\", \"#FFFDE7\").each(function() {\r\n top = Math.min(top, $(this).offset().top);\r\n left = Math.min(left, $(this).offset().left);\r\n });\r\n let testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n if (testCaseMarker.length === 0) {\r\n const html = \"<div class=\\\"testCaseMarker testCaseMarker_\" + end + \" notice\\\"></div>\";\r\n problem.append($(html));\r\n testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n }\r\n if (testCaseMarker) {\r\n testCaseMarker.show()\r\n .offset({top, left: left - 20})\r\n .text(end);\r\n }\r\n }\r\n }\r\n });\r\n }, function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n $(\".\" + clazz).css(\"background-color\", \"\");\r\n $(this).closest(\".problemindexholder\").find(\".testCaseMarker_\" + end).hide();\r\n }\r\n }\r\n });\r\n });\r\n\r\n });\r\n</script>\r\n\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 05:38:06</span> (j3).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/73366/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/73366/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/73366/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/73366/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-73366.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'8122c41b2f3816e8',t:'MTY5NjY0NjI4Ni42MzcwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"},"long_tags":{"kind":"string","value":"[\"Greedy algorithms\"]"},"short_tags":{"kind":"string","value":"[\"greedy\", \"*1600\"]"},"tutorial_link":{"kind":"string","value":"https://codeforces.com/blog/entry/10476"},"tutorial_page":{"kind":"string","value":"\r\n\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"4f4c31ed5807bbee2a02378cf0944c06\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"h1\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Codeforces Round #225 — Editorial - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n \n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Codeforces Round #225 — Editorial - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/81027/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/81027/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/81027/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/81027/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/81027/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/81027/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/81027/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/81027/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/81027/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/81027/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/81027/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/81027/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/81027/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/81027/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/573cedc6b04c15481941f418269f4057/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='4f4c31ed5807bbee2a02378cf0944c06'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/81027/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fblog%2Fentry%2F10476\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='4f4c31ed5807bbee2a02378cf0944c06'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Pay attention\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n <div style=\"text-align:center;border-bottom: 1px solid rgb(185, 185, 185);margin:0 -0.5em 0.5em -0.5em;padding: 0 1em 0.5em 1em;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 1, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:51:58</span><br/><a href=\"/contestRegistration/1876\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n <div style=\"text-align:center;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 2, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:51:58</span><br/><a href=\"/contestRegistration/1877\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n\r\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div>\r\n\r\n\n <div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\n\r\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='4f4c31ed5807bbee2a02378cf0944c06'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n </label>\r\n </div>\r\n <div style=\"padding: 0 1em 1em 1em;text-align:right;\">\r\n <input style=\"height:1.65em;padding:0 0.75em;\" type=\"submit\" value=\"Find\"/>\r\n </div>\r\n </form>\r\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".handleBox\").autocomplete(\"/data/handles\", {\r\n delay: 200,\r\n width: 200,\r\n selectFirst: false,\r\n matchContains: true,\r\n minChars: 3\r\n });\r\n $(\".handleForm\").attr(\"autocomplete\", \"off\").submit(function () {\r\n var link = \"/profile/userHandle\".replace(\r\n \"userHandle\", $(this).find(\".handleBox\").val()\r\n );\r\n window.location = link;\r\n return false;\r\n });\r\n });\n </script>\n\r\n\r\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Recent actions\n <div class=\"top-links\">\n </div>\n </div>\n <div class=\"recent-actions\">\r\n <ul>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/121073\">Meta Hacker Cup 2023 Round 1</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/.Danet\" title=\"Expert .Danet\" class=\"rated-user user-blue\">.Danet</a> →\r\n <a href=\"/blog/entry/121172\">[TLE on pretest1]</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\" class=\"rated-user user-red\">Pyqe</a> →\r\n <a href=\"/blog/entry/121025\">Codeforces Round #902 (Div. 1, Div. 2, based on COMPFEST 15 — Final Round)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pranshu_Pandya\" title=\"Specialist Pranshu_Pandya\" class=\"rated-user user-cyan\">Pranshu_Pandya</a> →\r\n <a href=\"/blog/entry/121171\">An Interesting Tree Problem</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/sszcdjr\" title=\"Master sszcdjr\" class=\"rated-user user-orange\">sszcdjr</a> →\r\n <a href=\"/blog/entry/119859\">Codeforces Round 896 (Div. 1, Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/119880\">It's Happening! Meta Hacker Cup 2023 Schedule</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/DaviddeGea1\" title=\"Expert DaviddeGea1\" class=\"rated-user user-blue\">DaviddeGea1</a> →\r\n <a href=\"/blog/entry/70917\">Number of ways of dividing an array into 2 parts such that sum of each part is > k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bekh\" title=\"Master Bekh\" class=\"rated-user user-orange\">Bekh</a> →\r\n <a href=\"/blog/entry/74245\">Questions and doubts regarding Aliens DP trick</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a> →\r\n <a href=\"/blog/entry/8192\">Codeforces Round #190 — Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/hocky\" title=\"Candidate Master hocky\" class=\"rated-user user-violet\">hocky</a> →\r\n <a href=\"/blog/entry/95323\">FBHC wuining uw Day? Incwease uw stacc size! (ㅅ´ ˘ `)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/liouzhou_101\" title=\"International Master liouzhou_101\" class=\"rated-user user-orange\">liouzhou_101</a> →\r\n <a href=\"/blog/entry/87598\">Editorial of Codeforces Round #700</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/yeon_gist\" title=\"Newbie yeon_gist\" class=\"rated-user user-gray\">yeon_gist</a> →\r\n <a href=\"/blog/entry/121170\">plusMinusPermutation computing error</a>\r\n <img alt=\"Text created or updated\" title=\"Text created or updated\" src=\"//codeforces.org/s/81027/images/icons/x-update-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/altforminuscontribution\" title=\"Newbie altforminuscontribution\" class=\"rated-user user-gray\">altforminuscontribution</a> →\r\n <a href=\"/blog/entry/121162\">My screen get unexpectedly big, what should I do</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/atcoder_official\" title=\"Unrated, atcoder_official\" class=\"rated-user user-black\">atcoder_official</a> →\r\n <a href=\"/blog/entry/121120\">We will hold UNIQUE VISION Programming Contest 2023 Autumn(AtCoder Beginner Contest 323)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/YouStill_DontKnowMeYet\" title=\"Candidate Master YouStill_DontKnowMeYet\" class=\"rated-user user-violet\">YouStill_DontKnowMeYet</a> →\r\n <a href=\"/blog/entry/117659\">[GYM] Al-Baath Collegiate Programming Contest 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/ankancool\" title=\"Expert ankancool\" class=\"rated-user user-blue\">ankancool</a> →\r\n <a href=\"/blog/entry/121136\">Invitation to AstroByte 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/GeZhiyuan\" title=\"Grandmaster GeZhiyuan\" class=\"rated-user user-red\">GeZhiyuan</a> →\r\n <a href=\"/blog/entry/120943\">Codeforces Round 901 (Div. 1, Div. 2) Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a> →\r\n <a href=\"/blog/entry/120772\">PSA: Increase your stack size before the Meta Hacker Cup, here's how</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/dino_merlin\" title=\"Expert dino_merlin\" class=\"rated-user user-blue\">dino_merlin</a> →\r\n <a href=\"/blog/entry/121145\">Intuitive approach for CEOI Kangaroo?</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/icecuber\" title=\"Grandmaster icecuber\" class=\"rated-user user-red\">icecuber</a> →\r\n <a href=\"/blog/entry/70018\">CSES DP section editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bn00b\" title=\"Newbie Bn00b\" class=\"rated-user user-gray\">Bn00b</a> →\r\n <a href=\"/blog/entry/98820\">[FEATURE REQUEST : ATCODER] TOPICS TAGS AND SORTING BY SOLVE COUNT</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a> →\r\n <a href=\"/blog/entry/121163\">AtCoder Regular Contest 166 Announcement</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/windva\" title=\"Grandmaster windva\" class=\"rated-user user-red\">windva</a> →\r\n <a href=\"/blog/entry/120644\">Codeforces Round 899 (Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Misa-Misa\" title=\"Expert Misa-Misa\" class=\"rated-user user-blue\">Misa-Misa</a> →\r\n <a href=\"/blog/entry/121157\">Someone please help me understand this.</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/shivam565\" title=\"Specialist shivam565\" class=\"rated-user user-cyan\">shivam565</a> →\r\n <a href=\"/blog/entry/108348\">Total number of subarrays with sum atmost k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n </ul>\r\n </div>\r\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/recent-actions\">Detailed →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n</div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li><a\r\n href=\"/profile/fchirica\">fchirica</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/fchirica\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/fchirica\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/fchirica\">Submissions</a></li>\r\n <li><a\r\n href=\"/groups/with/fchirica\">Groups</a></li>\r\n <li><a\r\n href=\"/contests/with/fchirica\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/fchirica\">Problemsetting</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/fchirica\" style=\"text-decoration:none;color:black !important;\">fchirica's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"10531\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/10476\"> <p>Codeforces Round #225 — Editorial</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/fchirica\" title=\"Candidate Master fchirica\" class=\"rated-user user-violet\">fchirica</a>,\r\n <span class=\"format-humantime\" title=\"Jan/20/2014 22:18\">10 years ago</span>,\r\n \r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><h1><a href=\"/contest/384/problem/A\" title=\"Codeforces Round 225 (Div. 2)\">384A - Coder</a></h1><p>Usually, when you don’t have any idea how to approach a problem, a good try is to take some small examples.</p><p>So let’s see how it looks for N = 1, 2, 3, 4 and 5. With C I noted the coder and with * I noted an empty cell.</p><p><img alt=\" \" src=\"/predownloaded/8f/89/8f899efd227362957f283123a7927c7c8a300667.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>By now you should note that answer is N ^ 2 / 2 when N is even and (N ^ 2 + 1) / 2 when N is odd. Good. Generally, after you find a possible solution by taking examples, you need to prove it, then you can code it.</p><p>In order to proof it, one needs to do following steps:</p><p>1/ prove you can always build a solution having N ^ 2 / 2 (or (N ^ 2 + 1) / 2) pieces.</p><p>2/ prove that N ^ 2 / 2 (or (N ^ 2 + 1) / 2) is maximal number – no other bigger solution can be obtained.</p><p>For proof 1/ imagine you do coloring like in a chess table.</p><p><img alt=\" \" src=\"/predownloaded/50/12/50120d92bd0cea3d6a434d09ab4754ea20342351.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>The key observation is that by placing all coders on black squares of table, no two coders will attack. Why? Because a piece placed at a black square can attack only a piece placed at a white square. Again, why? Suppose chess table is 1-based. Then, a square (i, j) is black if and only if i + j is even. A piece placed at (i, j) can attack (i + 1, j), (i – 1, j) (i, j + 1) or (i, j – 1). The sum of those cells is i + j + 1 or i + j – 1. But since i + j is even, i + j + 1 and i + j – 1 are odd, hence white cells.</p><p>Depending on parity of N, number of black cells is either N ^ 2 / 2 or (N ^ 2 + 1) / 2. For N even, one can observe that there are equal amount of black and white cells. Total number of cells is N ^ 2, so number of black cells is N ^ 2 / 2. For N odd, number of black cells is number of white cells + 1. We can imaginary add a white cell to the board. Now, number of black cells will be also equal to number of white cells, so answer is (N ^ 2 + 1) / 2.</p><p>2/ Two coders attack each other if they are placed at two adjacent cells, one black and other one white. One needs to prove that adding more than number from 1/ will cause this to happen. If you place a coder at a white cell, you won’t be able to place at least one coder at a black cell, so in best case you don’t win anything by doing this. Hence, it’s optimally to place all coders on same color cells. Since cells colored in black are always more or equal to white ones, it’s always optimally to choose black color. But number from 1/ is the number of cells having black color. Adding one more piece will force you to add it to a white color cell. Now, you’ll have a piece placed at a black colored cell and one placed at an adjacent white colored cell, so two coders will attack. Hence, we can’t place more than number from 1/ pieces.</p><p>Code: <a href=\"http://pastie.org/8651801\">http://pastie.org/8651801</a></p><h1><a href=\"/contest/384/problem/B\" title=\"Codeforces Round 225 (Div. 2)\">384B - Multitasking</a></h1><p>Let’s start by saying when array A[] is sorted:</p><p>1/ is sorted in ascending order when i < j and A[i] <= A[j]. It is NOT sorted when i < j and A[i] > A[j].</p><p>2/ is sorted in descending order when i > j and A[i] <= A[j]. It is NOT sorted when i > j and A[i] > A[j].</p><p>Iahub can choose 2 indices i, j and swap values when A[i] > A[j]. If A[i] <= A[j], he’ll ignore operation. Hence, if he wants to sort all arrays in ascending order, he chooses indices i, j when i < j and perform operation. Otherwise, in all his operations he uses indices i, j such as i > j. A “good” operation is when choosing indices i < j for ascending order sorting and i > j for descending order sorting. By doing only good operations, after an array is sorted, it will stay sorted forever (for a sorted array, all good operations will be ignored).</p><p>From here we get our first idea: use any sorting algorithm you know and sort each array individually. When print swaps done by sorting algorithm chosen, print them as good operations. However, sorting each array individually can cause exceeding M * (M — 1) / 2 operations limit. Another possible solution would be, after you did an operation to an array, to update the operation to all arrays (you printed it, so it counts to M * (M — 1) / 2 operations limit; making it to all arrays will help sometimes and in worst case it won’t change anything). However, you need to code it very careful in order to make this algorithm pass the time limit. Doing this in a contest is not the best idea, especially when implementation could be complicated and you have no guarantee it will pass time limit.</p><p>So what else can we do? We can think out of box. Instead of sorting specific N arrays, you can sort all possible arrays of length M. Find a sequence of good operations such as, anyhow I’d choose an array of size M, it will get sorted ascending / descending.</p><p>I’ll show firstly how to do for ascending sorting. At position 1 it needs to be minimal element. Can we bring minimal element there using good operations? Yes. Just do “1 2” “1 3” “1 4” ... “1 M”. It basically compares element from position 1 to any other element from array. When other element has smaller value, swap is done. After comparing with all M elements, minimal value will be at position 1. By now on I’ll ignore position 1 and move to position 2. Suppose array starts from position 2. It also needs minimal value from array, except value from position 1 (which is no longer in array). Hence doing “2 3” “2 4” “2 5” ... “2 M” is enough, by similar reasons. For a position i, I need minimal value from array, except positions 1, 2, ..., i – 1. I simply do “i i+1” “i i+2” ... “i M-1” “i M”. By arriving at position i, array will be sorted ascending. The algorithm is simply:</p><p>for (int i = 1; i < M; ++i)</p><p>for (int j = i + 1; j <= M; ++j)</p><p>cout << i << “ “ << j << “\\n”;</p><p>This algorithm does exactly M * (M — 1) / 2 moves.</p><p>Can you find out how to sort array in descending order? Try to think yourself, then if you don’t get it read next. At first position of a descending array it needs to be maximal value. Similarly to ascending order, we can do “2 1” “3 1” “4 1” ... “M 1”. When I’m at a position i and I compare its value to value from position 1, doing operation “i 1” checks if A[i] > A[1]. If so, it swaps A[i] and A[1], so position 1 will contain now the maximum value so far. Similarly to logic from ascending order, when I’m at position i, I need maximum value from array except positions 1, 2, ..., i – 1, so I do “i+1 i” “i+2 i” ... “M i”. Algorithm is:</p><p>for (int i = 1; i < M; ++i)</p><p>for (int j = i + 1; j <= M; ++j)</p><p>cout << j << “ “ << i << “\\n”;</p><p>Obviously, this does as well M * (M — 1) / 2 operations worst case. All algorithm is about 10 lines of code, much better than other solution, which requires two manually sorts and also has a chance to exceed TL.</p><p>Code: <a href=\"http://pastie.org/8651809\">http://pastie.org/8651809</a></p><h1><a href=\"/contest/384/problem/C\" title=\"Codeforces Round 225 (Div. 2)\">384C - Milking cows</a></h1><p>A good strategy to approach this problem is to think how optimal ordering should look like. For this, let’s calculate for each 2 different cows i and j if cow i needs to be milked before or after cow j. As we’ll show, having this information will be enough to build optimal ordering. It is enough to consider only cases when i < j, case when i > j is exactly the opposite of case i < j. For formality, I’ll call the optimal ordering permutation and lost milk the cost of permutation.</p><p>So, for an optimal permutation P let’s take 2 numbers i < j and see in which cases i should appear before j in permutation (i is before j if P[pos1] = i, P[pos2] = j and pos1 < pos2; otherwise we’ll call i is after j). We have 4 possible cases:</p><p>1/ A[i] = 0 and A[j] = 0</p><p>If we put i before j, no additional cost will be added. Since j is in right of i and i only adds cost when it finds elements in left of i, j won’t be affected when processing i. When processing j, i will be already deleted so it won’t affect the cost either. Hence, we can put i before j and no cost will be added.</p><p>2/ A[i] = 0 and A[j] = 1</p><p>Here, i and j can appear in arbitrary order in permutation (i can be before or after j). No matter how we choose them, they won’t affect each other and cost will remain the same.</p><p>3/ A[i] = 1 and A[j] = 0</p><p>As well, here i and j can appear in arbitrary order. If we choose i first, j will be in right of it, so cost of permutation will increase by one. If we choose j first, i will be in left of it so cost of permutation will increase as well. No matter what we do, in this case cost of permutation increases by 1.</p><p>4/ A[i] = 1 and A[j] = 1</p><p>Here, i needs to be after j. This adds 0 cost. Taking i before j will add 1 cost to permutation (since j is in right of i).</p><p>Those 4 cases show us how a minimal cost permutation should look. In a permutation like this, only case 3/ contributes to final cost, so we need to count number of indices i, j such as i < j and A[i] = 1 and A[j] = 0 (*). If we show a permutation following all rules exists, task reduces to (*).</p><p>By cases 2/ and 3/ it follows that in an optimal permutation, it only matters order of elements having same value in A[]. We can put firstly all elements having value 0 in A[], then all elements having value 1 in A[]. We can order elements having value 0 by case 1/ and elements having value 1 by case 4/. More exactly, suppose i1 < i2 < ... < im and (A[i1] = A[i2] = ... = A[im] = 0) and j1 > j2 > ... > jn (A[j1] = A[j2] = ... = A[jn] = 1). Then, a permutation following all rules is {i1, i2, ..., im, j1, j2, ..., jn}. This permutation can always be built.</p><p>Hence, task reduces to (*): count number of indices i, j such as i < j and A[i] = 1 and A[j] = 0. We can achieve easily an O(N) algorithm to do this. Let’s build an array cnt[j] = number of 0s in range {j, j + 1, ..., N} from array A. We can easily implement it by going backwards from N to 1. The result is sum of cnt[i], when A[i] = 1.</p><p>Code: <a href=\"http://pastie.org/8651813\">http://pastie.org/8651813</a></p><h1><a href=\"/contest/384/problem/D\" title=\"Codeforces Round 225 (Div. 2)\">384D - Volcanoes</a></h1><p>Our first observation is that if there is a path from (1, 1) to (N, N), then the length of path is 2 * N – 2. Since all paths have length 2 * N – 2, it follows that if there is at least one path, the answer is 2 * N – 2 and if there isn’t, the answer is -1. How to prove it? Every path from (1, 1) to (N, N) has exactly N – 1 down directions and exactly N – 1 right directions. So, total length for each path is N – 1 + N – 1 = 2 * N – 2. </p><p>So we reduced our problem to determine if there is at least one path from (1, 1) to (N, N). This is the challenging part of this task, considering that N <= 10 ^ 9. How would you do it for a decently small N, let’s say N <= 10^3 . One possible approach would be, for each row, keep a set of reachable columns. We could easily solve this one by doing this: if (i, j) denotes element from ith row and jth column, then (i, j) is (is not) reachable if:</p><p>if (i, j) contains a volcano, then (i, j) is not reachable. Otherwise, if at least one of (i – 1, j) and (i, j – 1) is reachable, then (i, j) is reachable. Otherwise, (i, j) is not reachable.</p><p>What’s the main problem of this approach? It needs to keep track of 10^9 lines and in worst case, each of those lines can have 10^9 reachable elements. So, worst case we need 10^9 * 10^9 = 10^18 operations and memory.</p><p>Can we optimize it? We can note for beginning that we don’t need to keep track of 10^9 lines, only m lines are really necessarily. We need only lines containing at least one obstacle (in worst case when each line contains only one obstacle, we need m lines). How to solve it this way? Suppose line number x contains some obstacles and lines x + 1, x + 2, x + 3 do not contain any obstacle. Suppose we calculated set S = {y | cell (x, y) is reachable}. How would look S1, S2, S3 corresponding to lines x + 1, x + 2, x + 3? For S1, we can reach cell (x + 1, ymin), where ymin is minimal value from set S. Then, we can also reach {ymin + 1, ymin + 2, ..., N}, by moving right from (x + 1, ymin). So S1 = {ymin, ymin + 1, ..., N}. How do S2 and S3 look? It’s easy to see that they’ll be as well {ymin, ymin + 1, ..., N}. So we get following optimization: suppose set of lines containing at least one obstacle is {L1, L2, ..., Lk}. We need to run algorithm only for lines L1, L1 + 1, L2, L2 + 1, L3, L3 + 1, ..., Lk, Lk + 1.</p><p>It looks like we didn’t make anything with this optimization. Even if we calculate for m lines, each line can still have 10^9 reachable positions. So worst case we perform 10^14 operations. We need something better for managing information from a line. You can note that for a given line y, there are a lot of positions having consecutive values. There are a lot of positions (x, y) and (x, y + 1) both reachable. This should give us following idea: what if instead of keeping reachable positions, we keep reachable ranges? That is, for each line x we keep a set of ranges S = {(a, b) | all cells (x, k) with a <= k <= b are reachable}. </p><p>How many ranges can it be for a line? If the line contains m obstacles, there are m + 1 ranges. Suppose for line x all cells are reachable, but for line x + 1 cells (x + 1, 3) (x + 1, 5) (x + 1, N – 1) are blocked. Then, the ranges of reachable cells are [1, 2] [4, 4], [6, N – 2] and [N, N]. By now, we get worst case m lines and worst case each line having m elements, so in worst case we’d have to handle m * m = 10 ^ 10 events. This may still look too much, but happily this bound is over estimated. If a line has o obstacles, there can be at most o + 1 ranges. If lines L1, L2, ..., Lk have {o1, o2, ..., ok} obstacles, there’ll be at most o1 + o2 + ... + ok + k ranges. But o1 + o2 + ... + ok = m and also k is at most m (proved above why we’re interested in at most m lines), so in worst case we get m + m = 2 * m ranges. Yaay, finally a decent number of states for this problem :)</p><p>So, we iterate each line we’re interested in. Let’s find set of ranges for this line, thinking that all cells from line above are reachable. This is easy to do. After we get our ranges like all cells from above can be visited, let’s think how having obstacles above can influence current ranges. After adding ranges from above, current ranges can’t increase (obviously), they can only decrease, remain the same or some of them can become empty. So, let’s take each range [a, b] from current line and see how it will transform after adding ranges from previous line. </p><p>Given range [a, b], it can transform only in [a’ , b] with a’ >= a. If a’ > b, then obviously range is empty. Why second number of range keeps constant? Let a’ smallest reachable column from current line which is in range [a, b]. It’s enough to check a’ >= a, as if a’ > b, range will be empty. It’s obviously why we need to keep a’ smallest value possible >= a: we’re interested to keep range as big as possible and as less as we cut from left, as big it is. Once we’ve found a’ in range [a, b] (or a’ > b if range is empty) all cells {a’ + 1, a’ + 2, ..., b} are reachable as well by going right from a’, so if interval is not empty, then second number defining it remains b.</p><p>Next question is how to find a’ fast enough. In order a point a’ to be reachable on current range, it also needs to exist a range on previous line containing it. If the range from previous line is [pa, pb] then a’ needs to follow 3 conditions:</p><p>a’ minimal such as</p><p>pa <= a’ <= pb</p><p>a’ >= a</p><p>What if instead of finding a’ we find [pa, pb]? Then a’ is max(pa, a). In order a’ to be as small as possible, since a is constant, pa needs to be as small as possible. So we reduced it to:</p><p>pa minimal pb >= a’ >= a <=> pb >= a</p><p>Intervals from previous line are disjoint, no 2 intervals cross each other. It means that if pb is minimal, than pa is minimal too (if we increase pb, then pa will increase too, so it won’t be minimal). Hence, you need to find an interval [pa, pb] such as pb is minimal and pb >= a. Then, a’ is max(a, pa). This is easy to do if we sort all intervals from previous line increasing by second value (pb), then we binary search for value a. </p><p>Finally, after running algorithm for all lines, last range from last line has second number N (assuming ranges are sorted increasing by second value), then there exist a path, otherwise there does not exist. This algorithm should run O(m * logm) worst case, good enough to pass. </p><p>Code: <a href=\"http://pastie.org/8651817\">http://pastie.org/8651817</a></p><h1><a href=\"/contest/384/problem/E\" title=\"Codeforces Round 225 (Div. 2)\">384E - Propagating tree</a></h1><p>This is kind of task that needs to be break into smaller subproblems that you can solve independently, then put them together and get solution.</p><p>Let’s define level of a node the number of edges in the path from root to the node. Root (node 1) is at level 0, sons of root are at level 1, sons of sons of root are at level 2 and so on.</p><p>Now suppose you want to do an operation of type 1 to a node x. What nodes from subtree of x will be added +val (a positive value)? Obviously, x will be first, being located at level L. Sons of x, located at level L + 1 will be added –val. Sons of sons, located at level L + 2, will be added value +val again. So, nodes from subtree of x located at levels L, L + 2, L + 4, ... will be added a +val, and nodes located at levels L + 1, L + 3, L + 5 will be added a –val. Let’s take those values of L modulo 2. All nodes having remainder L modulo 2 will be added a +val, and nodes having reminder (L + 1) modulo 2 will be added –val. In other words, for a fixed x, at a level L, let y a node from subtree of x, at level L2. If L and L2 have same parity, +val will be added to y. Otherwise, -val will be added to y.</p><p>From here we have the idea to split nodes of tree in 2 sets – those being located at even level and those being located at odd level. What still makes the problem hard to solve? The fact that we have a tree. If nodes from a subtree would be a contiguous sequence instead of some nodes from a tree, problem would be simpler: the problem would reduce to add / subtract values to all elements of a subarray and query about a current value of an element of array. So, how can we transform tree to an array, such as for a node x, all nodes from subtree of x to be a subarray of array?</p><p>The answer is yes. We can do this by properties of DFS search. Before reading on, make sure that you know what is discovery time and finish time in a DFS search. Let’s build 3 arrays now – discover[], representing nodes in order of their discover times (a node is as before in discover as it has a small discover time), begin[] = for a node, in which time it was discovered and end[] = what’s last time of a discovered node before this node finishes. For a subtree of x, all nodes in the subtree are nodes in discover from position begin[x] to end[x].</p><p>Example: suppose you have tree 1-5; 1-6; 6-7; 6-4; 4-2; 4-3</p><p>Discover is {1, 5, 6, 7, 4, 2, 3}.</p><p>begin is {1, 6, 7, 5, 2, 3, 4}.</p><p>end is {7, 6, 7, 7, 2, 7, 4}.</p><p>What’s subtree of node 6? elements of discover from position begin[6] to end[6]. In this case, from 3 to 7, so elements {6, 7, 4, 2, 3}. You can see it’s correct and take more examples if you want :)</p><p>Now, we reduced problem to: you’re given an array A. you can perform 2 operations:</p><p>1/ increase all elements from a range [x, y] to a value val (val can be negative, to treat subtractions)</p><p>2/ what’s current value of an element from position pos.</p><p>Those who solved “Iahub and Xors” from my last round, CF 198, should probably say they saw something similar before. If you didn’t solve problem before, I encourage you to do it after you solve this one, it uses a similar idea to what will follow now. Also, if you don’t know Fenwick trees, please read them before moving on. An alternative would be for this task using segment trees with lazy update, but I see this one more complicated than needed.</p><p>I’ll use now a not so common approach when dealing with data structures. Instead of keeping in a node the result, like you usually do, I’ll keep just an auxiliary information. So what algorithm proposed does:</p><p>Let A an array, initially with all elements 0.</p><p>When you need to update range [x, y] with value val, you simply do A[x] += val and A[y + 1] -= val.</p><p>When you need to answer a query about position pos, you output A[1] + A[2] + ... + A[pos].</p><p>Implemented brute force, you get O(1) per update and O(N) per query. However, these both are operations supported by a Fenwick tree, so you can get O(logN) per operation.</p><p>It may not be very clear why this algorithm works. Let’s take a closer look: an update needs to add value val only to range [x, y]. When you query a position pos, let’s see if algorithm handles it correctly:</p><p>1/ pos < x. In this case, result must not be affected by my update. Since pos < x and I only updated 2 values with indices >= x, when doing A[1] + A[2] + ... + A[pos] it won’t matter at all I did that update – at least not for this query.</p><p>2/ x <= pos <= y. Here, for a pos, I need to add value val only once. We add it only at A[x] – in this way it will be counted once, and it will be considered for each elements from range [x, y] (since an element at position p from range [x, y] has p >= x, in A[1] + A[2] + ... + A[p] I’ll have to consider A[x]).</p><p>3/ pos > y. Here I don’t have to consider the query. But it would be considered when processing A[x]. But if I add to A[y + 1] value –val I’ll just cancel the value previously added.</p><p>Code (actually we use just one Fenwick tree instead of 2, can you think why it works? :) ) : <a href=\"http://pastie.org/8651824\">http://pastie.org/8651824</a></p><h1><a href=\"/contest/383/problem/D\" title=\"Codeforces Round 225 (Div. 1)\">383D - Antimatter</a></h1><h2>Author's solution</h2><p>The problem is: given an array, iterate all possible subarrays (all possible elements such as their indexes are consecutive). Now, for a fixed subarray we need to know in how many ways we can color its elements in black and white, such as sum of black elements is equal to sum of white elements. The result is sum of this number, for each subarray.</p><p>Let’s solve an easier problem first. This won’t immediately solve the harder version, but it will be useful later. Suppose you’ve fixed a subarray. In how many ways can you color it with black and white? Suppose subarray has N elements and sum of them is M. Also, suppose for a coloring, sum of blacks is sB and sum of whites is sW. For coloring to be valid, sB = sW. But we also know that sB + sW = M (because each element is colored by exactly one color). We get that 2 * sB = M, so sB = M / 2. The problem is now: in how many ways can we color elements in black such as sum of blacks is M / 2 (after we fix a black coloring, we color with white non colored elements; sum of white colored elements is also M / 2). This is a well known problem: Knapsack problem. Let ways[i][j] = in how many ways one can obtain sum j from first i elements. When adding (i + 1) object, after ways[i] is calculated, for a fixed sum j we can do 2 things: add (i + 1) object to sum j or skip it. Depending of what we chosen, we add value ways[i][j] to ways[i + 1][j + value[i + 1]] or to ways[i + 1][j]. The result is in ways[N][M / 2]. This works in O(N * M) time.</p><p>An immediate solution can be obtained now: take all subarrays and apply above approach. This leads to an O(N ^ 2 * M ^ 2) solution, which is too much. One can reduce complexity to O(N ^ 2* M) by noting that processing subarray [i, j] can be done with already calculated values for subarray [i, j – 1]. Hence, instead of adding N elements, it’s enough to add 1 element to already calculated values (element from position j). Sadly, O(N ^ 2 * M) is still too slow, so we need to find something better. The solution presented below will look forced if you didn’t solve some problems with this technique before. It’s hard to come with an approach without practicing this kind of tasks. But don’t worry, as much as you practice them, as easily you’ll solve those problems.</p><p>We’ll solve task by divide and conquer. Complexity of this solution is O(N * M * logN). Let f(left, right) a function that counts number of colorings for each subarray [i, j], such as subarray [i, j] is included in subarray [left, right] (left <= i <= j <= right). Answer is in f(1, N). The trick is to define a value med = (left + right) / 2 (very frequent trick in divide and conquer problems, called usually a median). We can next classify [i, j] subarrays in 3 types:</p><p>1/ i <= med j <= med</p><p>2/ i > med j > med</p><p>3/ i <= med j > med</p><p>We can solve 1/ and 2/ by calling f(left, med) and f(med + 1, right). The remained problem is when i <= med and j > med. If we solve 3/ in O((right – left) * M) time, this will be enough to overall achieve O(N * M * logN) (for this moment trust me, you’ll see later why it’s so :) ).</p><p>Let’s denote by i1 last i1 elements from subarray [left, med]. Also, let’s note by i2 first i2 elements from subarray [med + 1, right]. For example, let left = 1 and right = 5, with array {1, 2, 3, 4, 5}. med is 3 and for i1 = 2 and i2 = 1, “left” subarray is {2, 3} and “right” subarray is {4}. By iterating i1 from 1 to med – left + 1 and i2 from 1 to right – med and then unite subarrays i1 and i2, we obtain all subarrays described in 3/ . Let’s denote by j1 sum of a possible black coloring of i1. Similarly, j2 is sum of a possible black coloring of i2.</p><p>Suppose we fixed i1, i2, j1 and j2. When it’s the coloring valid? Let S sum of united subarrays i1 and i2 (S = value[med – i1 + 1] + value[med – i1 + 2] + ... + value[med] + value[med + 1] + ... + value[med + i2 – 1] + value[med + i2]). Now it’s time to use what I explained at the beginning of solution. The coloring is good only when j1 + j2 = S / 2. We can rewrite the relation as 2 * (j1 + j2) = sum_of_elements_from_i1 + sum_of_elements_from_i2. We can rewrite it even more:</p><p>2 * j1 + 2 * j2 — sum_of_elements_from_i1 — sum_of_elements_from_i2 = 0</p><p>2 * j1 – sum_of_elements_from_i1 = sum_of_elements_from_i2 – 2 * j2 = combination_value</p><p>This relation is the key of solving problem. You can see now that relation is independent in “left” and “right” side. We calculate left[i1][j1] and right[i2][j2] = in how many ways can I obtain sum of blacks j1 (j2) from first i1 (i2) from left (right) side. Let’s calculate also count[value] = in how many ways can I obtain combination_value equal to value in the right side. For some fixed (i2, j2) I add to count[sum_of_elements_from_i2 – 2 * j2] value right[i2][j2]. In this way count[] is calculated correctly and completely. Now, let’s fix a sum (i1, j1) in the left side. We’re interested how many good colorings are such as there exist a coloring of j1 in i1 elements (the endpoint of “left” is fixed to be i1 and I need to calculate endpoints i2 for right, then to make colorings of i2). A coloring is good if combination_value of (i1, j1) and (i2, j2) is equal. Hence, I need to know in how many ways I can color i1 elements to obtain sum j1 and also I need to know in how many ways I can color elements from right to obtain same combination_value as it’s in the left. It’s not hard to see that answer for a fixed (i1, j1) is left[i1][j1] * count[2 * j1 – sum_of_elements_from_i1]. This takes O((right – left) * M) time.</p><p>The only thing remained in the problem is to see why complexity is O(N * M * logN). We can assume N is a power of 2 (it not, let’s round N to smallest power of 2 bigger than N; complexity for N is at least as good as complexity for this number). Draw a binary complete tree with N nodes. Each node corresponds to an appeal of f(). For a level, exactly O(N * M) operations are performed. To see why:</p><p>For level 1, there’ll be 1 node performing N * M operations.</p><p>For level 2, there’ll be 2 nodes performing (N / 2) * M operations. Summing up we get O(N * M).</p><p>For level 3, there’ll be 4 nodes performing (N / 4) * M operations. Summing up we get O(N *M) as well.</p><p>and so on.</p><p>So for each level we perform O(N * M) operations. A binary complete tree has maximum O(logN) levels, so overall complexity is O(N * M * logN).</p><p>Code: <a href=\"http://pastie.org/8651826\">http://pastie.org/8651826</a></p><h2>Solution fount by contestants</h2><p>This was totally unexpected to us :) Good job finding it, you guys are really smart. </p><p>We observe that x units of antimatter is the same thing as -x units of matter. Then we can consider that an element produces either x or -x units of matter. A valid substring is one that can have the sum of the elements 0. The problem is reduced to finding how many different substrings can we have with sum 0 (a substring is different than another one if it has different indices, or if at least one element produces matter in one and antimatter in the other).</p><p>This problem can be solved with dynamic programming. We will hold D[i][j] = the number of substrings that end in element i, and have sum j. It's easy to see that D[i + 1][j] = D[i][j — x] + D[i][j + x], where x is the value of the current element (we can put either -x or x). After we finish computing all the values for current i, we add to the solution D[i][0] (how many valid substrings do we have). After that, we add 1 to D[i][0], meaning that there is an empty substring starting at position i (however, we don't need to add it to the answer).</p><p>For a code, check passing submissions during contest. </p><h2><a href=\"/contest/383/problem/E\" title=\"Codeforces Round 225 (Div. 1)\">383E - Vowels</a></h2><h2>Author's solution</h2><p>Let's iterate over all possible vowel sets. For a given set {x1, x2, ..., xk} we're interested in number of correct words from dictionary. After a precalculation, we can do it in O(k).</p><p>Suppose our current vowel set is {x1, x2, ..., xk}. How many words are covered by the current vowels? By definition, we say a word is covered by a set of vowels if at least one of 3 letters of word is in vowel set. We can calculate this number using principle of inclusion and exclusion. We’ll denote by |v1, v2, v3, ...| = number of words containing ALL of vowels v1, v2, v3, ... . Using principle of inclusion and exclusion we get:</p><p>number_of_words_covered = |x1| + |x2| + .. + |xk| — |x1, x2| — |x1, x3| — .... + |x1, x2, x3| + |x1, x2, x4| + .... + |xk-2, xk-1, xk|. This formula is simply a reformulation of principle of inclusion and exclusion. You can easily observe that |v1, v2, ..., vk| makes sense only when k is at most 3, as no word from input can contain 4 or more letters (and hence can’t contain 4 or more vowels). </p><p>Example:</p><p>Suppose words are abc, abd and bcd. </p><p>|a| = 2 (first 2 words both contain character a).</p><p>|a, b| = 2 (as well, first 2 words contain characters a and b).</p><p>|b| = 3 (all 3 words contain character b).</p><p>|a, b, d| = 1 (only second word contains all 3 characters).</p><p>Also, note how principle of inclusion and exclusion works. number of words covered for vowels {a, b} is |a| + |b| — |a, b| = 2 + 3 – 2. Indeed, answer is 3.</p><p>We divide our problem in 3 subproblems. First one, for a vowel set, compute sum of |a|, where a is a letter from subset. Second, compute sum of |a, b|, where both a and b are letters from set. Third, compute sum of |a, b, c|, where a, b, c are letters from set. As stated, the answer is number_from_1st_step + number_from_3rd_step – number_from_2nd_step. If you followed me, you’ll see that we want to compute results for each subproblem in O(queryLetters).</p><p>First subproblem can be solved trivially in O(queryLetters). Let array single[], with following meaning: single[c] is how many words contain character c. It can be trivially precomputed in O(24 * N). Note that if a word contains twice/third times a character c, it needs to be counted only one (e.g. word aba will add only 1 to single[a]). For compute result of this subproblem for a given set of vowels, I’ll take all letters from set. If letter belongs to set, I add to result single[letter]. This step can be also be solved in O(1), but there’s no need, since other subproblems allow only an O(queryLetters) solution. </p><p>For second and third subproblems it’s a little more difficult. I’ll present here how to solve second subproblem and some hints for third one (if you understand second, with hints you should be able to solve third one by your own).</p><p>Similarly to first step, I’ll define a matrix double[c1][c2] = how many words contain both characters c1 and c2. A trivially solution would be, for a given vowel set, take all combinations of letters c1 and c2 that belong to set and add to result value double[c1][c2]. However, this solves each query in O(queryLetters^2), which is too slow.</p><p>Note, if we’d have 12 letters, instead of 24, this approach would be fast enough. From here it comes a pretty classical idea in exponential optimization: meet in the middle attack. We split those 24 letters in 2 groups: first 12 letters and last 12 letters. The answer for a subset is sum of double[c1][c2] (when c1 and c2 belong to current vowel set) when</p><p>1/ c1 and c2 belong to first 12 letters</p><p>2/ c1 and c2 belong to last 12 letters</p><p>3/ c1 belongs to first 12 letters and c2 belongs to last 12 letters</p><p>1/ and 2/ can be immediately precalculated as stated above, in O(2 ^ 12 * 12 ^ 2). We’ll remember results for each half using bitmasks arrays. Let Half1[mask] = sum over double[c1][c2], when c1 and c2 are in first 12 letters and correspond to 1 bits of mask. Half2[mask] is defined similarly, but for last 12 letters (e.g. subset {a, c, d} corresponds to bitmask 2^0 + 2^2 + 2^3 = 13 in first half and subset {m, n, p} corresponds to bitmask 2^0 + 2^1 + 2^3 = 11 for second half). Now, for a given subset, one can answer first 2 parts in O(queryCount) worst case (read input for a query and convert it to bitmasks). </p><p>How to answer 3? With another precalculation, of course. We know c1 letter needs to be in first 12 letters and c2 needs to be in last 12 letters. The precalculation we do here is: mixed_half[mask][i] = sum over |c1, c2|, when c1 belongs to first half and is a 1 bit of mask and c2 is i-th character of second half. Hence, for a query, we can fix character from second half (c2, by iteration of query letters from second half) and know sums of |c1, c2| between it and all available characters from first half after we do this precalculation. Also, precalculation is done trivially in O(2 ^ 12 * 12^2): fix mask, fix i and then iterate over 1 bits from mask and add double[c1][c2]. </p><p>Third subproblem is left, but it can be done similarly to second one. Instead of double[c1][c2], we’ll have triple[c1][c2][c3] = how many words contain all 3 characters c1, c2 and c3? We also do meet in the middle here, divide those 24 letters into 2 sets of 12 letters. We have 4 cases:</p><p>1/ c1, c2, c3 belong to first half</p><p>2/ c1, c2, c3 belong to second half</p><p>3/ c1, c2 belong to first half and c3 to second half</p><p>4/ c1 belongs to first half and c2, c3 to second half</p><p>1/ and 2/ are done brute force, like in second subproblem (the only difference is we choose 3 characters instead of 2, having complexity O(2 ^ 12 * 12 ^ 3)). For 3/ and 4/ we also precompute 2 matrixes: </p><p>mixed_two_one[mask][i] = c1 and c2 belong to mask from first half and c3 is i-th character from second half </p><p>and </p><p>mixed_one_two[mask][i] = c1 is i-th character from first half and c2, c3 belong to mask from second half. </p><p>Those can also be calculated in O(2 ^ 12 * 12^3).</p><p>So precalculation part is O(2 ^ 12 * 12 ^ 3) = 7077888 operations.</p><p>For calculate answering queries complexity, take all numbers from 0 to 2^24 — 1 and sum their bit count. This is a well known problem, the sum is 0 * C(24, 0) + 1 * C(24, 1) + ... + 24 * C(24, 24) = 201326592. In total we get 208404480 operations. C++ source makes them in 2 seconds. </p><p>Code: <a href=\"http://pastie.org/8651829\">http://pastie.org/8651829</a></p><h2>Solution fount by contestants</h2><p>Like in D1 D task, official solution was over complicated. This solution is more simple to understand, code and it's more elegant. If someone wants to complicate his life, (s)he can code also official solution :)</p><p>Let's start by assigning a bitmask to each word in following way: ith bit is 1 if and only if letter ('a' + i) appears in the current word. For example, for word acd, its bitmask is 2^0 + 2^2 + 2 ^ 3 = 13 and for word aab its bitmask is 2^0 + 2^1 = 3. After reading the words from dictionary, we store a matrix cnt[mask] = how many words from dictionary correspond to mask?</p><p>We iterate bitmasks from 0 to 2^24 — 1, this time corresponding to each possible question of Iahubina. Let's focus on a bitmask X. We need to get sum of cnt[mask], when mask and X share at least one common bit having value 1 (formally (X AND mask) > 0). In order to do this, we need a reduction which may be not so obvious. </p><p>What if instead of counting all words containing at least one of vowels {w1, w2, ..., wk} we count all words which don't contain ANY of vowels {w1, w2, ..., wk}? Suppose this number is ret. Then, all words containing at least one of vowels is N — ret. From all words, we erase those words which do not contain any vowels from set {w1, w2, ..., wk} (and which obviously are wrong words). Obviously, it's left only words containing at least one vowel, so good words. Now, for a word not to contain any of vowels {w1, w2, ..., wk} it needs to contains ONLY vowels from set {"a", "b", "c", ..., "x"} \\ {w1, w2, ..., wk} (set of allowed letters from which we erased vowels w1, w2, ..., wk}. </p><p>And this is reduction we needed. For a bitmask X we need to calculate sum of cnt[mask], where mask is a subset of X (we can set some bits from X from 1 to 0 in order to obtain mask). For a mask, let's keep this sum in res[mask]. We can calculate res array using divide and conquer.</p><p>Let's make a function solve(left, right), which completes array res in the way described above, if we consider only elements cnt[k] with left <= k < right (for simplicity, I'll consider elements which do not lie in this range to be equal to 0). Now we need to solve for a range [left, right]. Let's have in res1[] = solve(left, med) and in res2[] = solve(med, right), where med = (left + right) / 2. We need to put together res1[] and res2[] in order to obtain res[].</p><p>for (int i = left; i < med; ++i) res[i] = res1[i];</p><p>Numbers in [left, med] have most significant bit equal to 0. We can only keep it 0 and add what we calculated before. We can't add any element from res2[], because those elements have most significant bit equal to 1 and we're not allowed to change bit 0 into bit 1.</p><p>for (int i = med; i < right; ++i) res[i] = res1[i — med] + res2[i];</p><p>Here, most significant bit is 1. Adding res1[] corresponds to changing bit from 1 to 0, adding res2[] corresponds to leaving bit 1.</p><p>Of course, we need to threat the base case here, too. When left + 1 = right, res[left] = cnt[left]. We can keep only one array res[] instead of 3, I explained it this way only for simplicity. Also, there is no need for keeping separate arrays for res[] and cnt[], one can solve all task with only one array. In order to get res[], we simply call solve(0, 2^24).</p><p>Complexity of solution is O(2 ^ 24 * 24). I leave the proof homework, it's almost identical to complexity proof of D1 D "Author solution" (that with building a binary tree).</p><p>For a reference solution, check <a class=\"rated-user user-red\" href=\"/profile/Endagorion\" title=\"Grandmaster Endagorion\">Endagorion</a>'s AC source during contest. </p></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/384\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 225 (Div. 2)</a> </span>\r\n </div>\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/383\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 225 (Div. 1)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-12457-10531\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"12457\",\n blogEntryId: \"10476\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n <div style=\"font-size: 1.1rem;line-height: 11px;\">\r\n <img style=\"vertical-align: middle;\" src=\"//codeforces.org/s/81027/images/blog/tags.png\" title=\"Tags\" alt=\"Tags\"/>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=codeforces\" class=\"tag notice\" style=\"text-decoration: none;\">codeforces</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=225\" class=\"tag notice\" style=\"text-decoration: none;\">225</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=editorial\" class=\"tag notice\" style=\"text-decoration: none;\">editorial</a>\r\n </span>\r\n </div>\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-10531\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+418</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-10531\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/fchirica\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/fchirica\">\n fchirica\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Jan/20/2014 22:18\">10 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/10476#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/10476#comments\">\n 52\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"10547\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (45)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158582\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PAP\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/78534/avatar/d5bcc04085999f83.jpg'/> </a>\n <div><a href=\"/profile/PAP\" title=\"Candidate Master PAP\" class=\"rated-user user-violet\">PAP</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 22:40\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158582\" href=\"?#comment-158582\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158582\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"32\"\r\n data-commentUserId=\"78534\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+32</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158582\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>perfect editorial! thanks a lot!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158582 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158582 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158582\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158591\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/eduardische\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2320/avatar/3ac70493aa90ad2e.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/eduardische\" title=\"International Master eduardische\" class=\"rated-user user-orange\">eduardische</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 22:48\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158591\" href=\"?#comment-158591\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"158591\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"158591\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"10\"\r\n data-commentUserId=\"2320\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+10</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158591\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Just would like to report a typo in 383D contestants' solution: the formula computes D[i+1][j] and not D[i][j]. Thanks for the quick editorial!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158591 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158591 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158591\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158596\" commentParentId=\"158591\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/fchirica\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/57267/avatar/4e655c69b8ad66c2.jpg'/> </a>\n <div><a href=\"/profile/fchirica\" title=\"Candidate Master fchirica\" class=\"rated-user user-violet\">fchirica</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 22:52\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158596\" href=\"?#comment-158596\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-158591\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158596\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"15\"\r\n data-commentUserId=\"57267\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+15</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158596\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks. Fixed. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158596 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158596 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158596\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158598\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Mikester\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/109566/avatar/401b6d72d8f2e768.jpg'/> </a>\n <div><a href=\"/profile/Mikester\" title=\"Master Mikester\" class=\"rated-user user-orange\">Mikester</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 22:54\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158598\" href=\"?#comment-158598\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158598\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"13\"\r\n data-commentUserId=\"109566\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+13</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158598\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>elfus has some of the best rounds on Codeforces, and definitely the best editorials. Congratulations to you and Rares for the round !</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158598 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158598 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158598\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158599\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/iPs\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/144469/avatar/10358ae72910ceac.jpg'/> </a>\n <div><a href=\"/profile/iPs\" title=\"Expert iPs\" class=\"rated-user user-blue\">iPs</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 22:54\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158599\" href=\"?#comment-158599\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158599\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"33\"\r\n data-commentUserId=\"144469\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+33</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158599\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>best editorial I have ever seen in codeforces</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158599 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158599 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158599\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158600\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/bli0042\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/88584/avatar/51c3a9b55a3537fa.jpg'/> </a>\n <div><a href=\"/profile/bli0042\" title=\"Candidate Master bli0042\" class=\"rated-user user-violet\">bli0042</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 22:54\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158600\" href=\"?#comment-158600\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"158600\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"158600\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"88584\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158600\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For Div 2C, if A[i] = A[j] = 0 and we put i before j, won't j lose milk? Or am I misinterpreting the solution?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158600 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158600 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158600\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158601\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/aabs08\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/aabs08\" title=\"Expert aabs08\" class=\"rated-user user-blue\">aabs08</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 22:55\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158601\" href=\"?#comment-158601\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"158601\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"158601\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"9\"\r\n data-commentUserId=\"86699\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+9</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158601\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>One of the best editorials i came across in codeforces :D otherwise the editorial here are really very short and objective.</p><p>Every one here should write editorials like you :) !!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158601 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158601 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158601\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158607\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Xellos\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/69675/avatar/8526bcfc8e687b43.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/Xellos\" title=\"International Grandmaster Xellos\" class=\"rated-user user-red\">Xellos</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 23:03\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158607\" href=\"?#comment-158607\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"158607\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"158607\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"17\"\r\n data-commentUserId=\"69675\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+17</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158607\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Finally a tutorial worth upvoting!</p><p>I didn't really need to think about D. As soon as I saw the constraint on <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/986936bec272878d92f9c6fb0f0ce3c5b118cc0e.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />, I decided to try a DP on (position,sum) — it was a massive hint for me. Well, sometimes it just happens that there's a simple solution, which the author doesn't realize :D. Maybe this could be eliminated by some extensive "problem testing" by random capable people?</p><p>I guess I was also lucky in not trying to solve B. I solved in the order: A (because it's easy), C (because I like it), D (because it's easy) :D</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158607 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158607 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158607\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158610\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Mostafa_36a2\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/137637/avatar/28a01293a2b409.jpg'/> </a>\n <div><a href=\"/profile/Mostafa_36a2\" title=\"Specialist Mostafa_36a2\" class=\"rated-user user-cyan\">Mostafa_36a2</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 23:09\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158610\" href=\"?#comment-158610\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158610\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"-9\"\r\n data-commentUserId=\"137637\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-9</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158610\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I've found a very short solution for Div2 C , by zxz5759209</p> <pre><code>scanf("%d",&n);\n LL cnt=0,sum=0;\n for(int i=1;i<=n;i++)\n {\n scanf("%d",&x);\n cnt+=(LL)x;\n if(!x)sum+=cnt;\n }\n printf("%I64d\\n",sum);\n</code></pre></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158610 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158610 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158610\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158641\" commentParentId=\"158610\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Robert.One\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Robert.One\" title=\"Pupil Robert.One\" class=\"rated-user user-green\">Robert.One</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 01:27\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158641\" href=\"?#comment-158641\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-158610\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158641\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"150202\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158641\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I also had this solution and i got accepted but it took 1 hour to find it during the contest</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158641 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158641 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158641\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158612\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Darek_\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Darek_\" title=\"Specialist Darek_\" class=\"rated-user user-cyan\">Darek_</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 23:12\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158612\" href=\"?#comment-158612\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158612\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"152123\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158612\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks for an informative editorial.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158612 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158612 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158612\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158618\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Mostafa_36a2\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/137637/avatar/28a01293a2b409.jpg'/> </a>\n <div><a href=\"/profile/Mostafa_36a2\" title=\"Specialist Mostafa_36a2\" class=\"rated-user user-cyan\">Mostafa_36a2</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 23:25\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158618\" href=\"?#comment-158618\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"158618\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"158618\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"137637\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158618\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Unbelivable solution for Div2,B by Sick_Coder</p> <pre><code>cin >> n >> m >> k;\n cout << m * (m - 1) / 2 << "\\n";\n\n for (1, m, i)\n \tfor (i + 1, m, j)\n \t\tif (!k)\n \t\t\tcout << i << " " << j << "\\n";\n \t\telse\t\n \t\t\tcout << j << " " << i << "\\n";\n</code></pre></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158618 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158618 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158618\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158631\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mugurelionut\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/63702/avatar/45e4d5390c215090.jpg'/> </a>\n <div><a href=\"/profile/mugurelionut\" title=\"International Master mugurelionut\" class=\"rated-user user-orange\">mugurelionut</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 23:57\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158631\" href=\"?#comment-158631\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158631\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"63702\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158631\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>A very good editorial, indeed! (but please don't forget about Div1E) And the problems were really nice. But I think problem B was tougher than it should have been for its amount of points. I've read some comments saying that problem B had too weak pretests (because so many solutions failed the final system tests). I would have to say that my experience with problem B was the exact opposite. I coded two wrong solutions (which failed some pretest or another) before eventually finding and implementing the right solution. So I'd say that problem B had good pretests :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158631 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158631 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158631\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158635\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/MohammadFatafta\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/148405/avatar/4276577919b9713d.jpg'/> </a>\n <div><a href=\"/profile/MohammadFatafta\" title=\"Specialist MohammadFatafta\" class=\"rated-user user-cyan\">MohammadFatafta</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 00:11\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158635\" href=\"?#comment-158635\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158635\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"148405\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158635\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>now this is a real editorial!! thanks guys :D</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158635 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158635 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158635\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158636\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/matrix\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/matrix\" title=\"Master matrix\" class=\"rated-user user-orange\">matrix</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 00:15\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158636\" href=\"?#comment-158636\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"158636\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"158636\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"16572\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158636\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Hi,</p><p>Great and fast editorial with complete details. </p><p>Thanks very much.</p><p>Edit: I think there is a small typo: "It’s not hard to see that answer for a fixed (i1, j1) is left[i1][j1] * value[2 * j1 – sum_of_elements_from_i1]." I guess you meant count[2 * j1 – sum_of_elements_from_i1].</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158636 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158636 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158636\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158637\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Kyuubi\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/83590/avatar/b87432a652bb276.jpg'/> </a>\n <div><a href=\"/profile/Kyuubi\" title=\"Expert Kyuubi\" class=\"rated-user user-blue\">Kyuubi</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 00:18\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158637\" href=\"?#comment-158637\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158637\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"2\"\r\n data-commentUserId=\"83590\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+2</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158637\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Best Editorials I have seen on codeforces yet! :D</p><p>For Propagating tree, how do we keep track of alternating levels in the arrays we created using DFS ? </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158637 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158637 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158637\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158640\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/k_____k\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/60285/avatar/422359e1ae9d666c.jpg'/> </a>\n <div><a href=\"/profile/k_____k\" title=\"Expert k_____k\" class=\"rated-user user-blue\">k_____k</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 01:07\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158640\" href=\"?#comment-158640\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158640\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"2\"\r\n data-commentUserId=\"60285\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+2</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158640\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Best Editorials Ever ! #thanks to the authors, for posting alternative solutions of contestants also. Great start in 2014. #Looking Forward.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158640 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158640 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158640\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158658\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/sillycross\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/41652/avatar/58966d0c793c6394.jpg'/> </a>\n <div><a href=\"/profile/sillycross\" title=\"Grandmaster sillycross\" class=\"rated-user user-red\">sillycross</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 07:49\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158658\" href=\"?#comment-158658\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158658\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"9\"\r\n data-commentUserId=\"41652\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+9</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158658\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Div1 E can be solved in O(2^24*24) or O(2^24+2^12*n)..</p><p>O(2^24*24): dp[i][s] means the sum of all contributions of subset s where all digits are same as s except the last i digits.. </p><p>O(2^24+2^12*n): the length of word is only 3. We divide the 24 letters in half, calculate the answer for all first 12 letters and all last 12 letters and merge them with brute-force. This can be solved in O(2^24). Then we subtract the words that are counted twice: these words are words that have 2 letters in first half and 1 in second half, or 2 in second half and 1 in first half. Let's consider the first case: for each subset of first 12 letters we check each word whether it has exactly 2 letters in this half, if so, we can say all masks in another half that contains the third letter need to be subtracted by 1. This can be solved in 2^12*(2^12+n). Same algorithm can be used to solve the second case. Although this algorithm runs slower than O(2^24*24) bcuz of its larger constant... </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158658 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158658 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158658\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158663\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/VeniVidiVici\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/VeniVidiVici\" title=\"Candidate Master VeniVidiVici\" class=\"rated-user user-violet\">VeniVidiVici</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 09:39\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158663\" href=\"?#comment-158663\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158663\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"149163\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158663\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Very nice editorial! Disappointed in Div 2B though, really expected the "real" problem rather than just insertion sort but that's what you get for not reading carefully ;)</p><p>However, does anyone have an accepted solution that is "real" (e.g. finds the minimum number of operations necessary and prints such a solution)? I was close but my computer died during contest and I haven't tried so much since (of course you can do O((mn)^2) easily but this is way too slow, there should be a O(n*m^2) solution but again my computer was unable to operate). My approach was to make 2-D boolean array to check if a swap is necessary, but I'm not sure if order of operations will end up being a big problem.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158663 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158663 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158663\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158685\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/LegendaryGrandmaster\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/142091/avatar/a3a5a4b5c26ac419.jpg'/> </a>\n <div><a href=\"/profile/LegendaryGrandmaster\" title=\"Specialist LegendaryGrandmaster\" class=\"rated-user user-cyan\">LegendaryGrandmaster</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 14:34\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158685\" href=\"?#comment-158685\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158685\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"142091\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158685\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>One of the best codeforces editorials ever! Thanks!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158685 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158685 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158685\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158687\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/BENYAM1N\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/84938/avatar/d2ae2657d8898e38.jpg'/> </a>\n <div><a href=\"/profile/BENYAM1N\" title=\"Master BENYAM1N\" class=\"rated-user user-orange\">BENYAM1N</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 15:24\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158687\" href=\"?#comment-158687\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"158687\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"158687\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"84938\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158687\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks a lot. very good contest and good editorial too!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158687 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158687 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158687\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158689\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/JuanMata\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/82548/avatar/a7d69af7b441c6d7.jpg'/> </a>\n <div><a href=\"/profile/JuanMata\" title=\"Expert JuanMata\" class=\"rated-user user-blue\">JuanMata</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 15:47\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158689\" href=\"?#comment-158689\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158689\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"82548\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158689\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>this is one of the best editorials on CF ever!!!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158689 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158689 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158689\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158700\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Vicfred\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/76941/avatar/d067b7433ec39337.jpg'/> </a>\n <div><a href=\"/profile/Vicfred\" title=\"Pupil Vicfred\" class=\"rated-user user-green\">Vicfred</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 16:25\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158700\" href=\"?#comment-158700\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158700\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"11\"\r\n data-commentUserId=\"76941\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+11</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158700\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>The best editorial I've read in a while here, thanks.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158700 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158700 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158700\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158727\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/beecoder\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/beecoder\" title=\"Pupil beecoder\" class=\"rated-user user-green\">beecoder</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 21:13\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158727\" href=\"?#comment-158727\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158727\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"89551\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158727\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Hi, The way I print answers for 'Coder Problem' is as follows. This takes 124 ms. is there a way to print the answers faster ? </p> <pre><code> \tfor (int i = 0 ; i < number ; i ++ ) { \n \t\tfor (int k = 0 ; k < number ; k ++ ) { \n \t\t\tif (flag) {\n \t\t\t\tif ( k % 2 == 1) out.print('.');\n \t\t\t\tif( k% 2 == 0 ) out.print('C');\n \t\t\t} else {\n \t\t\tif ( k % 2 == 1) out.print('C');\n \t\t\tif( k% 2 == 0 ) out.print('.');\t\n \t\t\t}\n \t\t}\n \t\tif (flag) flag = false;\n \t\telse flag = true;\n \t\tout.print("\\n");\n \t}\n \n</code></pre></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158727 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158727 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158727\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158742\" commentParentId=\"158727\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Mostafa_36a2\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/137637/avatar/28a01293a2b409.jpg'/> </a>\n <div><a href=\"/profile/Mostafa_36a2\" title=\"Specialist Mostafa_36a2\" class=\"rated-user user-cyan\">Mostafa_36a2</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/22/2014 14:00\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158742\" href=\"?#comment-158742\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-158727\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158742\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"137637\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158742\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>As the line contains k characters , and every odd lines are identical , also the even ones,</p><p>you can build 2 strings [C.C.C.C] and [.C.C.C.] and print them alternately </p><p>[In my opinion Java is slow language any way ]</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158742 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158742 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158742\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158752\" commentParentId=\"158727\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/t_thirupathi\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/146179/avatar/98c28348196ce4ca.jpg'/> </a>\n <div><a href=\"/profile/t_thirupathi\" title=\"Specialist t_thirupathi\" class=\"rated-user user-cyan\">t_thirupathi</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/22/2014 18:19\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158752\" href=\"?#comment-158752\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-158727\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158752\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"146179\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158752\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Modulo operations are time consuming.</p><p>To check if a number <code>n</code> is odd, you could use <code>if (n & 1)</code></p> <pre><code>for (int i = 0; i < n; i++) {\n for (int j = 0; j < n; j++)\n if ((i + j) & 1)\n out.print('.');\n else \n out.print('C');\n out.print('\\n');\n}\n</code></pre></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158752 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158752 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158752\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158745\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/JuanMata\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/82548/avatar/a7d69af7b441c6d7.jpg'/> </a>\n <div><a href=\"/profile/JuanMata\" title=\"Expert JuanMata\" class=\"rated-user user-blue\">JuanMata</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/22/2014 14:49\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158745\" href=\"?#comment-158745\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"158745\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"158745\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"82548\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158745\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>i think there is a small bug in the <a href=\"http://pastie.org/8651824\">pastie link</a> u posted for the solution of Div1 C problem.</p><p>i submitted almost exact copy of it (<a href=\"/contest/383/submission/5769615\" title=\"Submission 5769615 by JuanMata\">5769615</a>), but got WA#6. then i found the bug, corrected it and resubmitted (<a href=\"/contest/383/submission/5769890\" title=\"Submission 5769890 by JuanMata\">5769890</a>) and got AC.</p><p>referring to my two submissions, corrections in line <strong>68</strong> (last statement of <strong>dfs</strong>) and line <strong>109</strong> (the second call to <strong>update</strong>).</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158745 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158745 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158745\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"615836\" commentParentId=\"158745\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/adityakr007\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/adityakr007\" title=\"Expert adityakr007\" class=\"rated-user user-blue\">adityakr007</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/05/2020 18:54\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-615836\" href=\"?#comment-615836\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-158745\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"615836\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"866209\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-615836\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can you explain what exactly have you done in your submission (<a href=\"/contest/383/submission/5769890\" title=\"Submission 5769890 by JuanMata\">5769890</a>) for this problem?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-615836 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-615836 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-615836\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"629531\" commentParentId=\"615836\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/JuanMata\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/82548/avatar/a7d69af7b441c6d7.jpg'/> </a>\n <div><a href=\"/profile/JuanMata\" title=\"Expert JuanMata\" class=\"rated-user user-blue\">JuanMata</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/25/2020 18:14\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-629531\" href=\"?#comment-629531\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-615836\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"629531\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"82548\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-629531\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>sorry bro i've forgotten ... that was over 6yrs ago now!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-629531 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-629531 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-629531\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158751\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/TempuX\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/30820/avatar/c50adc243ea4e2fa.jpg'/> </a>\n <div><a href=\"/profile/TempuX\" title=\"Specialist TempuX\" class=\"rated-user user-cyan\">TempuX</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/22/2014 17:07\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158751\" href=\"?#comment-158751\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158751\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"30820\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158751\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Hi, I tried to implement the Volcano problem in the way explained in the editorial but I'm getting TLE. Here is my code <a href=\"//codeforces.com/contest/384/submission/5770818\">submission</a> What am I doing wrong ? Thanks anyway.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158751 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158751 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158751\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158811\" commentParentId=\"158751\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/TempuX\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/30820/avatar/c50adc243ea4e2fa.jpg'/> </a>\n <div><a href=\"/profile/TempuX\" title=\"Specialist TempuX\" class=\"rated-user user-cyan\">TempuX</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/23/2014 17:29\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158811\" href=\"?#comment-158811\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-158751\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158811\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"30820\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158811\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Turns out my binary search is causing the problem and I don't see what is wrong with it... I would appreciate any ideas.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158811 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158811 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158811\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159025\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/bboy_drain\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/76710/avatar/e0feb3aa135911d4.jpg'/> </a>\n <div><a href=\"/profile/bboy_drain\" title=\"Expert bboy_drain\" class=\"rated-user user-blue\">bboy_drain</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/25/2014 01:34\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159025\" href=\"?#comment-159025\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159025\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"76710\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159025\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Wow! This really helped me a lot! Very detailed explanations!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159025 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159025 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159025\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159092\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/AlexandruValeanu\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/131651/avatar/1c7d989c45052941.jpg'/> </a>\n <div><a href=\"/profile/AlexandruValeanu\" title=\"Candidate Master AlexandruValeanu\" class=\"rated-user user-violet\">AlexandruValeanu</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/25/2014 21:27\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159092\" href=\"?#comment-159092\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159092\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"131651\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159092\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>It was by far your best round on Codeforces, <a class=\"rated-user user-blue\" href=\"/profile/fchirica\" title=\"Expert fchirica\">fchirica</a>. The problems were great, very different one from the other and some of them didn't require any algorithmic skills at all. Good job!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159092 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159092 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159092\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159261\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lawsonh\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/lawsonh\" title=\"Expert lawsonh\" class=\"rated-user user-blue\">lawsonh</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/28/2014 06:33\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159261\" href=\"?#comment-159261\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"159261\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"159261\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"55047\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159261\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>for div1 383C should end[5] = 7? edit: nvm drew the tree wrong</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159261 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159261 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159261\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159474\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/tiagonapoli\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/150060/avatar/6615fcab66b23361.jpg'/> </a>\n <div><a href=\"/profile/tiagonapoli\" title=\"Candidate Master tiagonapoli\" class=\"rated-user user-violet\">tiagonapoli</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/30/2014 22:28\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159474\" href=\"?#comment-159474\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159474\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"150060\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159474\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Great Editorial! Thanks so much, i've learned a lot!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159474 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159474 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159474\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159707\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lchf\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/60496/avatar/e9939e755252ec16.jpg'/> </a>\n <div><a href=\"/profile/lchf\" title=\"Candidate Master lchf\" class=\"rated-user user-violet\">lchf</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/02/2014 17:28\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159707\" href=\"?#comment-159707\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159707\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"60496\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159707\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Amazing solution by Endagorion.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159707 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159707 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159707\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"177400\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/sourabh912\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/57335/avatar/bf83b9340e3cbb17.jpg'/> </a>\n <div><a href=\"/profile/sourabh912\" title=\"Specialist sourabh912\" class=\"rated-user user-cyan\">sourabh912</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/12/2014 20:39\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-177400\" href=\"?#comment-177400\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"177400\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"57335\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-177400\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In Div 1C problem, I could not understand how it can be solved using single fenwick tree from the solution link in the editorial. Can anyone please help.</p><p>Thanks</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-177400 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-177400 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-177400\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"291157\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/l_Love_KFC\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/258117/avatar/bbaec3ce1613f5bd.jpg'/> </a>\n <div><a href=\"/profile/l_Love_KFC\" title=\"Expert l_Love_KFC\" class=\"rated-user user-blue\">l_Love_KFC</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Apr/29/2016 08:23\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-291157\" href=\"?#comment-291157\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"291157\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"258117\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-291157\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In Div.1 A I didn't catch the point that in 1st, quote : "If we put i before j, no additional cost will be added. Since j is in right of i and i only adds cost when it finds elements in left of i, j won’t be affected when processing i." Won't we lose milk if we put firstly i, in case of that j sees that and loses milk? Or am I misunderstanding the task? </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-291157 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-291157 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-291157\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"309434\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/haleyk100198\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/416324/avatar/f2d97d505af17e9d.jpg'/> </a>\n <div><a href=\"/profile/haleyk100198\" title=\"Candidate Master haleyk100198\" class=\"rated-user user-violet\">haleyk100198</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/11/2016 06:32\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-309434\" href=\"?#comment-309434\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"309434\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"416324\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-309434\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I wonder how the problem Div1C can be converted to a segment tree lazy propagation implementation question, for trees like (1-2 2-3 3-4 4-5 .... 9999-E4) how can we achieve O(log N) update time?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-309434 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-309434 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-309434\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"310847\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/my_new_handle\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/233736/avatar/24128c61b65e3262.jpg'/> </a>\n <div><a href=\"/profile/my_new_handle\" title=\"Candidate Master my_new_handle\" class=\"rated-user user-violet\">my_new_handle</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/20/2016 14:49\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-310847\" href=\"?#comment-310847\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"310847\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"233736\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-310847\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>а зачем в таске б массив он влияет как-то?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-310847 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-310847 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-310847\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"332763\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/rhezo\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/305605/avatar/aa59e9c2ec688c6a.jpg'/> </a>\n <div><a href=\"/profile/rhezo\" title=\"Candidate Master rhezo\" class=\"rated-user user-violet\">rhezo</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Dec/24/2016 07:56\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-332763\" href=\"?#comment-332763\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"332763\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"305605\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-332763\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I'm getting Runtime Error on test 44 in <a href=\"//codeforces.com/problemset/problem/383/C\">Propogating Tree</a>. </p><p>This is because of stack overflow right? That test has N = 2e5 and for a straight chain of nodes, I'll get a runtime error with a recursive DFS right? What to do in such cases? </p><p>I can write an iterative DFS, but I do HLD recursively too and I'm not quite sure if I can write an iterative HLD. </p><p>Can anyone tell me what to do in such cases? I'm assuming that I got the runtime error due to stackoverflow from DFS.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-332763 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-332763 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-332763\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"346070\" commentParentId=\"332763\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/yinanzhu\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/520731/avatar/d61a58bf5df54146.jpg'/> </a>\n <div><a href=\"/profile/yinanzhu\" title=\"Expert yinanzhu\" class=\"rated-user user-blue\">yinanzhu</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/26/2017 07:18\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-346070\" href=\"?#comment-346070\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-332763\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"346070\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"520731\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-346070\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I used recursive dfs and passed all test case. Test 44 cost 1.5 s</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-346070 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-346070 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-346070\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"387028\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/blue__legend\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/blue__legend\" title=\"Expert blue__legend\" class=\"rated-user user-blue\">blue__legend</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/23/2017 07:16\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-387028\" href=\"?#comment-387028\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"387028\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"284949\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-387028\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>How to solve DIV 1 C using one fenwick or segment tree. The code link given in editorial is not working.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-387028 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-387028 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-387028\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"757423\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Ausmosian\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Ausmosian\" title=\"Expert Ausmosian\" class=\"rated-user user-blue\">Ausmosian</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/05/2021 15:05\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-757423\" href=\"?#comment-757423\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"757423\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"727283\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-757423\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>[<a href=\"https://codeforces.com/contest/383/problem/C\">384E — Propagating tree</a>] Can also be solved using Square Root Decomposition. <a href=\"https://codeforces.com/contest/383/submission/106526543\">Submission</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-757423 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-757423 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-757423\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"838255\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/3hill\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1621900/avatar/478297db63bad207.jpg'/> </a>\n <div><a href=\"/profile/3hill\" title=\"Expert 3hill\" class=\"rated-user user-blue\">3hill</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/11/2021 17:02\">2 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-838255\" href=\"?#comment-838255\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"838255\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1621900\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-838255\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I am Getting MLE on TC-53<br />Can someone review my code and figure out the issue ,Thanks</p> <ul> <li><a href=\"https://codeforces.com/contest/383/problem/C\">Problem</a></li> <li><a href=\"https://codeforces.com/contest/383/submission/128510633\">My code</a></li> </ul></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-838255 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-838255 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-838255\">\r\n </ul>\r\n</div>\r\n <br/>\r\n\r\n<div id=\"editBox-10547\" style=\"width:50em;display:none;\">\r\n <div class=\"previewBody\" style=\"border: 1px solid #d4d4d4; margin-bottom: 0.5em; padding: 0.25em; display:none;\"> </div>\r\n <div style=\"width: 1px\"> </div>\r\n <div class=\"commentLocale\" style=\"position: relative; top: 0.5em;left:4px;display: none;\">\r\n <input type=\"radio\" name=\"locale\" value=\"en\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In English</span>\r\n <input style=\"margin-left:1em\" type=\"radio\" name=\"locale\" value=\"ru\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In Russian</span>\r\n </div>\r\n <textarea data-drafts-id=\"CommentReplyFrame\" class=\"wysiwyg\" name=\"editContent\" rows=\"20\" style=\"width:99%;\"></textarea>\r\n <div class=\"error error__content\"></div>\r\n <div style=\"text-align:center;\">\r\n <input type=\"button\" name=\"preview\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Preview\"/>\r\n <input type=\"button\" name=\"save\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Save\"/>\r\n </div>\r\n</div>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n\r\nvar firstPreview10547 = true;\r\nvar lastPreviewContent10547 = '';\r\n\r\nif (!window.moveCommentRevision) {\r\n moveCommentRevision = function(e, dir) {\r\n var p = e.parent();\r\n var revisionCount = parseInt(p.attr(\"revisionCount\"));\r\n var revision = parseInt(p.attr(\"revision\"));\r\n var next = revision + dir;\r\n var commentId = p.attr(\"commentId\");\r\n if (next >= 1 && next <= revisionCount) {\r\n $.post(\r\n \"/data/comment-data\",\r\n {action: \"revision\", commentId: commentId, revision: next},\r\n function(json) {\r\n if (json.success == \"true\") {\r\n var parentDiv = e;\r\n\r\n while (parentDiv !== null && (parentDiv[0].nodeName.toLowerCase() !== \"td\" || !parentDiv.hasClass(\"right\"))) {\r\n parentDiv = parentDiv.parent();\r\n }\r\n\r\n if (parentDiv === null) {\r\n return;\r\n }\r\n\r\n parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\").html(json.content);\r\n Codeforces.setupSpoilers(parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\"));\r\n p.attr(\"revision\", next);\r\n p.find(\"span.revision\").text(next);\r\n if (next == 1) {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"visible\");\r\n }\r\n if (next == revisionCount) {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"visible\");\r\n }\r\n\r\n window.updateTypography();\r\n MathJax.Hub.Typeset();\r\n } else {\r\n alert(e.error);\r\n }\r\n },\r\n \"json\"\r\n );\r\n }\r\n };\r\n}\r\n\r\n$(\"div[commentableId=10547] a.leftRevision\").click(function () {\r\n window.moveCommentRevision($(this), -1);\r\n return false;\r\n});\r\n\r\n$(\"div[commentableId=10547] a.rightRevision\").click(function () {\r\n window.moveCommentRevision($(this), +1);\r\n return false;\r\n});\r\n\r\n\r\n\r\n });\n </script>\n\r\n\r\n <script src=\"//codeforces.org/s/81027/js/swfobject-2.2.min.js\" type=\"text/javascript\"></script>\n <script src=\"//codeforces.org/s/81027/js/ftaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n if (window.evercookie) {\n var ec = new evercookie({\n history: false,\n silverlight: false,\n baseurl: '',\n asseturi: '/assets',\n phpuri: '/2fdcd78',\n pngPath: '/eps',\n etagPath: '/ees',\n cachePath: '/ecs'\n });\n\n var randomNumber = function () {\n return Math.random().toString(36).substr(2);\n };\n\n var randomToken = function () {\n return (randomNumber() + randomNumber()).substring(0, 18);\n };\n\n window._ftaa = \"\";\n\n ec.get(\"70a7c28f3de\", function (value) {\n window._ftaa = value;\n if (!window._ftaa) {\n window._ftaa = randomToken();\n ec.set(\"70a7c28f3de\", window._ftaa);\n }\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n } else {\n window._ftaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\n <script src=\"//codeforces.org/s/81027/js/bfaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n var fpCallback = function() {\n Fingerprint2.get({}, function(components) {\n window._bfaa = Fingerprint2.x64hash128(components.map(function (pair) { return pair.value }).join(), 31);\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n };\n if (typeof Fingerprint2 !== 'undefined') {\n if (window.requestIdleCallback) {\n requestIdleCallback(fpCallback)\n } else {\n setTimeout(fpCallback, 500)\n }\n } else {\n window._bfaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"a.new-root-comment\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n\r\n $(\".comment-table .reply a\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".vote-for-comment\").mouseover(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").mouseout(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").click(function () {\r\n var vote = $(this);\r\n var commentId = $(this).parent().attr(\"commentid\");\r\n var commentRating = $(this).parent().attr(\"data-commentRating\");\r\n var direction = $(this).attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n $.post(\"/data/comment/vote\", {commentId: commentId, _tta: Codeforces.tta(), vote: direction, commentRating: commentRating}, function(data) {\r\n if (direction != 0 && !ownComment && data[\"success\"] == \"true\") {\r\n vote.parent().find(\".vote-for-comment\").attr(\"voteDirection\", 0);\r\n if (direction == 1)\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n else {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.closest(\".CommentVoteFrame\").find(\".ComplaintFrame\").css(\"display\", \"inline-block\");\r\n }\r\n vote.find(\"img\").attr(\"popacity\", \"1.0\");\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n vote.parent().find(\".commentRating\").html(data[\"commentRating\"]);\r\n }\r\n Codeforces.showMessage(data[\"message\"]);\r\n }, \"json\");\r\n return false;\r\n });\r\n\r\n $(\".negative-comment-vote\").closest(\".comment-table\").addClass(\"comment-bad\");\r\n\r\n $(\".troll-comment-vote\").closest(\".comment\").css(\"display\", \"none\");\r\n\r\n $(\".too-negative-comment-vote\").closest(\".comment-table\").each(function () {\r\n var e = $(this);\r\n e.addClass(\"comment-too-bad\");\r\n var commentId = e.attr(\"commentId\");\r\n $(\"<div class='bad-comment-replacement ttypography'>The comment is hidden because of too negative feedback, click <a href=# class=show-bad-comment-link>here</a> to view it</div>\").appendTo(\r\n e.find(\".right\")\r\n );\r\n e.find(\".comment-content\").hide();\r\n e.find(\".show-bad-comment-link\").click(function () {\r\n e.find(\".comment-content\").show();\r\n e.find(\".bad-comment-replacement\").hide();\r\n return false;\r\n });\r\n });\r\n });\n </script>\n </div>\r\n\r\n <style type=\"text/css\">\r\n .new-comments-box {\r\n padding: 0.5em;\r\n width: 22px;\r\n font-size: 1.3rem;\r\n font-weight: bold !important;\r\n\r\n position: fixed;\r\n top: 40%;\r\n right: 0;\r\n opacity: 0.2;\r\n color: white;\r\n text-align: center;\r\n\r\n border: 1px solid #222;\r\n background-color: #888 !important;\r\n border-radius: 3px;\r\n -moz-border-radius: 3px;\r\n -webkit-border-radius: 3px;\r\n }\r\n\r\n .new-comments-box:hover {\r\n opacity: 1;\r\n }\r\n\r\n .new-comments-box .dir:hover {\r\n background: #3B5998 !important;\r\n cursor: pointer;\r\n }\r\n </style>\r\n\r\n <div class=\"new-comments-box\" data-position=\"outside\" data-index=\"-1\" style=\"display: none;\">\r\n <div class=\"up dir\" title=\"Ctrl+Up\">↑<hr/>\r\n </div>\r\n <div class=\"info\" title=\"New comments\"></div>\r\n <div class=\"down dir\" title=\"Ctrl+Down\">\r\n <hr/>↓\r\n </div>\r\n </div>\r\n\r\n <script>\r\n $(\".show-archived-checkbox\").change(function () {\r\n const checked = $(this).is(\":checked\");\r\n $.post(\"/data/comment-data\", {action: \"setShowArchived\", checked}, function (json) {\r\n if (json[\"success\"] !== \"true\") {\r\n alert(json[\"error\"]);\r\n } else {\r\n if (checked) {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are now displayed\")\r\n } else {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are no longer displayed\")\r\n }\r\n }\r\n });\r\n return false;\r\n });\r\n\r\n function gotoComment(direction) {\r\n var box = $(\".new-comments-box\");\r\n var index = parseInt(box.attr(\"data-index\"));\r\n if (index == -1)\r\n index = 0;\r\n else\r\n index = Math.max(0, Math.min(parseInt(box.find(\".info\").text()) - 1, index + direction));\r\n box.attr(\"data-index\", index);\r\n var comment = $($(\".comment .highlight-blue[commentId]\").get(index));\r\n $('html, body').animate({\r\n 'scrollTop': Math.max(0, comment.offset().top - ($(window).height() - comment.height()) / 2)\r\n });\r\n return false;\r\n }\r\n\r\n $(\".new-comments-box .down\").click(function () {\r\n return gotoComment(1);\r\n });\r\n\r\n $(\".new-comments-box .up\").click(function () {\r\n return gotoComment(-1);\r\n });\r\n\r\n $(document).keydown(function (e) {\r\n var code = (e.keyCode ? e.keyCode : e.which);\r\n if (e.ctrlKey) {\r\n if (code == 38 || code == 40) {\r\n gotoComment(code - 39);\r\n }\r\n }\r\n });\r\n\r\n var newCommentCount = $(\".comment .highlight-blue[commentId]\").length;\r\n if (newCommentCount > 0) {\r\n $(\".new-comments-box .info\").text(newCommentCount);\r\n $(\".new-comments-box\").show();\r\n }\r\n\r\n $('table.comment-table').mouseenter(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").addClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n\r\n $('table.comment-table').mouseleave(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").removeClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n </script>\r\n\r\n\r\n\r\n <script>\r\n function adjustTopicComplainFrames() {\r\n let topicIds = [];\r\n\r\n $(\".has-topic-id\").each(function () {\r\n const $this = $(this);\r\n const topicId = $this.attr(\"topicId\");\r\n if (topicId) {\r\n topicIds.push(topicId);\r\n }\r\n });\r\n\r\n $.post(\"/data/topics\", {\r\n action: \"findComplainableTopicIds\",\r\n topicIds: topicIds.join(\",\")\r\n }, function (json) {\r\n if (json[\"success\"] === \"true\") {\r\n for (const topicId of json[\"complainableTopicIds\"].split(\",\")) {\r\n $(\".has-topic-id[topicId=\" + topicId + \"]\").each(function () {\r\n $(this).find(\".meta .ComplaintFrame\").css(\"display\", \"inline-block\");\r\n });\r\n }\r\n }\r\n }, \"json\");\r\n }\r\n\r\n $(function () {\r\n adjustTopicComplainFrames();\r\n })\r\n </script>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-10531\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 10531, _tta: Codeforces.tta(), topicRevisionId: 36233, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-10531\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 10531, _tta: Codeforces.tta(), topicRevisionId: 36233, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n </div>\r\n </div>\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 22:13:02</span> (h1).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/81027/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/81027/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/81027/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/81027/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-81027.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'81287584a8369d92',t:'MTY5NjcwNTk4Mi42NDcwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"}}},{"rowIdx":1942,"cells":{"problem_id":{"kind":"string","value":"384D"},"contest":{"kind":"string","value":"384"},"problem":{"kind":"string","value":"D"},"lang":{"kind":"string","value":"en"},"problem_title":{"kind":"string","value":"D. Volcanoes"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">D. Volcanoes</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Iahub got lost in a very big desert. The desert can be represented as a <span class=\"tex-span\"><i>n</i> × <i>n</i></span> square matrix, where each cell is a zone of the desert. The cell <span class=\"tex-span\">(<i>i</i>, <i>j</i>)</span> represents the cell at row <span class=\"tex-span\"><i>i</i></span> and column <span class=\"tex-span\"><i>j</i></span> <span class=\"tex-span\">(1 ≤ <i>i</i>, <i>j</i> ≤ <i>n</i>)</span>. Iahub can go from one cell <span class=\"tex-span\">(<i>i</i>, <i>j</i>)</span> only down or right, that is to cells <span class=\"tex-span\">(<i>i</i> + 1, <i>j</i>)</span> or <span class=\"tex-span\">(<i>i</i>, <i>j</i> + 1)</span>. </p><p>Also, there are <span class=\"tex-span\"><i>m</i></span> cells that are occupied by volcanoes, which Iahub cannot enter. </p><p>Iahub is initially at cell <span class=\"tex-span\">(1, 1)</span> and he needs to travel to cell <span class=\"tex-span\">(<i>n</i>, <i>n</i>)</span>. Knowing that Iahub needs <span class=\"tex-span\">1</span> second to travel from one cell to another, find the minimum time in which he can arrive in cell <span class=\"tex-span\">(<i>n</i>, <i>n</i>)</span>.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains two integers <span class=\"tex-span\"><i>n</i></span> <span class=\"tex-span\">(1 ≤ <i>n</i> ≤ 10<sup class=\"upper-index\">9</sup>)</span> and <span class=\"tex-span\"><i>m</i></span> <span class=\"tex-span\">(1 ≤ <i>m</i> ≤ 10<sup class=\"upper-index\">5</sup>)</span>. Each of the next <span class=\"tex-span\"><i>m</i></span> lines contains a pair of integers, <span class=\"tex-span\"><i>x</i></span> and <span class=\"tex-span\"><i>y</i></span> <span class=\"tex-span\">(1 ≤ <i>x</i>, <i>y</i> ≤ <i>n</i>)</span>, representing the coordinates of the volcanoes.</p><p>Consider matrix rows are numbered from 1 to <span class=\"tex-span\"><i>n</i></span> from top to bottom, and matrix columns are numbered from 1 to <span class=\"tex-span\"><i>n</i></span> from left to right. There is no volcano in cell <span class=\"tex-span\">(1, 1)</span>. No two volcanoes occupy the same location. </p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print one integer, the minimum time in which Iahub can arrive at cell <span class=\"tex-span\">(<i>n</i>, <i>n</i>)</span>. If no solution exists (there is no path to the final cell), print -1.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>4 2<br/>1 3<br/>1 4<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>6<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>7 8<br/>1 6<br/>2 6<br/>3 5<br/>3 6<br/>4 3<br/>5 1<br/>5 2<br/>5 3<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>12<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>2 2<br/>1 2<br/>2 1<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>-1<br/></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>Consider the first sample. A possible road is: <span class=\"tex-span\">(1, 1)</span> <span class=\"tex-span\"> → </span> <span class=\"tex-span\">(1, 2)</span> <span class=\"tex-span\"> → </span> <span class=\"tex-span\">(2, 2)</span> <span class=\"tex-span\"> → </span> <span class=\"tex-span\">(2, 3)</span> <span class=\"tex-span\"> → </span> <span class=\"tex-span\">(3, 3)</span> <span class=\"tex-span\"> → </span> <span class=\"tex-span\">(3, 4)</span> <span class=\"tex-span\"> → </span> <span class=\"tex-span\">(4, 4)</span>.</p></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"cc084530abcb7357ef296db584a697e1\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - D - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"2080925ccc752dc6d7cc9e06390b1986ca0eae39\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - D - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/73366/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/73366/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/73366/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/73366/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/73366/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/73366/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/73366/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/73366/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/73366/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/73366/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/73366/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/73366/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/73366/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/73366/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/sidebar-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/a037fe51637846d9c7c725713cd840ea/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='cc084530abcb7357ef296db584a697e1'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/73366/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/73366/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fcontest%2F384%2Fproblem%2FD%3Flocale%3Den\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"current\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='cc084530abcb7357ef296db584a697e1'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:100%;\"><a style=\"color: black\" href=\"/contest/384\">Codeforces Round 225 (Div. 2)</a></th>\n </tr>\n <tr>\n <td class=\"left bottom\" colspan=\"1\"><span class=\"contest-state-phase\">Finished</span></td>\n </tr>\n </tbody>\n </table>\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Practice?\n <div class=\"top-links\">\n </div>\n </div>\n<div>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Want to solve the contest problems after the official contest ends? Just register for practice and you will be able to submit solutions.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"\" method=\"post\"><input type='hidden' name='csrf_token' value='cc084530abcb7357ef296db584a697e1'/>\r\n <input type=\"hidden\" name=\"action\" value=\"registerForPractice\"/>\r\n <input type=\"submit\" name=\"submit\" value=\"Register for practice\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div> \r\n</div>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox ContestVirtualFrame borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Virtual participation <i class=\"sidebar-caption-icon las la-angle-down\"></i>\r\n\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\" \"\r\n\r\n data-page-url=\"/data/sidebarFrames\"\r\n\r\n>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests.\n\nIf you've seen these problems, a virtual contest is not for you - solve these problems in the archive.\n\nIf you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.\n\nNever use someone else's code, read the tutorials or communicate with other person during a virtual contest.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"/contest/384/virtual\" method=\"get\">\r\n <input type=\"submit\" name=\"submit\" value=\"Start virtual contest\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div>\r\n</div>\r\n <script>\r\n $(function () {\r\n $(\".ContestVirtualFrame .sidebar-caption-icon\").click(function() {\r\n $(this).toggleClass(\"la-angle-down la-angle-right\");\r\n const $target = $(this).parent().next();\r\n $target.toggle();\r\n const dataPageUrl = $target.attr(\"data-page-url\");\r\n const collapsed = $(this).hasClass(\"la-angle-right\");\r\n const params = {\r\n action: \"setCollapsed\",\r\n sidebarFrameSimpleClassName: \"ContestVirtualFrame\",\r\n collapsed\r\n };\r\n $.each($target[0].attributes, function(i, a) {\r\n const name = a.name;\r\n if (name.startsWith(\"data-extra-key-\")) {\r\n const key = a.value;\r\n const keyIndex = parseInt(name.substring(\"data-extra-key-\".length));\r\n const value = $target.attr(\"data-extra-value-\" + keyIndex);\r\n params[key] = value;\r\n }\r\n });\r\n $.post(dataPageUrl, params, function (result) {\r\n if (result[\"success\"] !== \"true\") {\r\n Codeforces.showMessage(\"Failed to save collapsed state.\");\r\n }\r\n }, \"json\");\r\n return false;\r\n });\r\n })\r\n </script>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Problem tags\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Implementation problems, programming technics, simulation\">\r\n implementation\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Difficulty\">\r\n *2500\r\n</span>\r\n </div>\n <div style=\"clear:both;text-align:right;font-size:1.1rem;\">\r\n <span title=\"Please login into the Codeforces\" class=\"notice\">No tag edit access</span>\r\n </div>\r\n</div>\r\n </div>\n\r\n<form id=\"addTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='cc084530abcb7357ef296db584a697e1'/>\r\n <input name=\"action\" type=\"hidden\" value=\"addTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"5720\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<form id=\"removeTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='cc084530abcb7357ef296db584a697e1'/>\r\n <input name=\"action\" type=\"hidden\" value=\"removeTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"5720\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<script type=\"text/javascript\">\r\n $(\".tag-box img\").click(function () {\r\n var tagName = $(this).attr(\"value\");\r\n Codeforces.confirm(\"Are you sure you want to remove this tag?\", function () {\r\n $(\"#removeTagForm input[name=tagName]\").val(tagName);\r\n $(\"#removeTagForm\").submit();\r\n }, function () {\r\n }, \"Yes\", \"No\");\r\n });\r\n\r\n $(\"#addTagLink\").click(function () {\r\n $(this).hide();\r\n $(\"#addTagLabel\").show();\r\n return false;\r\n });\r\n\r\n $(\"#addTagSelect\").change(function () {\r\n var tagName = $(this).val();\r\n if (tagName === \"\") {\r\n $(\"#addTagLabel\").hide();\r\n $(\"#addTagLink\").show();\r\n } else {\r\n $(\"#addTagForm input[name=tagName]\").val(tagName);\r\n $(\"#addTagForm\").submit();\r\n }\r\n });\r\n</script>\r\n\r\n<style type=\"text/css\">\r\n#new-resource-form tr td {\r\npadding-top: 0.5em;\r\n}\r\n#new-resource-form input:not([type=\"submit\"]) {\r\nfont-size: 0.8em;\r\n}\r\n#new-resource-form select {\r\nfont-size: 0.8em;\r\n}\r\n.new-resource-error {\r\nfont-size: 0.8em;\r\n}\r\n.resource-locale {\r\ncolor: #666;\r\nfont-family: Consolas, \"Andale Mono WT\", \"Andale Mono\", \"Lucida Console\", \"Lucida Sans Typewriter\", \"DejaVu Sans Mono\", \"Bitstream Vera Sans Mono\", \"Liberation Mono\", \"Nimbus Mono L\", Monaco, \"Courier New\", Courier, monospace;\r\n}\r\n</style>\r\n<div class=\"roundbox sidebox sidebar-menu borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Contest materials\n<div class=\"top-links\">\n</div>\n</div>\n<ul>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/10448\" title=\"Codeforces Round #225\" target=\"_blank\">Codeforces Round #225</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"2168:2169\" resourceName=\"Announcement\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/10476\" title=\"Codeforces Round #225 — Editorial\" target=\"_blank\">Tutorial <span class=\"resource-locale\">(en)</span></a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"2173\" resourceName=\"Codeforces Round #225 — Editorial\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n</ul>\r\n</div></div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li class=\"current selectedLava\"><a\r\n href=\"/contest/384\">Problems</a></li>\r\n <li><a\r\n href=\"/contest/384/submit\">Submit Code</a></li>\r\n <li><a\r\n href=\"/contest/384/my\">My Submissions</a></li>\r\n <li><a\r\n href=\"/contest/384/status\">Status</a></li>\r\n <li><a\r\n href=\"/contest/384/hacks\">Hacks</a></li>\r\n <li><a\r\n href=\"/contest/384/room/1\">Room</a></li>\r\n <li><a\r\n href=\"/contest/384/standings\">Standings</a></li>\r\n <li><a\r\n href=\"/contest/384/customtest\">Custom Invocation</a></li>\r\n</ul>\r\n</div>\n\r\n <style>\r\n #facebox .content:has(.diff-popup) {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n }\r\n\r\n .testCaseMarker {\r\n position: absolute;\r\n font-weight: bold;\r\n font-size: 1rem;\r\n }\r\n\r\n .diff-popup {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n display: none;\r\n overflow: auto;\r\n }\r\n\r\n .input-output-copier {\r\n font-size: 1.2rem;\r\n float: right;\r\n color: #888 !important;\r\n cursor: pointer;\r\n border: 1px solid rgb(185, 185, 185);\r\n padding: 3px;\r\n margin: 1px;\r\n line-height: 1.1rem;\r\n text-transform: none;\r\n }\r\n\r\n .input-output-copier:hover {\r\n background-color: #def;\r\n }\r\n\r\n .test-explanation textarea {\r\n width: 100%;\r\n height: 1.5em;\r\n }\r\n\r\n .pending-submission-message {\r\n color: darkorange !important;\r\n }\r\n </style>\r\n <script>\r\n const OPENING_SPACE = String.fromCharCode(1001);\r\n const CLOSING_SPACE = String.fromCharCode(1002);\r\n\r\n const nodeToText = function (node, pre) {\r\n let result = [];\r\n\r\n if (node.tagName === \"SCRIPT\" || node.tagName === \"math\"\r\n || (node.classList && node.classList.contains(\"input-output-copier\")))\r\n return [];\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(OPENING_SPACE);\r\n }\r\n\r\n if (node.nodeType === Node.TEXT_NODE) {\r\n let s = node.textContent;\r\n if (!pre) {\r\n s = s.replace(/\\s+/g, \" \");\r\n }\r\n if (s.length > 0) {\r\n result.push(s);\r\n }\r\n }\r\n\r\n if (pre && node.tagName === \"BR\") {\r\n result.push(\"\\n\");\r\n }\r\n\r\n node.childNodes.forEach(function (child) {\r\n result.push(nodeToText(child, node.tagName === \"PRE\").join(\"\"));\r\n });\r\n\r\n if (node.tagName === \"DIV\"\r\n || node.tagName === \"P\"\r\n || node.tagName === \"PRE\"\r\n || node.tagName === \"UL\"\r\n || node.tagName === \"LI\"\r\n ) {\r\n result.push(\"\\n\");\r\n }\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(CLOSING_SPACE);\r\n }\r\n\r\n return result;\r\n }\r\n\r\n const isSpecial = function (c) {\r\n return c === ',' || c === '.' || c === ';' || c === ')' || c === ' ';\r\n }\r\n\r\n const convertStatementToText = function(statmentNode) {\r\n const text = nodeToText(statmentNode, false).join(\"\").replace(/ +/g, \" \").replace(/\\n\\n+/g, \"\\n\\n\");\r\n let result = [];\r\n for (let i = 0; i < text.length; i++) {\r\n const c = text.charAt(i);\r\n if (c === OPENING_SPACE) {\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"D\" data-uuid=\"ps_0f90334c94689efd384118db23666b79f46751c6\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">D. Volcanoes</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Iahub got lost in a very big desert. The desert can be represented as a <span class=\"tex-span\"><i>n</i> × <i>n</i></span> square matrix, where each cell is a zone of the desert. The cell <span class=\"tex-span\">(<i>i</i>, <i>j</i>)</span> represents the cell at row <span class=\"tex-span\"><i>i</i></span> and column <span class=\"tex-span\"><i>j</i></span> <span class=\"tex-span\">(1 ≤ <i>i</i>, <i>j</i> ≤ <i>n</i>)</span>. Iahub can go from one cell <span class=\"tex-span\">(<i>i</i>, <i>j</i>)</span> only down or right, that is to cells <span class=\"tex-span\">(<i>i</i> + 1, <i>j</i>)</span> or <span class=\"tex-span\">(<i>i</i>, <i>j</i> + 1)</span>. </p><p>Also, there are <span class=\"tex-span\"><i>m</i></span> cells that are occupied by volcanoes, which Iahub cannot enter. </p><p>Iahub is initially at cell <span class=\"tex-span\">(1, 1)</span> and he needs to travel to cell <span class=\"tex-span\">(<i>n</i>, <i>n</i>)</span>. Knowing that Iahub needs <span class=\"tex-span\">1</span> second to travel from one cell to another, find the minimum time in which he can arrive in cell <span class=\"tex-span\">(<i>n</i>, <i>n</i>)</span>.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains two integers <span class=\"tex-span\"><i>n</i></span> <span class=\"tex-span\">(1 ≤ <i>n</i> ≤ 10<sup class=\"upper-index\">9</sup>)</span> and <span class=\"tex-span\"><i>m</i></span> <span class=\"tex-span\">(1 ≤ <i>m</i> ≤ 10<sup class=\"upper-index\">5</sup>)</span>. Each of the next <span class=\"tex-span\"><i>m</i></span> lines contains a pair of integers, <span class=\"tex-span\"><i>x</i></span> and <span class=\"tex-span\"><i>y</i></span> <span class=\"tex-span\">(1 ≤ <i>x</i>, <i>y</i> ≤ <i>n</i>)</span>, representing the coordinates of the volcanoes.</p><p>Consider matrix rows are numbered from 1 to <span class=\"tex-span\"><i>n</i></span> from top to bottom, and matrix columns are numbered from 1 to <span class=\"tex-span\"><i>n</i></span> from left to right. There is no volcano in cell <span class=\"tex-span\">(1, 1)</span>. No two volcanoes occupy the same location. </p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print one integer, the minimum time in which Iahub can arrive at cell <span class=\"tex-span\">(<i>n</i>, <i>n</i>)</span>. If no solution exists (there is no path to the final cell), print -1.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>4 2<br />1 3<br />1 4<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>6<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>7 8<br />1 6<br />2 6<br />3 5<br />3 6<br />4 3<br />5 1<br />5 2<br />5 3<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>12<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>2 2<br />1 2<br />2 1<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>-1<br /></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>Consider the first sample. A possible road is: <span class=\"tex-span\">(1, 1)</span> <span class=\"tex-span\"> → </span> <span class=\"tex-span\">(1, 2)</span> <span class=\"tex-span\"> → </span> <span class=\"tex-span\">(2, 2)</span> <span class=\"tex-span\"> → </span> <span class=\"tex-span\">(2, 3)</span> <span class=\"tex-span\"> → </span> <span class=\"tex-span\">(3, 3)</span> <span class=\"tex-span\"> → </span> <span class=\"tex-span\">(3, 4)</span> <span class=\"tex-span\"> → </span> <span class=\"tex-span\">(4, 4)</span>.</p></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=D]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== statementText) {\r\n $problem.find(\".diff-notifier\").show();\r\n\r\n $problem.find(\".diff-notifier-close\").click(function() {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n $problem.find(\".diff-notifier\").hide();\r\n });\r\n\r\n $problem.find(\"a.view-changes\").click(function() {\r\n $.post(\"/data/diff\", {action: \"getDiff\", a: previousStatementText, b: statementText}, function (result) {\r\n if (result[\"success\"] === \"true\") {\r\n Codeforces.facebox(\".diff-popup\", \"//codeforces.org/s/73366\");\r\n $(\"#facebox .diff-popup\").html(result[\"diff\"]);\r\n }\r\n }, \"json\");\r\n });\r\n }\r\n } else {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n }\r\n });\r\n });\r\n </script>\r\n\r\n\r\n<script type=\"text/javascript\">\r\n $(document).ready(function () {\r\n window.changedTests = new Set();\r\n\r\n function endsWith(string, suffix) {\r\n return string.indexOf(suffix, string.length - suffix.length) !== -1;\r\n }\r\n\r\n const inputFileDiv = $(\"div.input-file\");\r\n const inputFile = inputFileDiv.text();\r\n const outputFileDiv = $(\"div.output-file\");\r\n const outputFile = outputFileDiv.text();\r\n\r\n\r\n if (!endsWith(inputFile, \"standard input\")\r\n && !endsWith(inputFile, \"standard input\")) {\r\n inputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n if (!endsWith(outputFile, \"standard output\")\r\n && !endsWith(outputFile, \"standard output\")) {\r\n outputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n const titleDiv = $(\"div.header div.title\");\r\n\r\n\r\n\r\n String.prototype.replaceAll = function (search, replace) {\r\n return this.split(search).join(replace);\r\n };\r\n\r\n $(\".sample-test .title\").each(function () {\r\n const preId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n const cpyId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n\r\n $(this).parent().find(\"pre\").attr(\"id\", preId);\r\n const $copy = $(\"<div title='Copy' data-clipboard-target='#\" + preId + \"' id='\" + cpyId + \"' class='input-output-copier'>Copy</div>\");\r\n $(this).append($copy);\r\n\r\n const clipboard = new Clipboard('#' + cpyId, {\r\n text: function (trigger) {\r\n const pre = document.querySelector('#' + preId);\r\n const lines = pre.querySelectorAll(\".test-example-line\");\r\n return Codeforces.filterClipboardText(pre.innerText, lines.length);\r\n }\r\n });\r\n\r\n const isInput = $(this).parent().hasClass(\"input\");\r\n\r\n clipboard.on('success', function (e) {\r\n if (isInput) {\r\n Codeforces.showMessage(\"The example input has been copied into the clipboard\");\r\n } else {\r\n Codeforces.showMessage(\"The example output has been copied into the clipboard\");\r\n }\r\n e.clearSelection();\r\n });\r\n });\r\n\r\n $(\".test-form-item input\").change(function () {\r\n addPendingSubmissionMessage($($(this).closest(\"form\")), \"You changed the answer, do not forget to submit it if you want to save the changes\");\r\n const index = $(this).closest(\".problemindexholder\").attr(\"problemindex\");\r\n let test = \"\";\r\n $(this).closest(\"form input\").each(function () {\r\n const test_ = $(this).attr(\"name\");\r\n if (test_ && test_.substring(0, 4) === \"test\") {\r\n test = test_;\r\n }\r\n });\r\n if (index.length > 0 && test.length > 0) {\r\n const indexTest = index + \"::\" + test;\r\n window.changedTests.add(indexTest);\r\n }\r\n });\r\n\r\n $(window).on('beforeunload', function () {\r\n if (window.changedTests.size > 0) {\r\n return 'Dialog text here';\r\n }\r\n });\r\n\r\n autosize($('.test-explanation textarea'));\r\n\r\n $(\".test-example-line\").hover(function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n let top = 1E20;\r\n let left = 1E20;\r\n let problem = $(this).closest(\".problemindexholder\");\r\n $(this).closest(\".input\").find(\".\" + clazz).css(\"background-color\", \"#FFFDE7\").each(function() {\r\n top = Math.min(top, $(this).offset().top);\r\n left = Math.min(left, $(this).offset().left);\r\n });\r\n let testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n if (testCaseMarker.length === 0) {\r\n const html = \"<div class=\\\"testCaseMarker testCaseMarker_\" + end + \" notice\\\"></div>\";\r\n problem.append($(html));\r\n testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n }\r\n if (testCaseMarker) {\r\n testCaseMarker.show()\r\n .offset({top, left: left - 20})\r\n .text(end);\r\n }\r\n }\r\n }\r\n });\r\n }, function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n $(\".\" + clazz).css(\"background-color\", \"\");\r\n $(this).closest(\".problemindexholder\").find(\".testCaseMarker_\" + end).hide();\r\n }\r\n }\r\n });\r\n });\r\n\r\n });\r\n</script>\r\n\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 05:38:07</span> (j3).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/73366/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/73366/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/73366/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/73366/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-73366.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'8122c423be285aae',t:'MTY5NjY0NjI4OC4wMjEwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"},"long_tags":{"kind":"string","value":"[\"Implementation problems, programming technics, simulation\"]"},"short_tags":{"kind":"string","value":"[\"implementation\", \"*2500\"]"},"tutorial_link":{"kind":"string","value":"https://codeforces.com/blog/entry/10476"},"tutorial_page":{"kind":"string","value":"\r\n\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"4f4c31ed5807bbee2a02378cf0944c06\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"h1\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Codeforces Round #225 — Editorial - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n \n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Codeforces Round #225 — Editorial - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/81027/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/81027/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/81027/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/81027/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/81027/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/81027/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/81027/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/81027/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/81027/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/81027/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/81027/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/81027/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/81027/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/81027/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/573cedc6b04c15481941f418269f4057/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='4f4c31ed5807bbee2a02378cf0944c06'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/81027/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fblog%2Fentry%2F10476\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='4f4c31ed5807bbee2a02378cf0944c06'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Pay attention\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n <div style=\"text-align:center;border-bottom: 1px solid rgb(185, 185, 185);margin:0 -0.5em 0.5em -0.5em;padding: 0 1em 0.5em 1em;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 1, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:51:58</span><br/><a href=\"/contestRegistration/1876\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n <div style=\"text-align:center;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 2, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:51:58</span><br/><a href=\"/contestRegistration/1877\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n\r\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div>\r\n\r\n\n <div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\n\r\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='4f4c31ed5807bbee2a02378cf0944c06'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n </label>\r\n </div>\r\n <div style=\"padding: 0 1em 1em 1em;text-align:right;\">\r\n <input style=\"height:1.65em;padding:0 0.75em;\" type=\"submit\" value=\"Find\"/>\r\n </div>\r\n </form>\r\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".handleBox\").autocomplete(\"/data/handles\", {\r\n delay: 200,\r\n width: 200,\r\n selectFirst: false,\r\n matchContains: true,\r\n minChars: 3\r\n });\r\n $(\".handleForm\").attr(\"autocomplete\", \"off\").submit(function () {\r\n var link = \"/profile/userHandle\".replace(\r\n \"userHandle\", $(this).find(\".handleBox\").val()\r\n );\r\n window.location = link;\r\n return false;\r\n });\r\n });\n </script>\n\r\n\r\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Recent actions\n <div class=\"top-links\">\n </div>\n </div>\n <div class=\"recent-actions\">\r\n <ul>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/121073\">Meta Hacker Cup 2023 Round 1</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/.Danet\" title=\"Expert .Danet\" class=\"rated-user user-blue\">.Danet</a> →\r\n <a href=\"/blog/entry/121172\">[TLE on pretest1]</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\" class=\"rated-user user-red\">Pyqe</a> →\r\n <a href=\"/blog/entry/121025\">Codeforces Round #902 (Div. 1, Div. 2, based on COMPFEST 15 — Final Round)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pranshu_Pandya\" title=\"Specialist Pranshu_Pandya\" class=\"rated-user user-cyan\">Pranshu_Pandya</a> →\r\n <a href=\"/blog/entry/121171\">An Interesting Tree Problem</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/sszcdjr\" title=\"Master sszcdjr\" class=\"rated-user user-orange\">sszcdjr</a> →\r\n <a href=\"/blog/entry/119859\">Codeforces Round 896 (Div. 1, Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/119880\">It's Happening! Meta Hacker Cup 2023 Schedule</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/DaviddeGea1\" title=\"Expert DaviddeGea1\" class=\"rated-user user-blue\">DaviddeGea1</a> →\r\n <a href=\"/blog/entry/70917\">Number of ways of dividing an array into 2 parts such that sum of each part is > k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bekh\" title=\"Master Bekh\" class=\"rated-user user-orange\">Bekh</a> →\r\n <a href=\"/blog/entry/74245\">Questions and doubts regarding Aliens DP trick</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a> →\r\n <a href=\"/blog/entry/8192\">Codeforces Round #190 — Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/hocky\" title=\"Candidate Master hocky\" class=\"rated-user user-violet\">hocky</a> →\r\n <a href=\"/blog/entry/95323\">FBHC wuining uw Day? Incwease uw stacc size! (ㅅ´ ˘ `)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/liouzhou_101\" title=\"International Master liouzhou_101\" class=\"rated-user user-orange\">liouzhou_101</a> →\r\n <a href=\"/blog/entry/87598\">Editorial of Codeforces Round #700</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/yeon_gist\" title=\"Newbie yeon_gist\" class=\"rated-user user-gray\">yeon_gist</a> →\r\n <a href=\"/blog/entry/121170\">plusMinusPermutation computing error</a>\r\n <img alt=\"Text created or updated\" title=\"Text created or updated\" src=\"//codeforces.org/s/81027/images/icons/x-update-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/altforminuscontribution\" title=\"Newbie altforminuscontribution\" class=\"rated-user user-gray\">altforminuscontribution</a> →\r\n <a href=\"/blog/entry/121162\">My screen get unexpectedly big, what should I do</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/atcoder_official\" title=\"Unrated, atcoder_official\" class=\"rated-user user-black\">atcoder_official</a> →\r\n <a href=\"/blog/entry/121120\">We will hold UNIQUE VISION Programming Contest 2023 Autumn(AtCoder Beginner Contest 323)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/YouStill_DontKnowMeYet\" title=\"Candidate Master YouStill_DontKnowMeYet\" class=\"rated-user user-violet\">YouStill_DontKnowMeYet</a> →\r\n <a href=\"/blog/entry/117659\">[GYM] Al-Baath Collegiate Programming Contest 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/ankancool\" title=\"Expert ankancool\" class=\"rated-user user-blue\">ankancool</a> →\r\n <a href=\"/blog/entry/121136\">Invitation to AstroByte 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/GeZhiyuan\" title=\"Grandmaster GeZhiyuan\" class=\"rated-user user-red\">GeZhiyuan</a> →\r\n <a href=\"/blog/entry/120943\">Codeforces Round 901 (Div. 1, Div. 2) Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a> →\r\n <a href=\"/blog/entry/120772\">PSA: Increase your stack size before the Meta Hacker Cup, here's how</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/dino_merlin\" title=\"Expert dino_merlin\" class=\"rated-user user-blue\">dino_merlin</a> →\r\n <a href=\"/blog/entry/121145\">Intuitive approach for CEOI Kangaroo?</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/icecuber\" title=\"Grandmaster icecuber\" class=\"rated-user user-red\">icecuber</a> →\r\n <a href=\"/blog/entry/70018\">CSES DP section editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bn00b\" title=\"Newbie Bn00b\" class=\"rated-user user-gray\">Bn00b</a> →\r\n <a href=\"/blog/entry/98820\">[FEATURE REQUEST : ATCODER] TOPICS TAGS AND SORTING BY SOLVE COUNT</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a> →\r\n <a href=\"/blog/entry/121163\">AtCoder Regular Contest 166 Announcement</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/windva\" title=\"Grandmaster windva\" class=\"rated-user user-red\">windva</a> →\r\n <a href=\"/blog/entry/120644\">Codeforces Round 899 (Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Misa-Misa\" title=\"Expert Misa-Misa\" class=\"rated-user user-blue\">Misa-Misa</a> →\r\n <a href=\"/blog/entry/121157\">Someone please help me understand this.</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/shivam565\" title=\"Specialist shivam565\" class=\"rated-user user-cyan\">shivam565</a> →\r\n <a href=\"/blog/entry/108348\">Total number of subarrays with sum atmost k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n </ul>\r\n </div>\r\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/recent-actions\">Detailed →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n</div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li><a\r\n href=\"/profile/fchirica\">fchirica</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/fchirica\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/fchirica\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/fchirica\">Submissions</a></li>\r\n <li><a\r\n href=\"/groups/with/fchirica\">Groups</a></li>\r\n <li><a\r\n href=\"/contests/with/fchirica\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/fchirica\">Problemsetting</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/fchirica\" style=\"text-decoration:none;color:black !important;\">fchirica's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"10531\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/10476\"> <p>Codeforces Round #225 — Editorial</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/fchirica\" title=\"Candidate Master fchirica\" class=\"rated-user user-violet\">fchirica</a>,\r\n <span class=\"format-humantime\" title=\"Jan/20/2014 22:18\">10 years ago</span>,\r\n \r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><h1><a href=\"/contest/384/problem/A\" title=\"Codeforces Round 225 (Div. 2)\">384A - Coder</a></h1><p>Usually, when you don’t have any idea how to approach a problem, a good try is to take some small examples.</p><p>So let’s see how it looks for N = 1, 2, 3, 4 and 5. With C I noted the coder and with * I noted an empty cell.</p><p><img alt=\" \" src=\"/predownloaded/8f/89/8f899efd227362957f283123a7927c7c8a300667.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>By now you should note that answer is N ^ 2 / 2 when N is even and (N ^ 2 + 1) / 2 when N is odd. Good. Generally, after you find a possible solution by taking examples, you need to prove it, then you can code it.</p><p>In order to proof it, one needs to do following steps:</p><p>1/ prove you can always build a solution having N ^ 2 / 2 (or (N ^ 2 + 1) / 2) pieces.</p><p>2/ prove that N ^ 2 / 2 (or (N ^ 2 + 1) / 2) is maximal number – no other bigger solution can be obtained.</p><p>For proof 1/ imagine you do coloring like in a chess table.</p><p><img alt=\" \" src=\"/predownloaded/50/12/50120d92bd0cea3d6a434d09ab4754ea20342351.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>The key observation is that by placing all coders on black squares of table, no two coders will attack. Why? Because a piece placed at a black square can attack only a piece placed at a white square. Again, why? Suppose chess table is 1-based. Then, a square (i, j) is black if and only if i + j is even. A piece placed at (i, j) can attack (i + 1, j), (i – 1, j) (i, j + 1) or (i, j – 1). The sum of those cells is i + j + 1 or i + j – 1. But since i + j is even, i + j + 1 and i + j – 1 are odd, hence white cells.</p><p>Depending on parity of N, number of black cells is either N ^ 2 / 2 or (N ^ 2 + 1) / 2. For N even, one can observe that there are equal amount of black and white cells. Total number of cells is N ^ 2, so number of black cells is N ^ 2 / 2. For N odd, number of black cells is number of white cells + 1. We can imaginary add a white cell to the board. Now, number of black cells will be also equal to number of white cells, so answer is (N ^ 2 + 1) / 2.</p><p>2/ Two coders attack each other if they are placed at two adjacent cells, one black and other one white. One needs to prove that adding more than number from 1/ will cause this to happen. If you place a coder at a white cell, you won’t be able to place at least one coder at a black cell, so in best case you don’t win anything by doing this. Hence, it’s optimally to place all coders on same color cells. Since cells colored in black are always more or equal to white ones, it’s always optimally to choose black color. But number from 1/ is the number of cells having black color. Adding one more piece will force you to add it to a white color cell. Now, you’ll have a piece placed at a black colored cell and one placed at an adjacent white colored cell, so two coders will attack. Hence, we can’t place more than number from 1/ pieces.</p><p>Code: <a href=\"http://pastie.org/8651801\">http://pastie.org/8651801</a></p><h1><a href=\"/contest/384/problem/B\" title=\"Codeforces Round 225 (Div. 2)\">384B - Multitasking</a></h1><p>Let’s start by saying when array A[] is sorted:</p><p>1/ is sorted in ascending order when i < j and A[i] <= A[j]. It is NOT sorted when i < j and A[i] > A[j].</p><p>2/ is sorted in descending order when i > j and A[i] <= A[j]. It is NOT sorted when i > j and A[i] > A[j].</p><p>Iahub can choose 2 indices i, j and swap values when A[i] > A[j]. If A[i] <= A[j], he’ll ignore operation. Hence, if he wants to sort all arrays in ascending order, he chooses indices i, j when i < j and perform operation. Otherwise, in all his operations he uses indices i, j such as i > j. A “good” operation is when choosing indices i < j for ascending order sorting and i > j for descending order sorting. By doing only good operations, after an array is sorted, it will stay sorted forever (for a sorted array, all good operations will be ignored).</p><p>From here we get our first idea: use any sorting algorithm you know and sort each array individually. When print swaps done by sorting algorithm chosen, print them as good operations. However, sorting each array individually can cause exceeding M * (M — 1) / 2 operations limit. Another possible solution would be, after you did an operation to an array, to update the operation to all arrays (you printed it, so it counts to M * (M — 1) / 2 operations limit; making it to all arrays will help sometimes and in worst case it won’t change anything). However, you need to code it very careful in order to make this algorithm pass the time limit. Doing this in a contest is not the best idea, especially when implementation could be complicated and you have no guarantee it will pass time limit.</p><p>So what else can we do? We can think out of box. Instead of sorting specific N arrays, you can sort all possible arrays of length M. Find a sequence of good operations such as, anyhow I’d choose an array of size M, it will get sorted ascending / descending.</p><p>I’ll show firstly how to do for ascending sorting. At position 1 it needs to be minimal element. Can we bring minimal element there using good operations? Yes. Just do “1 2” “1 3” “1 4” ... “1 M”. It basically compares element from position 1 to any other element from array. When other element has smaller value, swap is done. After comparing with all M elements, minimal value will be at position 1. By now on I’ll ignore position 1 and move to position 2. Suppose array starts from position 2. It also needs minimal value from array, except value from position 1 (which is no longer in array). Hence doing “2 3” “2 4” “2 5” ... “2 M” is enough, by similar reasons. For a position i, I need minimal value from array, except positions 1, 2, ..., i – 1. I simply do “i i+1” “i i+2” ... “i M-1” “i M”. By arriving at position i, array will be sorted ascending. The algorithm is simply:</p><p>for (int i = 1; i < M; ++i)</p><p>for (int j = i + 1; j <= M; ++j)</p><p>cout << i << “ “ << j << “\\n”;</p><p>This algorithm does exactly M * (M — 1) / 2 moves.</p><p>Can you find out how to sort array in descending order? Try to think yourself, then if you don’t get it read next. At first position of a descending array it needs to be maximal value. Similarly to ascending order, we can do “2 1” “3 1” “4 1” ... “M 1”. When I’m at a position i and I compare its value to value from position 1, doing operation “i 1” checks if A[i] > A[1]. If so, it swaps A[i] and A[1], so position 1 will contain now the maximum value so far. Similarly to logic from ascending order, when I’m at position i, I need maximum value from array except positions 1, 2, ..., i – 1, so I do “i+1 i” “i+2 i” ... “M i”. Algorithm is:</p><p>for (int i = 1; i < M; ++i)</p><p>for (int j = i + 1; j <= M; ++j)</p><p>cout << j << “ “ << i << “\\n”;</p><p>Obviously, this does as well M * (M — 1) / 2 operations worst case. All algorithm is about 10 lines of code, much better than other solution, which requires two manually sorts and also has a chance to exceed TL.</p><p>Code: <a href=\"http://pastie.org/8651809\">http://pastie.org/8651809</a></p><h1><a href=\"/contest/384/problem/C\" title=\"Codeforces Round 225 (Div. 2)\">384C - Milking cows</a></h1><p>A good strategy to approach this problem is to think how optimal ordering should look like. For this, let’s calculate for each 2 different cows i and j if cow i needs to be milked before or after cow j. As we’ll show, having this information will be enough to build optimal ordering. It is enough to consider only cases when i < j, case when i > j is exactly the opposite of case i < j. For formality, I’ll call the optimal ordering permutation and lost milk the cost of permutation.</p><p>So, for an optimal permutation P let’s take 2 numbers i < j and see in which cases i should appear before j in permutation (i is before j if P[pos1] = i, P[pos2] = j and pos1 < pos2; otherwise we’ll call i is after j). We have 4 possible cases:</p><p>1/ A[i] = 0 and A[j] = 0</p><p>If we put i before j, no additional cost will be added. Since j is in right of i and i only adds cost when it finds elements in left of i, j won’t be affected when processing i. When processing j, i will be already deleted so it won’t affect the cost either. Hence, we can put i before j and no cost will be added.</p><p>2/ A[i] = 0 and A[j] = 1</p><p>Here, i and j can appear in arbitrary order in permutation (i can be before or after j). No matter how we choose them, they won’t affect each other and cost will remain the same.</p><p>3/ A[i] = 1 and A[j] = 0</p><p>As well, here i and j can appear in arbitrary order. If we choose i first, j will be in right of it, so cost of permutation will increase by one. If we choose j first, i will be in left of it so cost of permutation will increase as well. No matter what we do, in this case cost of permutation increases by 1.</p><p>4/ A[i] = 1 and A[j] = 1</p><p>Here, i needs to be after j. This adds 0 cost. Taking i before j will add 1 cost to permutation (since j is in right of i).</p><p>Those 4 cases show us how a minimal cost permutation should look. In a permutation like this, only case 3/ contributes to final cost, so we need to count number of indices i, j such as i < j and A[i] = 1 and A[j] = 0 (*). If we show a permutation following all rules exists, task reduces to (*).</p><p>By cases 2/ and 3/ it follows that in an optimal permutation, it only matters order of elements having same value in A[]. We can put firstly all elements having value 0 in A[], then all elements having value 1 in A[]. We can order elements having value 0 by case 1/ and elements having value 1 by case 4/. More exactly, suppose i1 < i2 < ... < im and (A[i1] = A[i2] = ... = A[im] = 0) and j1 > j2 > ... > jn (A[j1] = A[j2] = ... = A[jn] = 1). Then, a permutation following all rules is {i1, i2, ..., im, j1, j2, ..., jn}. This permutation can always be built.</p><p>Hence, task reduces to (*): count number of indices i, j such as i < j and A[i] = 1 and A[j] = 0. We can achieve easily an O(N) algorithm to do this. Let’s build an array cnt[j] = number of 0s in range {j, j + 1, ..., N} from array A. We can easily implement it by going backwards from N to 1. The result is sum of cnt[i], when A[i] = 1.</p><p>Code: <a href=\"http://pastie.org/8651813\">http://pastie.org/8651813</a></p><h1><a href=\"/contest/384/problem/D\" title=\"Codeforces Round 225 (Div. 2)\">384D - Volcanoes</a></h1><p>Our first observation is that if there is a path from (1, 1) to (N, N), then the length of path is 2 * N – 2. Since all paths have length 2 * N – 2, it follows that if there is at least one path, the answer is 2 * N – 2 and if there isn’t, the answer is -1. How to prove it? Every path from (1, 1) to (N, N) has exactly N – 1 down directions and exactly N – 1 right directions. So, total length for each path is N – 1 + N – 1 = 2 * N – 2. </p><p>So we reduced our problem to determine if there is at least one path from (1, 1) to (N, N). This is the challenging part of this task, considering that N <= 10 ^ 9. How would you do it for a decently small N, let’s say N <= 10^3 . One possible approach would be, for each row, keep a set of reachable columns. We could easily solve this one by doing this: if (i, j) denotes element from ith row and jth column, then (i, j) is (is not) reachable if:</p><p>if (i, j) contains a volcano, then (i, j) is not reachable. Otherwise, if at least one of (i – 1, j) and (i, j – 1) is reachable, then (i, j) is reachable. Otherwise, (i, j) is not reachable.</p><p>What’s the main problem of this approach? It needs to keep track of 10^9 lines and in worst case, each of those lines can have 10^9 reachable elements. So, worst case we need 10^9 * 10^9 = 10^18 operations and memory.</p><p>Can we optimize it? We can note for beginning that we don’t need to keep track of 10^9 lines, only m lines are really necessarily. We need only lines containing at least one obstacle (in worst case when each line contains only one obstacle, we need m lines). How to solve it this way? Suppose line number x contains some obstacles and lines x + 1, x + 2, x + 3 do not contain any obstacle. Suppose we calculated set S = {y | cell (x, y) is reachable}. How would look S1, S2, S3 corresponding to lines x + 1, x + 2, x + 3? For S1, we can reach cell (x + 1, ymin), where ymin is minimal value from set S. Then, we can also reach {ymin + 1, ymin + 2, ..., N}, by moving right from (x + 1, ymin). So S1 = {ymin, ymin + 1, ..., N}. How do S2 and S3 look? It’s easy to see that they’ll be as well {ymin, ymin + 1, ..., N}. So we get following optimization: suppose set of lines containing at least one obstacle is {L1, L2, ..., Lk}. We need to run algorithm only for lines L1, L1 + 1, L2, L2 + 1, L3, L3 + 1, ..., Lk, Lk + 1.</p><p>It looks like we didn’t make anything with this optimization. Even if we calculate for m lines, each line can still have 10^9 reachable positions. So worst case we perform 10^14 operations. We need something better for managing information from a line. You can note that for a given line y, there are a lot of positions having consecutive values. There are a lot of positions (x, y) and (x, y + 1) both reachable. This should give us following idea: what if instead of keeping reachable positions, we keep reachable ranges? That is, for each line x we keep a set of ranges S = {(a, b) | all cells (x, k) with a <= k <= b are reachable}. </p><p>How many ranges can it be for a line? If the line contains m obstacles, there are m + 1 ranges. Suppose for line x all cells are reachable, but for line x + 1 cells (x + 1, 3) (x + 1, 5) (x + 1, N – 1) are blocked. Then, the ranges of reachable cells are [1, 2] [4, 4], [6, N – 2] and [N, N]. By now, we get worst case m lines and worst case each line having m elements, so in worst case we’d have to handle m * m = 10 ^ 10 events. This may still look too much, but happily this bound is over estimated. If a line has o obstacles, there can be at most o + 1 ranges. If lines L1, L2, ..., Lk have {o1, o2, ..., ok} obstacles, there’ll be at most o1 + o2 + ... + ok + k ranges. But o1 + o2 + ... + ok = m and also k is at most m (proved above why we’re interested in at most m lines), so in worst case we get m + m = 2 * m ranges. Yaay, finally a decent number of states for this problem :)</p><p>So, we iterate each line we’re interested in. Let’s find set of ranges for this line, thinking that all cells from line above are reachable. This is easy to do. After we get our ranges like all cells from above can be visited, let’s think how having obstacles above can influence current ranges. After adding ranges from above, current ranges can’t increase (obviously), they can only decrease, remain the same or some of them can become empty. So, let’s take each range [a, b] from current line and see how it will transform after adding ranges from previous line. </p><p>Given range [a, b], it can transform only in [a’ , b] with a’ >= a. If a’ > b, then obviously range is empty. Why second number of range keeps constant? Let a’ smallest reachable column from current line which is in range [a, b]. It’s enough to check a’ >= a, as if a’ > b, range will be empty. It’s obviously why we need to keep a’ smallest value possible >= a: we’re interested to keep range as big as possible and as less as we cut from left, as big it is. Once we’ve found a’ in range [a, b] (or a’ > b if range is empty) all cells {a’ + 1, a’ + 2, ..., b} are reachable as well by going right from a’, so if interval is not empty, then second number defining it remains b.</p><p>Next question is how to find a’ fast enough. In order a point a’ to be reachable on current range, it also needs to exist a range on previous line containing it. If the range from previous line is [pa, pb] then a’ needs to follow 3 conditions:</p><p>a’ minimal such as</p><p>pa <= a’ <= pb</p><p>a’ >= a</p><p>What if instead of finding a’ we find [pa, pb]? Then a’ is max(pa, a). In order a’ to be as small as possible, since a is constant, pa needs to be as small as possible. So we reduced it to:</p><p>pa minimal pb >= a’ >= a <=> pb >= a</p><p>Intervals from previous line are disjoint, no 2 intervals cross each other. It means that if pb is minimal, than pa is minimal too (if we increase pb, then pa will increase too, so it won’t be minimal). Hence, you need to find an interval [pa, pb] such as pb is minimal and pb >= a. Then, a’ is max(a, pa). This is easy to do if we sort all intervals from previous line increasing by second value (pb), then we binary search for value a. </p><p>Finally, after running algorithm for all lines, last range from last line has second number N (assuming ranges are sorted increasing by second value), then there exist a path, otherwise there does not exist. This algorithm should run O(m * logm) worst case, good enough to pass. </p><p>Code: <a href=\"http://pastie.org/8651817\">http://pastie.org/8651817</a></p><h1><a href=\"/contest/384/problem/E\" title=\"Codeforces Round 225 (Div. 2)\">384E - Propagating tree</a></h1><p>This is kind of task that needs to be break into smaller subproblems that you can solve independently, then put them together and get solution.</p><p>Let’s define level of a node the number of edges in the path from root to the node. Root (node 1) is at level 0, sons of root are at level 1, sons of sons of root are at level 2 and so on.</p><p>Now suppose you want to do an operation of type 1 to a node x. What nodes from subtree of x will be added +val (a positive value)? Obviously, x will be first, being located at level L. Sons of x, located at level L + 1 will be added –val. Sons of sons, located at level L + 2, will be added value +val again. So, nodes from subtree of x located at levels L, L + 2, L + 4, ... will be added a +val, and nodes located at levels L + 1, L + 3, L + 5 will be added a –val. Let’s take those values of L modulo 2. All nodes having remainder L modulo 2 will be added a +val, and nodes having reminder (L + 1) modulo 2 will be added –val. In other words, for a fixed x, at a level L, let y a node from subtree of x, at level L2. If L and L2 have same parity, +val will be added to y. Otherwise, -val will be added to y.</p><p>From here we have the idea to split nodes of tree in 2 sets – those being located at even level and those being located at odd level. What still makes the problem hard to solve? The fact that we have a tree. If nodes from a subtree would be a contiguous sequence instead of some nodes from a tree, problem would be simpler: the problem would reduce to add / subtract values to all elements of a subarray and query about a current value of an element of array. So, how can we transform tree to an array, such as for a node x, all nodes from subtree of x to be a subarray of array?</p><p>The answer is yes. We can do this by properties of DFS search. Before reading on, make sure that you know what is discovery time and finish time in a DFS search. Let’s build 3 arrays now – discover[], representing nodes in order of their discover times (a node is as before in discover as it has a small discover time), begin[] = for a node, in which time it was discovered and end[] = what’s last time of a discovered node before this node finishes. For a subtree of x, all nodes in the subtree are nodes in discover from position begin[x] to end[x].</p><p>Example: suppose you have tree 1-5; 1-6; 6-7; 6-4; 4-2; 4-3</p><p>Discover is {1, 5, 6, 7, 4, 2, 3}.</p><p>begin is {1, 6, 7, 5, 2, 3, 4}.</p><p>end is {7, 6, 7, 7, 2, 7, 4}.</p><p>What’s subtree of node 6? elements of discover from position begin[6] to end[6]. In this case, from 3 to 7, so elements {6, 7, 4, 2, 3}. You can see it’s correct and take more examples if you want :)</p><p>Now, we reduced problem to: you’re given an array A. you can perform 2 operations:</p><p>1/ increase all elements from a range [x, y] to a value val (val can be negative, to treat subtractions)</p><p>2/ what’s current value of an element from position pos.</p><p>Those who solved “Iahub and Xors” from my last round, CF 198, should probably say they saw something similar before. If you didn’t solve problem before, I encourage you to do it after you solve this one, it uses a similar idea to what will follow now. Also, if you don’t know Fenwick trees, please read them before moving on. An alternative would be for this task using segment trees with lazy update, but I see this one more complicated than needed.</p><p>I’ll use now a not so common approach when dealing with data structures. Instead of keeping in a node the result, like you usually do, I’ll keep just an auxiliary information. So what algorithm proposed does:</p><p>Let A an array, initially with all elements 0.</p><p>When you need to update range [x, y] with value val, you simply do A[x] += val and A[y + 1] -= val.</p><p>When you need to answer a query about position pos, you output A[1] + A[2] + ... + A[pos].</p><p>Implemented brute force, you get O(1) per update and O(N) per query. However, these both are operations supported by a Fenwick tree, so you can get O(logN) per operation.</p><p>It may not be very clear why this algorithm works. Let’s take a closer look: an update needs to add value val only to range [x, y]. When you query a position pos, let’s see if algorithm handles it correctly:</p><p>1/ pos < x. In this case, result must not be affected by my update. Since pos < x and I only updated 2 values with indices >= x, when doing A[1] + A[2] + ... + A[pos] it won’t matter at all I did that update – at least not for this query.</p><p>2/ x <= pos <= y. Here, for a pos, I need to add value val only once. We add it only at A[x] – in this way it will be counted once, and it will be considered for each elements from range [x, y] (since an element at position p from range [x, y] has p >= x, in A[1] + A[2] + ... + A[p] I’ll have to consider A[x]).</p><p>3/ pos > y. Here I don’t have to consider the query. But it would be considered when processing A[x]. But if I add to A[y + 1] value –val I’ll just cancel the value previously added.</p><p>Code (actually we use just one Fenwick tree instead of 2, can you think why it works? :) ) : <a href=\"http://pastie.org/8651824\">http://pastie.org/8651824</a></p><h1><a href=\"/contest/383/problem/D\" title=\"Codeforces Round 225 (Div. 1)\">383D - Antimatter</a></h1><h2>Author's solution</h2><p>The problem is: given an array, iterate all possible subarrays (all possible elements such as their indexes are consecutive). Now, for a fixed subarray we need to know in how many ways we can color its elements in black and white, such as sum of black elements is equal to sum of white elements. The result is sum of this number, for each subarray.</p><p>Let’s solve an easier problem first. This won’t immediately solve the harder version, but it will be useful later. Suppose you’ve fixed a subarray. In how many ways can you color it with black and white? Suppose subarray has N elements and sum of them is M. Also, suppose for a coloring, sum of blacks is sB and sum of whites is sW. For coloring to be valid, sB = sW. But we also know that sB + sW = M (because each element is colored by exactly one color). We get that 2 * sB = M, so sB = M / 2. The problem is now: in how many ways can we color elements in black such as sum of blacks is M / 2 (after we fix a black coloring, we color with white non colored elements; sum of white colored elements is also M / 2). This is a well known problem: Knapsack problem. Let ways[i][j] = in how many ways one can obtain sum j from first i elements. When adding (i + 1) object, after ways[i] is calculated, for a fixed sum j we can do 2 things: add (i + 1) object to sum j or skip it. Depending of what we chosen, we add value ways[i][j] to ways[i + 1][j + value[i + 1]] or to ways[i + 1][j]. The result is in ways[N][M / 2]. This works in O(N * M) time.</p><p>An immediate solution can be obtained now: take all subarrays and apply above approach. This leads to an O(N ^ 2 * M ^ 2) solution, which is too much. One can reduce complexity to O(N ^ 2* M) by noting that processing subarray [i, j] can be done with already calculated values for subarray [i, j – 1]. Hence, instead of adding N elements, it’s enough to add 1 element to already calculated values (element from position j). Sadly, O(N ^ 2 * M) is still too slow, so we need to find something better. The solution presented below will look forced if you didn’t solve some problems with this technique before. It’s hard to come with an approach without practicing this kind of tasks. But don’t worry, as much as you practice them, as easily you’ll solve those problems.</p><p>We’ll solve task by divide and conquer. Complexity of this solution is O(N * M * logN). Let f(left, right) a function that counts number of colorings for each subarray [i, j], such as subarray [i, j] is included in subarray [left, right] (left <= i <= j <= right). Answer is in f(1, N). The trick is to define a value med = (left + right) / 2 (very frequent trick in divide and conquer problems, called usually a median). We can next classify [i, j] subarrays in 3 types:</p><p>1/ i <= med j <= med</p><p>2/ i > med j > med</p><p>3/ i <= med j > med</p><p>We can solve 1/ and 2/ by calling f(left, med) and f(med + 1, right). The remained problem is when i <= med and j > med. If we solve 3/ in O((right – left) * M) time, this will be enough to overall achieve O(N * M * logN) (for this moment trust me, you’ll see later why it’s so :) ).</p><p>Let’s denote by i1 last i1 elements from subarray [left, med]. Also, let’s note by i2 first i2 elements from subarray [med + 1, right]. For example, let left = 1 and right = 5, with array {1, 2, 3, 4, 5}. med is 3 and for i1 = 2 and i2 = 1, “left” subarray is {2, 3} and “right” subarray is {4}. By iterating i1 from 1 to med – left + 1 and i2 from 1 to right – med and then unite subarrays i1 and i2, we obtain all subarrays described in 3/ . Let’s denote by j1 sum of a possible black coloring of i1. Similarly, j2 is sum of a possible black coloring of i2.</p><p>Suppose we fixed i1, i2, j1 and j2. When it’s the coloring valid? Let S sum of united subarrays i1 and i2 (S = value[med – i1 + 1] + value[med – i1 + 2] + ... + value[med] + value[med + 1] + ... + value[med + i2 – 1] + value[med + i2]). Now it’s time to use what I explained at the beginning of solution. The coloring is good only when j1 + j2 = S / 2. We can rewrite the relation as 2 * (j1 + j2) = sum_of_elements_from_i1 + sum_of_elements_from_i2. We can rewrite it even more:</p><p>2 * j1 + 2 * j2 — sum_of_elements_from_i1 — sum_of_elements_from_i2 = 0</p><p>2 * j1 – sum_of_elements_from_i1 = sum_of_elements_from_i2 – 2 * j2 = combination_value</p><p>This relation is the key of solving problem. You can see now that relation is independent in “left” and “right” side. We calculate left[i1][j1] and right[i2][j2] = in how many ways can I obtain sum of blacks j1 (j2) from first i1 (i2) from left (right) side. Let’s calculate also count[value] = in how many ways can I obtain combination_value equal to value in the right side. For some fixed (i2, j2) I add to count[sum_of_elements_from_i2 – 2 * j2] value right[i2][j2]. In this way count[] is calculated correctly and completely. Now, let’s fix a sum (i1, j1) in the left side. We’re interested how many good colorings are such as there exist a coloring of j1 in i1 elements (the endpoint of “left” is fixed to be i1 and I need to calculate endpoints i2 for right, then to make colorings of i2). A coloring is good if combination_value of (i1, j1) and (i2, j2) is equal. Hence, I need to know in how many ways I can color i1 elements to obtain sum j1 and also I need to know in how many ways I can color elements from right to obtain same combination_value as it’s in the left. It’s not hard to see that answer for a fixed (i1, j1) is left[i1][j1] * count[2 * j1 – sum_of_elements_from_i1]. This takes O((right – left) * M) time.</p><p>The only thing remained in the problem is to see why complexity is O(N * M * logN). We can assume N is a power of 2 (it not, let’s round N to smallest power of 2 bigger than N; complexity for N is at least as good as complexity for this number). Draw a binary complete tree with N nodes. Each node corresponds to an appeal of f(). For a level, exactly O(N * M) operations are performed. To see why:</p><p>For level 1, there’ll be 1 node performing N * M operations.</p><p>For level 2, there’ll be 2 nodes performing (N / 2) * M operations. Summing up we get O(N * M).</p><p>For level 3, there’ll be 4 nodes performing (N / 4) * M operations. Summing up we get O(N *M) as well.</p><p>and so on.</p><p>So for each level we perform O(N * M) operations. A binary complete tree has maximum O(logN) levels, so overall complexity is O(N * M * logN).</p><p>Code: <a href=\"http://pastie.org/8651826\">http://pastie.org/8651826</a></p><h2>Solution fount by contestants</h2><p>This was totally unexpected to us :) Good job finding it, you guys are really smart. </p><p>We observe that x units of antimatter is the same thing as -x units of matter. Then we can consider that an element produces either x or -x units of matter. A valid substring is one that can have the sum of the elements 0. The problem is reduced to finding how many different substrings can we have with sum 0 (a substring is different than another one if it has different indices, or if at least one element produces matter in one and antimatter in the other).</p><p>This problem can be solved with dynamic programming. We will hold D[i][j] = the number of substrings that end in element i, and have sum j. It's easy to see that D[i + 1][j] = D[i][j — x] + D[i][j + x], where x is the value of the current element (we can put either -x or x). After we finish computing all the values for current i, we add to the solution D[i][0] (how many valid substrings do we have). After that, we add 1 to D[i][0], meaning that there is an empty substring starting at position i (however, we don't need to add it to the answer).</p><p>For a code, check passing submissions during contest. </p><h2><a href=\"/contest/383/problem/E\" title=\"Codeforces Round 225 (Div. 1)\">383E - Vowels</a></h2><h2>Author's solution</h2><p>Let's iterate over all possible vowel sets. For a given set {x1, x2, ..., xk} we're interested in number of correct words from dictionary. After a precalculation, we can do it in O(k).</p><p>Suppose our current vowel set is {x1, x2, ..., xk}. How many words are covered by the current vowels? By definition, we say a word is covered by a set of vowels if at least one of 3 letters of word is in vowel set. We can calculate this number using principle of inclusion and exclusion. We’ll denote by |v1, v2, v3, ...| = number of words containing ALL of vowels v1, v2, v3, ... . Using principle of inclusion and exclusion we get:</p><p>number_of_words_covered = |x1| + |x2| + .. + |xk| — |x1, x2| — |x1, x3| — .... + |x1, x2, x3| + |x1, x2, x4| + .... + |xk-2, xk-1, xk|. This formula is simply a reformulation of principle of inclusion and exclusion. You can easily observe that |v1, v2, ..., vk| makes sense only when k is at most 3, as no word from input can contain 4 or more letters (and hence can’t contain 4 or more vowels). </p><p>Example:</p><p>Suppose words are abc, abd and bcd. </p><p>|a| = 2 (first 2 words both contain character a).</p><p>|a, b| = 2 (as well, first 2 words contain characters a and b).</p><p>|b| = 3 (all 3 words contain character b).</p><p>|a, b, d| = 1 (only second word contains all 3 characters).</p><p>Also, note how principle of inclusion and exclusion works. number of words covered for vowels {a, b} is |a| + |b| — |a, b| = 2 + 3 – 2. Indeed, answer is 3.</p><p>We divide our problem in 3 subproblems. First one, for a vowel set, compute sum of |a|, where a is a letter from subset. Second, compute sum of |a, b|, where both a and b are letters from set. Third, compute sum of |a, b, c|, where a, b, c are letters from set. As stated, the answer is number_from_1st_step + number_from_3rd_step – number_from_2nd_step. If you followed me, you’ll see that we want to compute results for each subproblem in O(queryLetters).</p><p>First subproblem can be solved trivially in O(queryLetters). Let array single[], with following meaning: single[c] is how many words contain character c. It can be trivially precomputed in O(24 * N). Note that if a word contains twice/third times a character c, it needs to be counted only one (e.g. word aba will add only 1 to single[a]). For compute result of this subproblem for a given set of vowels, I’ll take all letters from set. If letter belongs to set, I add to result single[letter]. This step can be also be solved in O(1), but there’s no need, since other subproblems allow only an O(queryLetters) solution. </p><p>For second and third subproblems it’s a little more difficult. I’ll present here how to solve second subproblem and some hints for third one (if you understand second, with hints you should be able to solve third one by your own).</p><p>Similarly to first step, I’ll define a matrix double[c1][c2] = how many words contain both characters c1 and c2. A trivially solution would be, for a given vowel set, take all combinations of letters c1 and c2 that belong to set and add to result value double[c1][c2]. However, this solves each query in O(queryLetters^2), which is too slow.</p><p>Note, if we’d have 12 letters, instead of 24, this approach would be fast enough. From here it comes a pretty classical idea in exponential optimization: meet in the middle attack. We split those 24 letters in 2 groups: first 12 letters and last 12 letters. The answer for a subset is sum of double[c1][c2] (when c1 and c2 belong to current vowel set) when</p><p>1/ c1 and c2 belong to first 12 letters</p><p>2/ c1 and c2 belong to last 12 letters</p><p>3/ c1 belongs to first 12 letters and c2 belongs to last 12 letters</p><p>1/ and 2/ can be immediately precalculated as stated above, in O(2 ^ 12 * 12 ^ 2). We’ll remember results for each half using bitmasks arrays. Let Half1[mask] = sum over double[c1][c2], when c1 and c2 are in first 12 letters and correspond to 1 bits of mask. Half2[mask] is defined similarly, but for last 12 letters (e.g. subset {a, c, d} corresponds to bitmask 2^0 + 2^2 + 2^3 = 13 in first half and subset {m, n, p} corresponds to bitmask 2^0 + 2^1 + 2^3 = 11 for second half). Now, for a given subset, one can answer first 2 parts in O(queryCount) worst case (read input for a query and convert it to bitmasks). </p><p>How to answer 3? With another precalculation, of course. We know c1 letter needs to be in first 12 letters and c2 needs to be in last 12 letters. The precalculation we do here is: mixed_half[mask][i] = sum over |c1, c2|, when c1 belongs to first half and is a 1 bit of mask and c2 is i-th character of second half. Hence, for a query, we can fix character from second half (c2, by iteration of query letters from second half) and know sums of |c1, c2| between it and all available characters from first half after we do this precalculation. Also, precalculation is done trivially in O(2 ^ 12 * 12^2): fix mask, fix i and then iterate over 1 bits from mask and add double[c1][c2]. </p><p>Third subproblem is left, but it can be done similarly to second one. Instead of double[c1][c2], we’ll have triple[c1][c2][c3] = how many words contain all 3 characters c1, c2 and c3? We also do meet in the middle here, divide those 24 letters into 2 sets of 12 letters. We have 4 cases:</p><p>1/ c1, c2, c3 belong to first half</p><p>2/ c1, c2, c3 belong to second half</p><p>3/ c1, c2 belong to first half and c3 to second half</p><p>4/ c1 belongs to first half and c2, c3 to second half</p><p>1/ and 2/ are done brute force, like in second subproblem (the only difference is we choose 3 characters instead of 2, having complexity O(2 ^ 12 * 12 ^ 3)). For 3/ and 4/ we also precompute 2 matrixes: </p><p>mixed_two_one[mask][i] = c1 and c2 belong to mask from first half and c3 is i-th character from second half </p><p>and </p><p>mixed_one_two[mask][i] = c1 is i-th character from first half and c2, c3 belong to mask from second half. </p><p>Those can also be calculated in O(2 ^ 12 * 12^3).</p><p>So precalculation part is O(2 ^ 12 * 12 ^ 3) = 7077888 operations.</p><p>For calculate answering queries complexity, take all numbers from 0 to 2^24 — 1 and sum their bit count. This is a well known problem, the sum is 0 * C(24, 0) + 1 * C(24, 1) + ... + 24 * C(24, 24) = 201326592. In total we get 208404480 operations. C++ source makes them in 2 seconds. </p><p>Code: <a href=\"http://pastie.org/8651829\">http://pastie.org/8651829</a></p><h2>Solution fount by contestants</h2><p>Like in D1 D task, official solution was over complicated. This solution is more simple to understand, code and it's more elegant. If someone wants to complicate his life, (s)he can code also official solution :)</p><p>Let's start by assigning a bitmask to each word in following way: ith bit is 1 if and only if letter ('a' + i) appears in the current word. For example, for word acd, its bitmask is 2^0 + 2^2 + 2 ^ 3 = 13 and for word aab its bitmask is 2^0 + 2^1 = 3. After reading the words from dictionary, we store a matrix cnt[mask] = how many words from dictionary correspond to mask?</p><p>We iterate bitmasks from 0 to 2^24 — 1, this time corresponding to each possible question of Iahubina. Let's focus on a bitmask X. We need to get sum of cnt[mask], when mask and X share at least one common bit having value 1 (formally (X AND mask) > 0). In order to do this, we need a reduction which may be not so obvious. </p><p>What if instead of counting all words containing at least one of vowels {w1, w2, ..., wk} we count all words which don't contain ANY of vowels {w1, w2, ..., wk}? Suppose this number is ret. Then, all words containing at least one of vowels is N — ret. From all words, we erase those words which do not contain any vowels from set {w1, w2, ..., wk} (and which obviously are wrong words). Obviously, it's left only words containing at least one vowel, so good words. Now, for a word not to contain any of vowels {w1, w2, ..., wk} it needs to contains ONLY vowels from set {"a", "b", "c", ..., "x"} \\ {w1, w2, ..., wk} (set of allowed letters from which we erased vowels w1, w2, ..., wk}. </p><p>And this is reduction we needed. For a bitmask X we need to calculate sum of cnt[mask], where mask is a subset of X (we can set some bits from X from 1 to 0 in order to obtain mask). For a mask, let's keep this sum in res[mask]. We can calculate res array using divide and conquer.</p><p>Let's make a function solve(left, right), which completes array res in the way described above, if we consider only elements cnt[k] with left <= k < right (for simplicity, I'll consider elements which do not lie in this range to be equal to 0). Now we need to solve for a range [left, right]. Let's have in res1[] = solve(left, med) and in res2[] = solve(med, right), where med = (left + right) / 2. We need to put together res1[] and res2[] in order to obtain res[].</p><p>for (int i = left; i < med; ++i) res[i] = res1[i];</p><p>Numbers in [left, med] have most significant bit equal to 0. We can only keep it 0 and add what we calculated before. We can't add any element from res2[], because those elements have most significant bit equal to 1 and we're not allowed to change bit 0 into bit 1.</p><p>for (int i = med; i < right; ++i) res[i] = res1[i — med] + res2[i];</p><p>Here, most significant bit is 1. Adding res1[] corresponds to changing bit from 1 to 0, adding res2[] corresponds to leaving bit 1.</p><p>Of course, we need to threat the base case here, too. When left + 1 = right, res[left] = cnt[left]. We can keep only one array res[] instead of 3, I explained it this way only for simplicity. Also, there is no need for keeping separate arrays for res[] and cnt[], one can solve all task with only one array. In order to get res[], we simply call solve(0, 2^24).</p><p>Complexity of solution is O(2 ^ 24 * 24). I leave the proof homework, it's almost identical to complexity proof of D1 D "Author solution" (that with building a binary tree).</p><p>For a reference solution, check <a class=\"rated-user user-red\" href=\"/profile/Endagorion\" title=\"Grandmaster Endagorion\">Endagorion</a>'s AC source during contest. </p></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/384\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 225 (Div. 2)</a> </span>\r\n </div>\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/383\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 225 (Div. 1)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-12457-10531\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"12457\",\n blogEntryId: \"10476\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n <div style=\"font-size: 1.1rem;line-height: 11px;\">\r\n <img style=\"vertical-align: middle;\" src=\"//codeforces.org/s/81027/images/blog/tags.png\" title=\"Tags\" alt=\"Tags\"/>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=codeforces\" class=\"tag notice\" style=\"text-decoration: none;\">codeforces</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=225\" class=\"tag notice\" style=\"text-decoration: none;\">225</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=editorial\" class=\"tag notice\" style=\"text-decoration: none;\">editorial</a>\r\n </span>\r\n </div>\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-10531\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+418</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-10531\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/fchirica\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/fchirica\">\n fchirica\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Jan/20/2014 22:18\">10 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/10476#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/10476#comments\">\n 52\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"10547\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (45)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158582\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PAP\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/78534/avatar/d5bcc04085999f83.jpg'/> </a>\n <div><a href=\"/profile/PAP\" title=\"Candidate Master PAP\" class=\"rated-user user-violet\">PAP</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 22:40\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158582\" href=\"?#comment-158582\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158582\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"32\"\r\n data-commentUserId=\"78534\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+32</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158582\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>perfect editorial! thanks a lot!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158582 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158582 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158582\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158591\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/eduardische\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2320/avatar/3ac70493aa90ad2e.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/eduardische\" title=\"International Master eduardische\" class=\"rated-user user-orange\">eduardische</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 22:48\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158591\" href=\"?#comment-158591\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"158591\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"158591\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"10\"\r\n data-commentUserId=\"2320\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+10</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158591\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Just would like to report a typo in 383D contestants' solution: the formula computes D[i+1][j] and not D[i][j]. Thanks for the quick editorial!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158591 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158591 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158591\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158596\" commentParentId=\"158591\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/fchirica\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/57267/avatar/4e655c69b8ad66c2.jpg'/> </a>\n <div><a href=\"/profile/fchirica\" title=\"Candidate Master fchirica\" class=\"rated-user user-violet\">fchirica</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 22:52\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158596\" href=\"?#comment-158596\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-158591\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158596\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"15\"\r\n data-commentUserId=\"57267\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+15</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158596\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks. Fixed. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158596 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158596 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158596\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158598\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Mikester\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/109566/avatar/401b6d72d8f2e768.jpg'/> </a>\n <div><a href=\"/profile/Mikester\" title=\"Master Mikester\" class=\"rated-user user-orange\">Mikester</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 22:54\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158598\" href=\"?#comment-158598\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158598\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"13\"\r\n data-commentUserId=\"109566\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+13</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158598\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>elfus has some of the best rounds on Codeforces, and definitely the best editorials. Congratulations to you and Rares for the round !</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158598 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158598 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158598\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158599\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/iPs\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/144469/avatar/10358ae72910ceac.jpg'/> </a>\n <div><a href=\"/profile/iPs\" title=\"Expert iPs\" class=\"rated-user user-blue\">iPs</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 22:54\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158599\" href=\"?#comment-158599\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158599\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"33\"\r\n data-commentUserId=\"144469\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+33</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158599\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>best editorial I have ever seen in codeforces</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158599 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158599 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158599\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158600\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/bli0042\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/88584/avatar/51c3a9b55a3537fa.jpg'/> </a>\n <div><a href=\"/profile/bli0042\" title=\"Candidate Master bli0042\" class=\"rated-user user-violet\">bli0042</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 22:54\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158600\" href=\"?#comment-158600\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"158600\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"158600\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"88584\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158600\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For Div 2C, if A[i] = A[j] = 0 and we put i before j, won't j lose milk? Or am I misinterpreting the solution?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158600 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158600 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158600\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158601\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/aabs08\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/aabs08\" title=\"Expert aabs08\" class=\"rated-user user-blue\">aabs08</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 22:55\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158601\" href=\"?#comment-158601\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"158601\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"158601\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"9\"\r\n data-commentUserId=\"86699\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+9</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158601\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>One of the best editorials i came across in codeforces :D otherwise the editorial here are really very short and objective.</p><p>Every one here should write editorials like you :) !!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158601 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158601 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158601\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158607\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Xellos\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/69675/avatar/8526bcfc8e687b43.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/Xellos\" title=\"International Grandmaster Xellos\" class=\"rated-user user-red\">Xellos</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 23:03\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158607\" href=\"?#comment-158607\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"158607\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"158607\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"17\"\r\n data-commentUserId=\"69675\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+17</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158607\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Finally a tutorial worth upvoting!</p><p>I didn't really need to think about D. As soon as I saw the constraint on <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/986936bec272878d92f9c6fb0f0ce3c5b118cc0e.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />, I decided to try a DP on (position,sum) — it was a massive hint for me. Well, sometimes it just happens that there's a simple solution, which the author doesn't realize :D. Maybe this could be eliminated by some extensive "problem testing" by random capable people?</p><p>I guess I was also lucky in not trying to solve B. I solved in the order: A (because it's easy), C (because I like it), D (because it's easy) :D</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158607 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158607 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158607\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158610\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Mostafa_36a2\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/137637/avatar/28a01293a2b409.jpg'/> </a>\n <div><a href=\"/profile/Mostafa_36a2\" title=\"Specialist Mostafa_36a2\" class=\"rated-user user-cyan\">Mostafa_36a2</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 23:09\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158610\" href=\"?#comment-158610\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158610\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"-9\"\r\n data-commentUserId=\"137637\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-9</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158610\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I've found a very short solution for Div2 C , by zxz5759209</p> <pre><code>scanf("%d",&n);\n LL cnt=0,sum=0;\n for(int i=1;i<=n;i++)\n {\n scanf("%d",&x);\n cnt+=(LL)x;\n if(!x)sum+=cnt;\n }\n printf("%I64d\\n",sum);\n</code></pre></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158610 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158610 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158610\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158641\" commentParentId=\"158610\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Robert.One\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Robert.One\" title=\"Pupil Robert.One\" class=\"rated-user user-green\">Robert.One</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 01:27\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158641\" href=\"?#comment-158641\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-158610\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158641\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"150202\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158641\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I also had this solution and i got accepted but it took 1 hour to find it during the contest</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158641 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158641 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158641\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158612\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Darek_\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Darek_\" title=\"Specialist Darek_\" class=\"rated-user user-cyan\">Darek_</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 23:12\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158612\" href=\"?#comment-158612\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158612\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"152123\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158612\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks for an informative editorial.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158612 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158612 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158612\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158618\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Mostafa_36a2\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/137637/avatar/28a01293a2b409.jpg'/> </a>\n <div><a href=\"/profile/Mostafa_36a2\" title=\"Specialist Mostafa_36a2\" class=\"rated-user user-cyan\">Mostafa_36a2</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 23:25\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158618\" href=\"?#comment-158618\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"158618\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"158618\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"137637\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158618\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Unbelivable solution for Div2,B by Sick_Coder</p> <pre><code>cin >> n >> m >> k;\n cout << m * (m - 1) / 2 << "\\n";\n\n for (1, m, i)\n \tfor (i + 1, m, j)\n \t\tif (!k)\n \t\t\tcout << i << " " << j << "\\n";\n \t\telse\t\n \t\t\tcout << j << " " << i << "\\n";\n</code></pre></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158618 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158618 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158618\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158631\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mugurelionut\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/63702/avatar/45e4d5390c215090.jpg'/> </a>\n <div><a href=\"/profile/mugurelionut\" title=\"International Master mugurelionut\" class=\"rated-user user-orange\">mugurelionut</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 23:57\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158631\" href=\"?#comment-158631\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158631\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"63702\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158631\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>A very good editorial, indeed! (but please don't forget about Div1E) And the problems were really nice. But I think problem B was tougher than it should have been for its amount of points. I've read some comments saying that problem B had too weak pretests (because so many solutions failed the final system tests). I would have to say that my experience with problem B was the exact opposite. I coded two wrong solutions (which failed some pretest or another) before eventually finding and implementing the right solution. So I'd say that problem B had good pretests :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158631 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158631 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158631\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158635\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/MohammadFatafta\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/148405/avatar/4276577919b9713d.jpg'/> </a>\n <div><a href=\"/profile/MohammadFatafta\" title=\"Specialist MohammadFatafta\" class=\"rated-user user-cyan\">MohammadFatafta</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 00:11\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158635\" href=\"?#comment-158635\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158635\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"148405\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158635\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>now this is a real editorial!! thanks guys :D</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158635 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158635 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158635\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158636\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/matrix\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/matrix\" title=\"Master matrix\" class=\"rated-user user-orange\">matrix</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 00:15\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158636\" href=\"?#comment-158636\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"158636\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"158636\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"16572\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158636\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Hi,</p><p>Great and fast editorial with complete details. </p><p>Thanks very much.</p><p>Edit: I think there is a small typo: "It’s not hard to see that answer for a fixed (i1, j1) is left[i1][j1] * value[2 * j1 – sum_of_elements_from_i1]." I guess you meant count[2 * j1 – sum_of_elements_from_i1].</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158636 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158636 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158636\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158637\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Kyuubi\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/83590/avatar/b87432a652bb276.jpg'/> </a>\n <div><a href=\"/profile/Kyuubi\" title=\"Expert Kyuubi\" class=\"rated-user user-blue\">Kyuubi</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 00:18\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158637\" href=\"?#comment-158637\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158637\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"2\"\r\n data-commentUserId=\"83590\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+2</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158637\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Best Editorials I have seen on codeforces yet! :D</p><p>For Propagating tree, how do we keep track of alternating levels in the arrays we created using DFS ? </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158637 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158637 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158637\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158640\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/k_____k\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/60285/avatar/422359e1ae9d666c.jpg'/> </a>\n <div><a href=\"/profile/k_____k\" title=\"Expert k_____k\" class=\"rated-user user-blue\">k_____k</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 01:07\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158640\" href=\"?#comment-158640\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158640\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"2\"\r\n data-commentUserId=\"60285\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+2</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158640\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Best Editorials Ever ! #thanks to the authors, for posting alternative solutions of contestants also. Great start in 2014. #Looking Forward.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158640 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158640 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158640\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158658\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/sillycross\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/41652/avatar/58966d0c793c6394.jpg'/> </a>\n <div><a href=\"/profile/sillycross\" title=\"Grandmaster sillycross\" class=\"rated-user user-red\">sillycross</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 07:49\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158658\" href=\"?#comment-158658\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158658\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"9\"\r\n data-commentUserId=\"41652\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+9</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158658\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Div1 E can be solved in O(2^24*24) or O(2^24+2^12*n)..</p><p>O(2^24*24): dp[i][s] means the sum of all contributions of subset s where all digits are same as s except the last i digits.. </p><p>O(2^24+2^12*n): the length of word is only 3. We divide the 24 letters in half, calculate the answer for all first 12 letters and all last 12 letters and merge them with brute-force. This can be solved in O(2^24). Then we subtract the words that are counted twice: these words are words that have 2 letters in first half and 1 in second half, or 2 in second half and 1 in first half. Let's consider the first case: for each subset of first 12 letters we check each word whether it has exactly 2 letters in this half, if so, we can say all masks in another half that contains the third letter need to be subtracted by 1. This can be solved in 2^12*(2^12+n). Same algorithm can be used to solve the second case. Although this algorithm runs slower than O(2^24*24) bcuz of its larger constant... </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158658 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158658 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158658\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158663\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/VeniVidiVici\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/VeniVidiVici\" title=\"Candidate Master VeniVidiVici\" class=\"rated-user user-violet\">VeniVidiVici</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 09:39\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158663\" href=\"?#comment-158663\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158663\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"149163\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158663\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Very nice editorial! Disappointed in Div 2B though, really expected the "real" problem rather than just insertion sort but that's what you get for not reading carefully ;)</p><p>However, does anyone have an accepted solution that is "real" (e.g. finds the minimum number of operations necessary and prints such a solution)? I was close but my computer died during contest and I haven't tried so much since (of course you can do O((mn)^2) easily but this is way too slow, there should be a O(n*m^2) solution but again my computer was unable to operate). My approach was to make 2-D boolean array to check if a swap is necessary, but I'm not sure if order of operations will end up being a big problem.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158663 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158663 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158663\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158685\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/LegendaryGrandmaster\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/142091/avatar/a3a5a4b5c26ac419.jpg'/> </a>\n <div><a href=\"/profile/LegendaryGrandmaster\" title=\"Specialist LegendaryGrandmaster\" class=\"rated-user user-cyan\">LegendaryGrandmaster</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 14:34\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158685\" href=\"?#comment-158685\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158685\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"142091\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158685\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>One of the best codeforces editorials ever! Thanks!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158685 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158685 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158685\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158687\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/BENYAM1N\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/84938/avatar/d2ae2657d8898e38.jpg'/> </a>\n <div><a href=\"/profile/BENYAM1N\" title=\"Master BENYAM1N\" class=\"rated-user user-orange\">BENYAM1N</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 15:24\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158687\" href=\"?#comment-158687\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"158687\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"158687\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"84938\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158687\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks a lot. very good contest and good editorial too!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158687 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158687 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158687\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158689\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/JuanMata\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/82548/avatar/a7d69af7b441c6d7.jpg'/> </a>\n <div><a href=\"/profile/JuanMata\" title=\"Expert JuanMata\" class=\"rated-user user-blue\">JuanMata</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 15:47\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158689\" href=\"?#comment-158689\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158689\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"82548\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158689\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>this is one of the best editorials on CF ever!!!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158689 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158689 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158689\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158700\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Vicfred\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/76941/avatar/d067b7433ec39337.jpg'/> </a>\n <div><a href=\"/profile/Vicfred\" title=\"Pupil Vicfred\" class=\"rated-user user-green\">Vicfred</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 16:25\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158700\" href=\"?#comment-158700\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158700\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"11\"\r\n data-commentUserId=\"76941\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+11</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158700\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>The best editorial I've read in a while here, thanks.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158700 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158700 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158700\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158727\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/beecoder\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/beecoder\" title=\"Pupil beecoder\" class=\"rated-user user-green\">beecoder</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 21:13\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158727\" href=\"?#comment-158727\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158727\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"89551\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158727\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Hi, The way I print answers for 'Coder Problem' is as follows. This takes 124 ms. is there a way to print the answers faster ? </p> <pre><code> \tfor (int i = 0 ; i < number ; i ++ ) { \n \t\tfor (int k = 0 ; k < number ; k ++ ) { \n \t\t\tif (flag) {\n \t\t\t\tif ( k % 2 == 1) out.print('.');\n \t\t\t\tif( k% 2 == 0 ) out.print('C');\n \t\t\t} else {\n \t\t\tif ( k % 2 == 1) out.print('C');\n \t\t\tif( k% 2 == 0 ) out.print('.');\t\n \t\t\t}\n \t\t}\n \t\tif (flag) flag = false;\n \t\telse flag = true;\n \t\tout.print("\\n");\n \t}\n \n</code></pre></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158727 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158727 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158727\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158742\" commentParentId=\"158727\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Mostafa_36a2\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/137637/avatar/28a01293a2b409.jpg'/> </a>\n <div><a href=\"/profile/Mostafa_36a2\" title=\"Specialist Mostafa_36a2\" class=\"rated-user user-cyan\">Mostafa_36a2</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/22/2014 14:00\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158742\" href=\"?#comment-158742\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-158727\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158742\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"137637\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158742\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>As the line contains k characters , and every odd lines are identical , also the even ones,</p><p>you can build 2 strings [C.C.C.C] and [.C.C.C.] and print them alternately </p><p>[In my opinion Java is slow language any way ]</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158742 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158742 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158742\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158752\" commentParentId=\"158727\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/t_thirupathi\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/146179/avatar/98c28348196ce4ca.jpg'/> </a>\n <div><a href=\"/profile/t_thirupathi\" title=\"Specialist t_thirupathi\" class=\"rated-user user-cyan\">t_thirupathi</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/22/2014 18:19\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158752\" href=\"?#comment-158752\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-158727\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158752\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"146179\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158752\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Modulo operations are time consuming.</p><p>To check if a number <code>n</code> is odd, you could use <code>if (n & 1)</code></p> <pre><code>for (int i = 0; i < n; i++) {\n for (int j = 0; j < n; j++)\n if ((i + j) & 1)\n out.print('.');\n else \n out.print('C');\n out.print('\\n');\n}\n</code></pre></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158752 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158752 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158752\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158745\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/JuanMata\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/82548/avatar/a7d69af7b441c6d7.jpg'/> </a>\n <div><a href=\"/profile/JuanMata\" title=\"Expert JuanMata\" class=\"rated-user user-blue\">JuanMata</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/22/2014 14:49\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158745\" href=\"?#comment-158745\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"158745\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"158745\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"82548\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158745\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>i think there is a small bug in the <a href=\"http://pastie.org/8651824\">pastie link</a> u posted for the solution of Div1 C problem.</p><p>i submitted almost exact copy of it (<a href=\"/contest/383/submission/5769615\" title=\"Submission 5769615 by JuanMata\">5769615</a>), but got WA#6. then i found the bug, corrected it and resubmitted (<a href=\"/contest/383/submission/5769890\" title=\"Submission 5769890 by JuanMata\">5769890</a>) and got AC.</p><p>referring to my two submissions, corrections in line <strong>68</strong> (last statement of <strong>dfs</strong>) and line <strong>109</strong> (the second call to <strong>update</strong>).</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158745 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158745 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158745\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"615836\" commentParentId=\"158745\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/adityakr007\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/adityakr007\" title=\"Expert adityakr007\" class=\"rated-user user-blue\">adityakr007</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/05/2020 18:54\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-615836\" href=\"?#comment-615836\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-158745\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"615836\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"866209\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-615836\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can you explain what exactly have you done in your submission (<a href=\"/contest/383/submission/5769890\" title=\"Submission 5769890 by JuanMata\">5769890</a>) for this problem?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-615836 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-615836 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-615836\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"629531\" commentParentId=\"615836\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/JuanMata\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/82548/avatar/a7d69af7b441c6d7.jpg'/> </a>\n <div><a href=\"/profile/JuanMata\" title=\"Expert JuanMata\" class=\"rated-user user-blue\">JuanMata</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/25/2020 18:14\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-629531\" href=\"?#comment-629531\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-615836\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"629531\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"82548\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-629531\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>sorry bro i've forgotten ... that was over 6yrs ago now!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-629531 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-629531 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-629531\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158751\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/TempuX\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/30820/avatar/c50adc243ea4e2fa.jpg'/> </a>\n <div><a href=\"/profile/TempuX\" title=\"Specialist TempuX\" class=\"rated-user user-cyan\">TempuX</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/22/2014 17:07\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158751\" href=\"?#comment-158751\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158751\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"30820\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158751\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Hi, I tried to implement the Volcano problem in the way explained in the editorial but I'm getting TLE. Here is my code <a href=\"//codeforces.com/contest/384/submission/5770818\">submission</a> What am I doing wrong ? Thanks anyway.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158751 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158751 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158751\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158811\" commentParentId=\"158751\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/TempuX\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/30820/avatar/c50adc243ea4e2fa.jpg'/> </a>\n <div><a href=\"/profile/TempuX\" title=\"Specialist TempuX\" class=\"rated-user user-cyan\">TempuX</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/23/2014 17:29\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158811\" href=\"?#comment-158811\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-158751\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158811\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"30820\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158811\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Turns out my binary search is causing the problem and I don't see what is wrong with it... I would appreciate any ideas.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158811 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158811 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158811\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159025\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/bboy_drain\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/76710/avatar/e0feb3aa135911d4.jpg'/> </a>\n <div><a href=\"/profile/bboy_drain\" title=\"Expert bboy_drain\" class=\"rated-user user-blue\">bboy_drain</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/25/2014 01:34\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159025\" href=\"?#comment-159025\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159025\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"76710\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159025\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Wow! This really helped me a lot! Very detailed explanations!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159025 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159025 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159025\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159092\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/AlexandruValeanu\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/131651/avatar/1c7d989c45052941.jpg'/> </a>\n <div><a href=\"/profile/AlexandruValeanu\" title=\"Candidate Master AlexandruValeanu\" class=\"rated-user user-violet\">AlexandruValeanu</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/25/2014 21:27\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159092\" href=\"?#comment-159092\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159092\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"131651\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159092\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>It was by far your best round on Codeforces, <a class=\"rated-user user-blue\" href=\"/profile/fchirica\" title=\"Expert fchirica\">fchirica</a>. The problems were great, very different one from the other and some of them didn't require any algorithmic skills at all. Good job!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159092 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159092 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159092\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159261\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lawsonh\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/lawsonh\" title=\"Expert lawsonh\" class=\"rated-user user-blue\">lawsonh</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/28/2014 06:33\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159261\" href=\"?#comment-159261\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"159261\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"159261\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"55047\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159261\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>for div1 383C should end[5] = 7? edit: nvm drew the tree wrong</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159261 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159261 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159261\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159474\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/tiagonapoli\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/150060/avatar/6615fcab66b23361.jpg'/> </a>\n <div><a href=\"/profile/tiagonapoli\" title=\"Candidate Master tiagonapoli\" class=\"rated-user user-violet\">tiagonapoli</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/30/2014 22:28\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159474\" href=\"?#comment-159474\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159474\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"150060\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159474\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Great Editorial! Thanks so much, i've learned a lot!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159474 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159474 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159474\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159707\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lchf\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/60496/avatar/e9939e755252ec16.jpg'/> </a>\n <div><a href=\"/profile/lchf\" title=\"Candidate Master lchf\" class=\"rated-user user-violet\">lchf</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/02/2014 17:28\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159707\" href=\"?#comment-159707\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159707\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"60496\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159707\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Amazing solution by Endagorion.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159707 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159707 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159707\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"177400\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/sourabh912\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/57335/avatar/bf83b9340e3cbb17.jpg'/> </a>\n <div><a href=\"/profile/sourabh912\" title=\"Specialist sourabh912\" class=\"rated-user user-cyan\">sourabh912</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/12/2014 20:39\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-177400\" href=\"?#comment-177400\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"177400\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"57335\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-177400\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In Div 1C problem, I could not understand how it can be solved using single fenwick tree from the solution link in the editorial. Can anyone please help.</p><p>Thanks</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-177400 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-177400 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-177400\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"291157\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/l_Love_KFC\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/258117/avatar/bbaec3ce1613f5bd.jpg'/> </a>\n <div><a href=\"/profile/l_Love_KFC\" title=\"Expert l_Love_KFC\" class=\"rated-user user-blue\">l_Love_KFC</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Apr/29/2016 08:23\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-291157\" href=\"?#comment-291157\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"291157\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"258117\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-291157\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In Div.1 A I didn't catch the point that in 1st, quote : "If we put i before j, no additional cost will be added. Since j is in right of i and i only adds cost when it finds elements in left of i, j won’t be affected when processing i." Won't we lose milk if we put firstly i, in case of that j sees that and loses milk? Or am I misunderstanding the task? </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-291157 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-291157 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-291157\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"309434\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/haleyk100198\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/416324/avatar/f2d97d505af17e9d.jpg'/> </a>\n <div><a href=\"/profile/haleyk100198\" title=\"Candidate Master haleyk100198\" class=\"rated-user user-violet\">haleyk100198</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/11/2016 06:32\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-309434\" href=\"?#comment-309434\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"309434\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"416324\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-309434\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I wonder how the problem Div1C can be converted to a segment tree lazy propagation implementation question, for trees like (1-2 2-3 3-4 4-5 .... 9999-E4) how can we achieve O(log N) update time?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-309434 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-309434 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-309434\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"310847\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/my_new_handle\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/233736/avatar/24128c61b65e3262.jpg'/> </a>\n <div><a href=\"/profile/my_new_handle\" title=\"Candidate Master my_new_handle\" class=\"rated-user user-violet\">my_new_handle</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/20/2016 14:49\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-310847\" href=\"?#comment-310847\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"310847\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"233736\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-310847\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>а зачем в таске б массив он влияет как-то?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-310847 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-310847 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-310847\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"332763\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/rhezo\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/305605/avatar/aa59e9c2ec688c6a.jpg'/> </a>\n <div><a href=\"/profile/rhezo\" title=\"Candidate Master rhezo\" class=\"rated-user user-violet\">rhezo</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Dec/24/2016 07:56\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-332763\" href=\"?#comment-332763\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"332763\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"305605\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-332763\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I'm getting Runtime Error on test 44 in <a href=\"//codeforces.com/problemset/problem/383/C\">Propogating Tree</a>. </p><p>This is because of stack overflow right? That test has N = 2e5 and for a straight chain of nodes, I'll get a runtime error with a recursive DFS right? What to do in such cases? </p><p>I can write an iterative DFS, but I do HLD recursively too and I'm not quite sure if I can write an iterative HLD. </p><p>Can anyone tell me what to do in such cases? I'm assuming that I got the runtime error due to stackoverflow from DFS.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-332763 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-332763 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-332763\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"346070\" commentParentId=\"332763\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/yinanzhu\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/520731/avatar/d61a58bf5df54146.jpg'/> </a>\n <div><a href=\"/profile/yinanzhu\" title=\"Expert yinanzhu\" class=\"rated-user user-blue\">yinanzhu</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/26/2017 07:18\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-346070\" href=\"?#comment-346070\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-332763\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"346070\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"520731\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-346070\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I used recursive dfs and passed all test case. Test 44 cost 1.5 s</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-346070 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-346070 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-346070\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"387028\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/blue__legend\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/blue__legend\" title=\"Expert blue__legend\" class=\"rated-user user-blue\">blue__legend</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/23/2017 07:16\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-387028\" href=\"?#comment-387028\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"387028\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"284949\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-387028\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>How to solve DIV 1 C using one fenwick or segment tree. The code link given in editorial is not working.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-387028 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-387028 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-387028\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"757423\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Ausmosian\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Ausmosian\" title=\"Expert Ausmosian\" class=\"rated-user user-blue\">Ausmosian</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/05/2021 15:05\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-757423\" href=\"?#comment-757423\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"757423\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"727283\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-757423\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>[<a href=\"https://codeforces.com/contest/383/problem/C\">384E — Propagating tree</a>] Can also be solved using Square Root Decomposition. <a href=\"https://codeforces.com/contest/383/submission/106526543\">Submission</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-757423 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-757423 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-757423\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"838255\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/3hill\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1621900/avatar/478297db63bad207.jpg'/> </a>\n <div><a href=\"/profile/3hill\" title=\"Expert 3hill\" class=\"rated-user user-blue\">3hill</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/11/2021 17:02\">2 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-838255\" href=\"?#comment-838255\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"838255\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1621900\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-838255\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I am Getting MLE on TC-53<br />Can someone review my code and figure out the issue ,Thanks</p> <ul> <li><a href=\"https://codeforces.com/contest/383/problem/C\">Problem</a></li> <li><a href=\"https://codeforces.com/contest/383/submission/128510633\">My code</a></li> </ul></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-838255 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-838255 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-838255\">\r\n </ul>\r\n</div>\r\n <br/>\r\n\r\n<div id=\"editBox-10547\" style=\"width:50em;display:none;\">\r\n <div class=\"previewBody\" style=\"border: 1px solid #d4d4d4; margin-bottom: 0.5em; padding: 0.25em; display:none;\"> </div>\r\n <div style=\"width: 1px\"> </div>\r\n <div class=\"commentLocale\" style=\"position: relative; top: 0.5em;left:4px;display: none;\">\r\n <input type=\"radio\" name=\"locale\" value=\"en\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In English</span>\r\n <input style=\"margin-left:1em\" type=\"radio\" name=\"locale\" value=\"ru\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In Russian</span>\r\n </div>\r\n <textarea data-drafts-id=\"CommentReplyFrame\" class=\"wysiwyg\" name=\"editContent\" rows=\"20\" style=\"width:99%;\"></textarea>\r\n <div class=\"error error__content\"></div>\r\n <div style=\"text-align:center;\">\r\n <input type=\"button\" name=\"preview\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Preview\"/>\r\n <input type=\"button\" name=\"save\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Save\"/>\r\n </div>\r\n</div>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n\r\nvar firstPreview10547 = true;\r\nvar lastPreviewContent10547 = '';\r\n\r\nif (!window.moveCommentRevision) {\r\n moveCommentRevision = function(e, dir) {\r\n var p = e.parent();\r\n var revisionCount = parseInt(p.attr(\"revisionCount\"));\r\n var revision = parseInt(p.attr(\"revision\"));\r\n var next = revision + dir;\r\n var commentId = p.attr(\"commentId\");\r\n if (next >= 1 && next <= revisionCount) {\r\n $.post(\r\n \"/data/comment-data\",\r\n {action: \"revision\", commentId: commentId, revision: next},\r\n function(json) {\r\n if (json.success == \"true\") {\r\n var parentDiv = e;\r\n\r\n while (parentDiv !== null && (parentDiv[0].nodeName.toLowerCase() !== \"td\" || !parentDiv.hasClass(\"right\"))) {\r\n parentDiv = parentDiv.parent();\r\n }\r\n\r\n if (parentDiv === null) {\r\n return;\r\n }\r\n\r\n parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\").html(json.content);\r\n Codeforces.setupSpoilers(parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\"));\r\n p.attr(\"revision\", next);\r\n p.find(\"span.revision\").text(next);\r\n if (next == 1) {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"visible\");\r\n }\r\n if (next == revisionCount) {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"visible\");\r\n }\r\n\r\n window.updateTypography();\r\n MathJax.Hub.Typeset();\r\n } else {\r\n alert(e.error);\r\n }\r\n },\r\n \"json\"\r\n );\r\n }\r\n };\r\n}\r\n\r\n$(\"div[commentableId=10547] a.leftRevision\").click(function () {\r\n window.moveCommentRevision($(this), -1);\r\n return false;\r\n});\r\n\r\n$(\"div[commentableId=10547] a.rightRevision\").click(function () {\r\n window.moveCommentRevision($(this), +1);\r\n return false;\r\n});\r\n\r\n\r\n\r\n });\n </script>\n\r\n\r\n <script src=\"//codeforces.org/s/81027/js/swfobject-2.2.min.js\" type=\"text/javascript\"></script>\n <script src=\"//codeforces.org/s/81027/js/ftaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n if (window.evercookie) {\n var ec = new evercookie({\n history: false,\n silverlight: false,\n baseurl: '',\n asseturi: '/assets',\n phpuri: '/2fdcd78',\n pngPath: '/eps',\n etagPath: '/ees',\n cachePath: '/ecs'\n });\n\n var randomNumber = function () {\n return Math.random().toString(36).substr(2);\n };\n\n var randomToken = function () {\n return (randomNumber() + randomNumber()).substring(0, 18);\n };\n\n window._ftaa = \"\";\n\n ec.get(\"70a7c28f3de\", function (value) {\n window._ftaa = value;\n if (!window._ftaa) {\n window._ftaa = randomToken();\n ec.set(\"70a7c28f3de\", window._ftaa);\n }\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n } else {\n window._ftaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\n <script src=\"//codeforces.org/s/81027/js/bfaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n var fpCallback = function() {\n Fingerprint2.get({}, function(components) {\n window._bfaa = Fingerprint2.x64hash128(components.map(function (pair) { return pair.value }).join(), 31);\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n };\n if (typeof Fingerprint2 !== 'undefined') {\n if (window.requestIdleCallback) {\n requestIdleCallback(fpCallback)\n } else {\n setTimeout(fpCallback, 500)\n }\n } else {\n window._bfaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"a.new-root-comment\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n\r\n $(\".comment-table .reply a\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".vote-for-comment\").mouseover(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").mouseout(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").click(function () {\r\n var vote = $(this);\r\n var commentId = $(this).parent().attr(\"commentid\");\r\n var commentRating = $(this).parent().attr(\"data-commentRating\");\r\n var direction = $(this).attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n $.post(\"/data/comment/vote\", {commentId: commentId, _tta: Codeforces.tta(), vote: direction, commentRating: commentRating}, function(data) {\r\n if (direction != 0 && !ownComment && data[\"success\"] == \"true\") {\r\n vote.parent().find(\".vote-for-comment\").attr(\"voteDirection\", 0);\r\n if (direction == 1)\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n else {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.closest(\".CommentVoteFrame\").find(\".ComplaintFrame\").css(\"display\", \"inline-block\");\r\n }\r\n vote.find(\"img\").attr(\"popacity\", \"1.0\");\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n vote.parent().find(\".commentRating\").html(data[\"commentRating\"]);\r\n }\r\n Codeforces.showMessage(data[\"message\"]);\r\n }, \"json\");\r\n return false;\r\n });\r\n\r\n $(\".negative-comment-vote\").closest(\".comment-table\").addClass(\"comment-bad\");\r\n\r\n $(\".troll-comment-vote\").closest(\".comment\").css(\"display\", \"none\");\r\n\r\n $(\".too-negative-comment-vote\").closest(\".comment-table\").each(function () {\r\n var e = $(this);\r\n e.addClass(\"comment-too-bad\");\r\n var commentId = e.attr(\"commentId\");\r\n $(\"<div class='bad-comment-replacement ttypography'>The comment is hidden because of too negative feedback, click <a href=# class=show-bad-comment-link>here</a> to view it</div>\").appendTo(\r\n e.find(\".right\")\r\n );\r\n e.find(\".comment-content\").hide();\r\n e.find(\".show-bad-comment-link\").click(function () {\r\n e.find(\".comment-content\").show();\r\n e.find(\".bad-comment-replacement\").hide();\r\n return false;\r\n });\r\n });\r\n });\n </script>\n </div>\r\n\r\n <style type=\"text/css\">\r\n .new-comments-box {\r\n padding: 0.5em;\r\n width: 22px;\r\n font-size: 1.3rem;\r\n font-weight: bold !important;\r\n\r\n position: fixed;\r\n top: 40%;\r\n right: 0;\r\n opacity: 0.2;\r\n color: white;\r\n text-align: center;\r\n\r\n border: 1px solid #222;\r\n background-color: #888 !important;\r\n border-radius: 3px;\r\n -moz-border-radius: 3px;\r\n -webkit-border-radius: 3px;\r\n }\r\n\r\n .new-comments-box:hover {\r\n opacity: 1;\r\n }\r\n\r\n .new-comments-box .dir:hover {\r\n background: #3B5998 !important;\r\n cursor: pointer;\r\n }\r\n </style>\r\n\r\n <div class=\"new-comments-box\" data-position=\"outside\" data-index=\"-1\" style=\"display: none;\">\r\n <div class=\"up dir\" title=\"Ctrl+Up\">↑<hr/>\r\n </div>\r\n <div class=\"info\" title=\"New comments\"></div>\r\n <div class=\"down dir\" title=\"Ctrl+Down\">\r\n <hr/>↓\r\n </div>\r\n </div>\r\n\r\n <script>\r\n $(\".show-archived-checkbox\").change(function () {\r\n const checked = $(this).is(\":checked\");\r\n $.post(\"/data/comment-data\", {action: \"setShowArchived\", checked}, function (json) {\r\n if (json[\"success\"] !== \"true\") {\r\n alert(json[\"error\"]);\r\n } else {\r\n if (checked) {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are now displayed\")\r\n } else {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are no longer displayed\")\r\n }\r\n }\r\n });\r\n return false;\r\n });\r\n\r\n function gotoComment(direction) {\r\n var box = $(\".new-comments-box\");\r\n var index = parseInt(box.attr(\"data-index\"));\r\n if (index == -1)\r\n index = 0;\r\n else\r\n index = Math.max(0, Math.min(parseInt(box.find(\".info\").text()) - 1, index + direction));\r\n box.attr(\"data-index\", index);\r\n var comment = $($(\".comment .highlight-blue[commentId]\").get(index));\r\n $('html, body').animate({\r\n 'scrollTop': Math.max(0, comment.offset().top - ($(window).height() - comment.height()) / 2)\r\n });\r\n return false;\r\n }\r\n\r\n $(\".new-comments-box .down\").click(function () {\r\n return gotoComment(1);\r\n });\r\n\r\n $(\".new-comments-box .up\").click(function () {\r\n return gotoComment(-1);\r\n });\r\n\r\n $(document).keydown(function (e) {\r\n var code = (e.keyCode ? e.keyCode : e.which);\r\n if (e.ctrlKey) {\r\n if (code == 38 || code == 40) {\r\n gotoComment(code - 39);\r\n }\r\n }\r\n });\r\n\r\n var newCommentCount = $(\".comment .highlight-blue[commentId]\").length;\r\n if (newCommentCount > 0) {\r\n $(\".new-comments-box .info\").text(newCommentCount);\r\n $(\".new-comments-box\").show();\r\n }\r\n\r\n $('table.comment-table').mouseenter(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").addClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n\r\n $('table.comment-table').mouseleave(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").removeClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n </script>\r\n\r\n\r\n\r\n <script>\r\n function adjustTopicComplainFrames() {\r\n let topicIds = [];\r\n\r\n $(\".has-topic-id\").each(function () {\r\n const $this = $(this);\r\n const topicId = $this.attr(\"topicId\");\r\n if (topicId) {\r\n topicIds.push(topicId);\r\n }\r\n });\r\n\r\n $.post(\"/data/topics\", {\r\n action: \"findComplainableTopicIds\",\r\n topicIds: topicIds.join(\",\")\r\n }, function (json) {\r\n if (json[\"success\"] === \"true\") {\r\n for (const topicId of json[\"complainableTopicIds\"].split(\",\")) {\r\n $(\".has-topic-id[topicId=\" + topicId + \"]\").each(function () {\r\n $(this).find(\".meta .ComplaintFrame\").css(\"display\", \"inline-block\");\r\n });\r\n }\r\n }\r\n }, \"json\");\r\n }\r\n\r\n $(function () {\r\n adjustTopicComplainFrames();\r\n })\r\n </script>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-10531\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 10531, _tta: Codeforces.tta(), topicRevisionId: 36233, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-10531\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 10531, _tta: Codeforces.tta(), topicRevisionId: 36233, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n </div>\r\n </div>\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 22:13:02</span> (h1).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/81027/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/81027/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/81027/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/81027/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-81027.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'81287584a8369d92',t:'MTY5NjcwNTk4Mi42NDcwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"}}},{"rowIdx":1943,"cells":{"problem_id":{"kind":"string","value":"384E"},"contest":{"kind":"string","value":"384"},"problem":{"kind":"string","value":"E"},"lang":{"kind":"string","value":"en"},"problem_title":{"kind":"string","value":"E. Propagating tree"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">E. Propagating tree</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Iahub likes trees very much. Recently he discovered an interesting tree named propagating tree. The tree consists of <span class=\"tex-span\"><i>n</i></span> nodes numbered from <span class=\"tex-span\">1</span> to <span class=\"tex-span\"><i>n</i></span>, each node <span class=\"tex-span\"><i>i</i></span> having an initial value <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span>. The root of the tree is node <span class=\"tex-span\">1</span>.</p><p>This tree has a special property: when a value <span class=\"tex-span\"><i>val</i></span> is added to a value of node <span class=\"tex-span\"><i>i</i></span>, the value -<span class=\"tex-span\"><i>val</i></span> is added to values of all the children of node <span class=\"tex-span\"><i>i</i></span>. Note that when you add value -<span class=\"tex-span\"><i>val</i></span> to a child of node <span class=\"tex-span\"><i>i</i></span>, you also add -(-<span class=\"tex-span\"><i>val</i></span>) to all children of the child of node <span class=\"tex-span\"><i>i</i></span> and so on. Look an example explanation to understand better how it works.</p><p>This tree supports two types of queries:</p><ul> <li> \"<span class=\"tex-span\">1</span> <span class=\"tex-span\"><i>x</i></span> <span class=\"tex-span\"><i>val</i></span>\" — <span class=\"tex-span\"><i>val</i></span> is added to the value of node <span class=\"tex-span\"><i>x</i></span>; </li><li> \"<span class=\"tex-span\">2</span> <span class=\"tex-span\"><i>x</i></span>\" — print the current value of node <span class=\"tex-span\"><i>x</i></span>. </li></ul><p>In order to help Iahub understand the tree better, you must answer <span class=\"tex-span\"><i>m</i></span> queries of the preceding type.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains two integers <span class=\"tex-span\"><i>n</i></span> and <span class=\"tex-span\"><i>m</i></span> <span class=\"tex-span\">(1 ≤ <i>n</i>, <i>m</i> ≤ 200000)</span>. The second line contains <span class=\"tex-span\"><i>n</i></span> integers <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub></span>, <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">2</sub></span>, ..., <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>n</i></sub></span> <span class=\"tex-span\">(1 ≤ <i>a</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 1000)</span>. Each of the next <span class=\"tex-span\"><i>n</i>–1</span> lines contains two integers <span class=\"tex-span\"><i>v</i><sub class=\"lower-index\"><i>i</i></sub></span> and <span class=\"tex-span\"><i>u</i><sub class=\"lower-index\"><i>i</i></sub></span> <span class=\"tex-span\">(1 ≤ <i>v</i><sub class=\"lower-index\"><i>i</i></sub>, <i>u</i><sub class=\"lower-index\"><i>i</i></sub> ≤ <i>n</i>)</span>, meaning that there is an edge between nodes <span class=\"tex-span\"><i>v</i><sub class=\"lower-index\"><i>i</i></sub></span> and <span class=\"tex-span\"><i>u</i><sub class=\"lower-index\"><i>i</i></sub></span>.</p><p>Each of the next <span class=\"tex-span\"><i>m</i></span> lines contains a query in the format described above. It is guaranteed that the following constraints hold for all queries: <span class=\"tex-span\">1 ≤ <i>x</i> ≤ <i>n</i>, 1 ≤ <i>val</i> ≤ 1000</span>.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>For each query of type two (print the value of node <span class=\"tex-span\"><i>x</i></span>) you must print the answer to the query on a separate line. The queries must be answered in the order given in the input.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>5 5<br/>1 2 1 1 2<br/>1 2<br/>1 3<br/>2 4<br/>2 5<br/>1 2 3<br/>1 1 2<br/>2 1<br/>2 2<br/>2 4<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>3<br/>3<br/>0<br/></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>The values of the nodes are <span class=\"tex-span\">[1, 2, 1, 1, 2]</span> at the beginning.</p><p>Then value <span class=\"tex-span\">3</span> is added to node <span class=\"tex-span\">2</span>. It propagates and value -<span class=\"tex-span\">3</span> is added to it's sons, node <span class=\"tex-span\">4</span> and node <span class=\"tex-span\">5</span>. Then it cannot propagate any more. So the values of the nodes are <span class=\"tex-span\">[1, 5, 1, - 2, - 1]</span>.</p><p>Then value <span class=\"tex-span\">2</span> is added to node <span class=\"tex-span\">1</span>. It propagates and value -<span class=\"tex-span\">2</span> is added to it's sons, node <span class=\"tex-span\">2</span> and node <span class=\"tex-span\">3</span>. From node <span class=\"tex-span\">2</span> it propagates again, adding value <span class=\"tex-span\">2</span> to it's sons, node <span class=\"tex-span\">4</span> and node <span class=\"tex-span\">5</span>. Node <span class=\"tex-span\">3</span> has no sons, so it cannot propagate from there. The values of the nodes are <span class=\"tex-span\">[3, 3, - 1, 0, 1]</span>.</p><p>You can see all the definitions about the tree at the following link: <span class=\"tex-font-style-tt\">http://en.wikipedia.org/wiki/Tree_(graph_theory)</span></p></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"81f23fbd801c6cb1fe561231d70f3813\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - E - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"2080925ccc752dc6d7cc9e06390b1986ca0eae39\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - E - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/73366/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/73366/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/73366/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/73366/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/73366/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/73366/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/73366/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/73366/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/73366/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/73366/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/73366/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/73366/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/73366/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/73366/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/sidebar-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/a037fe51637846d9c7c725713cd840ea/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='81f23fbd801c6cb1fe561231d70f3813'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/73366/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/73366/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fcontest%2F384%2Fproblem%2FE%3Flocale%3Den\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"current\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='81f23fbd801c6cb1fe561231d70f3813'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:100%;\"><a style=\"color: black\" href=\"/contest/384\">Codeforces Round 225 (Div. 2)</a></th>\n </tr>\n <tr>\n <td class=\"left bottom\" colspan=\"1\"><span class=\"contest-state-phase\">Finished</span></td>\n </tr>\n </tbody>\n </table>\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Practice?\n <div class=\"top-links\">\n </div>\n </div>\n<div>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Want to solve the contest problems after the official contest ends? Just register for practice and you will be able to submit solutions.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"\" method=\"post\"><input type='hidden' name='csrf_token' value='81f23fbd801c6cb1fe561231d70f3813'/>\r\n <input type=\"hidden\" name=\"action\" value=\"registerForPractice\"/>\r\n <input type=\"submit\" name=\"submit\" value=\"Register for practice\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div> \r\n</div>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox ContestVirtualFrame borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Virtual participation <i class=\"sidebar-caption-icon las la-angle-down\"></i>\r\n\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\" \"\r\n\r\n data-page-url=\"/data/sidebarFrames\"\r\n\r\n>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests.\n\nIf you've seen these problems, a virtual contest is not for you - solve these problems in the archive.\n\nIf you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.\n\nNever use someone else's code, read the tutorials or communicate with other person during a virtual contest.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"/contest/384/virtual\" method=\"get\">\r\n <input type=\"submit\" name=\"submit\" value=\"Start virtual contest\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div>\r\n</div>\r\n <script>\r\n $(function () {\r\n $(\".ContestVirtualFrame .sidebar-caption-icon\").click(function() {\r\n $(this).toggleClass(\"la-angle-down la-angle-right\");\r\n const $target = $(this).parent().next();\r\n $target.toggle();\r\n const dataPageUrl = $target.attr(\"data-page-url\");\r\n const collapsed = $(this).hasClass(\"la-angle-right\");\r\n const params = {\r\n action: \"setCollapsed\",\r\n sidebarFrameSimpleClassName: \"ContestVirtualFrame\",\r\n collapsed\r\n };\r\n $.each($target[0].attributes, function(i, a) {\r\n const name = a.name;\r\n if (name.startsWith(\"data-extra-key-\")) {\r\n const key = a.value;\r\n const keyIndex = parseInt(name.substring(\"data-extra-key-\".length));\r\n const value = $target.attr(\"data-extra-value-\" + keyIndex);\r\n params[key] = value;\r\n }\r\n });\r\n $.post(dataPageUrl, params, function (result) {\r\n if (result[\"success\"] !== \"true\") {\r\n Codeforces.showMessage(\"Failed to save collapsed state.\");\r\n }\r\n }, \"json\");\r\n return false;\r\n });\r\n })\r\n </script>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Problem tags\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Heaps, binary search trees, segment trees, hash tables, etc\">\r\n data structures\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Dfs and similar\">\r\n dfs and similar\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Graphs\">\r\n graphs\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Trees\">\r\n trees\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Difficulty\">\r\n *2000\r\n</span>\r\n </div>\n <div style=\"clear:both;text-align:right;font-size:1.1rem;\">\r\n <span title=\"Please login into the Codeforces\" class=\"notice\">No tag edit access</span>\r\n </div>\r\n</div>\r\n </div>\n\r\n<form id=\"addTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='81f23fbd801c6cb1fe561231d70f3813'/>\r\n <input name=\"action\" type=\"hidden\" value=\"addTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"5721\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<form id=\"removeTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='81f23fbd801c6cb1fe561231d70f3813'/>\r\n <input name=\"action\" type=\"hidden\" value=\"removeTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"5721\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<script type=\"text/javascript\">\r\n $(\".tag-box img\").click(function () {\r\n var tagName = $(this).attr(\"value\");\r\n Codeforces.confirm(\"Are you sure you want to remove this tag?\", function () {\r\n $(\"#removeTagForm input[name=tagName]\").val(tagName);\r\n $(\"#removeTagForm\").submit();\r\n }, function () {\r\n }, \"Yes\", \"No\");\r\n });\r\n\r\n $(\"#addTagLink\").click(function () {\r\n $(this).hide();\r\n $(\"#addTagLabel\").show();\r\n return false;\r\n });\r\n\r\n $(\"#addTagSelect\").change(function () {\r\n var tagName = $(this).val();\r\n if (tagName === \"\") {\r\n $(\"#addTagLabel\").hide();\r\n $(\"#addTagLink\").show();\r\n } else {\r\n $(\"#addTagForm input[name=tagName]\").val(tagName);\r\n $(\"#addTagForm\").submit();\r\n }\r\n });\r\n</script>\r\n\r\n<style type=\"text/css\">\r\n#new-resource-form tr td {\r\npadding-top: 0.5em;\r\n}\r\n#new-resource-form input:not([type=\"submit\"]) {\r\nfont-size: 0.8em;\r\n}\r\n#new-resource-form select {\r\nfont-size: 0.8em;\r\n}\r\n.new-resource-error {\r\nfont-size: 0.8em;\r\n}\r\n.resource-locale {\r\ncolor: #666;\r\nfont-family: Consolas, \"Andale Mono WT\", \"Andale Mono\", \"Lucida Console\", \"Lucida Sans Typewriter\", \"DejaVu Sans Mono\", \"Bitstream Vera Sans Mono\", \"Liberation Mono\", \"Nimbus Mono L\", Monaco, \"Courier New\", Courier, monospace;\r\n}\r\n</style>\r\n<div class=\"roundbox sidebox sidebar-menu borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Contest materials\n<div class=\"top-links\">\n</div>\n</div>\n<ul>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/10448\" title=\"Codeforces Round #225\" target=\"_blank\">Codeforces Round #225</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"2168:2169\" resourceName=\"Announcement\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/10476\" title=\"Codeforces Round #225 — Editorial\" target=\"_blank\">Tutorial <span class=\"resource-locale\">(en)</span></a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"2173\" resourceName=\"Codeforces Round #225 — Editorial\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n</ul>\r\n</div></div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li class=\"current selectedLava\"><a\r\n href=\"/contest/384\">Problems</a></li>\r\n <li><a\r\n href=\"/contest/384/submit\">Submit Code</a></li>\r\n <li><a\r\n href=\"/contest/384/my\">My Submissions</a></li>\r\n <li><a\r\n href=\"/contest/384/status\">Status</a></li>\r\n <li><a\r\n href=\"/contest/384/hacks\">Hacks</a></li>\r\n <li><a\r\n href=\"/contest/384/room/1\">Room</a></li>\r\n <li><a\r\n href=\"/contest/384/standings\">Standings</a></li>\r\n <li><a\r\n href=\"/contest/384/customtest\">Custom Invocation</a></li>\r\n</ul>\r\n</div>\n\r\n <style>\r\n #facebox .content:has(.diff-popup) {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n }\r\n\r\n .testCaseMarker {\r\n position: absolute;\r\n font-weight: bold;\r\n font-size: 1rem;\r\n }\r\n\r\n .diff-popup {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n display: none;\r\n overflow: auto;\r\n }\r\n\r\n .input-output-copier {\r\n font-size: 1.2rem;\r\n float: right;\r\n color: #888 !important;\r\n cursor: pointer;\r\n border: 1px solid rgb(185, 185, 185);\r\n padding: 3px;\r\n margin: 1px;\r\n line-height: 1.1rem;\r\n text-transform: none;\r\n }\r\n\r\n .input-output-copier:hover {\r\n background-color: #def;\r\n }\r\n\r\n .test-explanation textarea {\r\n width: 100%;\r\n height: 1.5em;\r\n }\r\n\r\n .pending-submission-message {\r\n color: darkorange !important;\r\n }\r\n </style>\r\n <script>\r\n const OPENING_SPACE = String.fromCharCode(1001);\r\n const CLOSING_SPACE = String.fromCharCode(1002);\r\n\r\n const nodeToText = function (node, pre) {\r\n let result = [];\r\n\r\n if (node.tagName === \"SCRIPT\" || node.tagName === \"math\"\r\n || (node.classList && node.classList.contains(\"input-output-copier\")))\r\n return [];\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(OPENING_SPACE);\r\n }\r\n\r\n if (node.nodeType === Node.TEXT_NODE) {\r\n let s = node.textContent;\r\n if (!pre) {\r\n s = s.replace(/\\s+/g, \" \");\r\n }\r\n if (s.length > 0) {\r\n result.push(s);\r\n }\r\n }\r\n\r\n if (pre && node.tagName === \"BR\") {\r\n result.push(\"\\n\");\r\n }\r\n\r\n node.childNodes.forEach(function (child) {\r\n result.push(nodeToText(child, node.tagName === \"PRE\").join(\"\"));\r\n });\r\n\r\n if (node.tagName === \"DIV\"\r\n || node.tagName === \"P\"\r\n || node.tagName === \"PRE\"\r\n || node.tagName === \"UL\"\r\n || node.tagName === \"LI\"\r\n ) {\r\n result.push(\"\\n\");\r\n }\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(CLOSING_SPACE);\r\n }\r\n\r\n return result;\r\n }\r\n\r\n const isSpecial = function (c) {\r\n return c === ',' || c === '.' || c === ';' || c === ')' || c === ' ';\r\n }\r\n\r\n const convertStatementToText = function(statmentNode) {\r\n const text = nodeToText(statmentNode, false).join(\"\").replace(/ +/g, \" \").replace(/\\n\\n+/g, \"\\n\\n\");\r\n let result = [];\r\n for (let i = 0; i < text.length; i++) {\r\n const c = text.charAt(i);\r\n if (c === OPENING_SPACE) {\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"E\" data-uuid=\"ps_44a451f02898cfd2c1f740cb7b6d1e616f7140e1\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">E. Propagating tree</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Iahub likes trees very much. Recently he discovered an interesting tree named propagating tree. The tree consists of <span class=\"tex-span\"><i>n</i></span> nodes numbered from <span class=\"tex-span\">1</span> to <span class=\"tex-span\"><i>n</i></span>, each node <span class=\"tex-span\"><i>i</i></span> having an initial value <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span>. The root of the tree is node <span class=\"tex-span\">1</span>.</p><p>This tree has a special property: when a value <span class=\"tex-span\"><i>val</i></span> is added to a value of node <span class=\"tex-span\"><i>i</i></span>, the value -<span class=\"tex-span\"><i>val</i></span> is added to values of all the children of node <span class=\"tex-span\"><i>i</i></span>. Note that when you add value -<span class=\"tex-span\"><i>val</i></span> to a child of node <span class=\"tex-span\"><i>i</i></span>, you also add -(-<span class=\"tex-span\"><i>val</i></span>) to all children of the child of node <span class=\"tex-span\"><i>i</i></span> and so on. Look an example explanation to understand better how it works.</p><p>This tree supports two types of queries:</p><ul> <li> "<span class=\"tex-span\">1</span> <span class=\"tex-span\"><i>x</i></span> <span class=\"tex-span\"><i>val</i></span>" — <span class=\"tex-span\"><i>val</i></span> is added to the value of node <span class=\"tex-span\"><i>x</i></span>; </li><li> "<span class=\"tex-span\">2</span> <span class=\"tex-span\"><i>x</i></span>" — print the current value of node <span class=\"tex-span\"><i>x</i></span>. </li></ul><p>In order to help Iahub understand the tree better, you must answer <span class=\"tex-span\"><i>m</i></span> queries of the preceding type.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains two integers <span class=\"tex-span\"><i>n</i></span> and <span class=\"tex-span\"><i>m</i></span> <span class=\"tex-span\">(1 ≤ <i>n</i>, <i>m</i> ≤ 200000)</span>. The second line contains <span class=\"tex-span\"><i>n</i></span> integers <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub></span>, <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">2</sub></span>, ..., <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>n</i></sub></span> <span class=\"tex-span\">(1 ≤ <i>a</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 1000)</span>. Each of the next <span class=\"tex-span\"><i>n</i>–1</span> lines contains two integers <span class=\"tex-span\"><i>v</i><sub class=\"lower-index\"><i>i</i></sub></span> and <span class=\"tex-span\"><i>u</i><sub class=\"lower-index\"><i>i</i></sub></span> <span class=\"tex-span\">(1 ≤ <i>v</i><sub class=\"lower-index\"><i>i</i></sub>, <i>u</i><sub class=\"lower-index\"><i>i</i></sub> ≤ <i>n</i>)</span>, meaning that there is an edge between nodes <span class=\"tex-span\"><i>v</i><sub class=\"lower-index\"><i>i</i></sub></span> and <span class=\"tex-span\"><i>u</i><sub class=\"lower-index\"><i>i</i></sub></span>.</p><p>Each of the next <span class=\"tex-span\"><i>m</i></span> lines contains a query in the format described above. It is guaranteed that the following constraints hold for all queries: <span class=\"tex-span\">1 ≤ <i>x</i> ≤ <i>n</i>, 1 ≤ <i>val</i> ≤ 1000</span>.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>For each query of type two (print the value of node <span class=\"tex-span\"><i>x</i></span>) you must print the answer to the query on a separate line. The queries must be answered in the order given in the input.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>5 5<br />1 2 1 1 2<br />1 2<br />1 3<br />2 4<br />2 5<br />1 2 3<br />1 1 2<br />2 1<br />2 2<br />2 4<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>3<br />3<br />0<br /></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>The values of the nodes are <span class=\"tex-span\">[1, 2, 1, 1, 2]</span> at the beginning.</p><p>Then value <span class=\"tex-span\">3</span> is added to node <span class=\"tex-span\">2</span>. It propagates and value -<span class=\"tex-span\">3</span> is added to it's sons, node <span class=\"tex-span\">4</span> and node <span class=\"tex-span\">5</span>. Then it cannot propagate any more. So the values of the nodes are <span class=\"tex-span\">[1, 5, 1, - 2, - 1]</span>.</p><p>Then value <span class=\"tex-span\">2</span> is added to node <span class=\"tex-span\">1</span>. It propagates and value -<span class=\"tex-span\">2</span> is added to it's sons, node <span class=\"tex-span\">2</span> and node <span class=\"tex-span\">3</span>. From node <span class=\"tex-span\">2</span> it propagates again, adding value <span class=\"tex-span\">2</span> to it's sons, node <span class=\"tex-span\">4</span> and node <span class=\"tex-span\">5</span>. Node <span class=\"tex-span\">3</span> has no sons, so it cannot propagate from there. The values of the nodes are <span class=\"tex-span\">[3, 3, - 1, 0, 1]</span>.</p><p>You can see all the definitions about the tree at the following link: <span class=\"tex-font-style-tt\">http://en.wikipedia.org/wiki/Tree_(graph_theory)</span></p></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=E]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== statementText) {\r\n $problem.find(\".diff-notifier\").show();\r\n\r\n $problem.find(\".diff-notifier-close\").click(function() {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n $problem.find(\".diff-notifier\").hide();\r\n });\r\n\r\n $problem.find(\"a.view-changes\").click(function() {\r\n $.post(\"/data/diff\", {action: \"getDiff\", a: previousStatementText, b: statementText}, function (result) {\r\n if (result[\"success\"] === \"true\") {\r\n Codeforces.facebox(\".diff-popup\", \"//codeforces.org/s/73366\");\r\n $(\"#facebox .diff-popup\").html(result[\"diff\"]);\r\n }\r\n }, \"json\");\r\n });\r\n }\r\n } else {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n }\r\n });\r\n });\r\n </script>\r\n\r\n\r\n<script type=\"text/javascript\">\r\n $(document).ready(function () {\r\n window.changedTests = new Set();\r\n\r\n function endsWith(string, suffix) {\r\n return string.indexOf(suffix, string.length - suffix.length) !== -1;\r\n }\r\n\r\n const inputFileDiv = $(\"div.input-file\");\r\n const inputFile = inputFileDiv.text();\r\n const outputFileDiv = $(\"div.output-file\");\r\n const outputFile = outputFileDiv.text();\r\n\r\n\r\n if (!endsWith(inputFile, \"standard input\")\r\n && !endsWith(inputFile, \"standard input\")) {\r\n inputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n if (!endsWith(outputFile, \"standard output\")\r\n && !endsWith(outputFile, \"standard output\")) {\r\n outputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n const titleDiv = $(\"div.header div.title\");\r\n\r\n\r\n\r\n String.prototype.replaceAll = function (search, replace) {\r\n return this.split(search).join(replace);\r\n };\r\n\r\n $(\".sample-test .title\").each(function () {\r\n const preId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n const cpyId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n\r\n $(this).parent().find(\"pre\").attr(\"id\", preId);\r\n const $copy = $(\"<div title='Copy' data-clipboard-target='#\" + preId + \"' id='\" + cpyId + \"' class='input-output-copier'>Copy</div>\");\r\n $(this).append($copy);\r\n\r\n const clipboard = new Clipboard('#' + cpyId, {\r\n text: function (trigger) {\r\n const pre = document.querySelector('#' + preId);\r\n const lines = pre.querySelectorAll(\".test-example-line\");\r\n return Codeforces.filterClipboardText(pre.innerText, lines.length);\r\n }\r\n });\r\n\r\n const isInput = $(this).parent().hasClass(\"input\");\r\n\r\n clipboard.on('success', function (e) {\r\n if (isInput) {\r\n Codeforces.showMessage(\"The example input has been copied into the clipboard\");\r\n } else {\r\n Codeforces.showMessage(\"The example output has been copied into the clipboard\");\r\n }\r\n e.clearSelection();\r\n });\r\n });\r\n\r\n $(\".test-form-item input\").change(function () {\r\n addPendingSubmissionMessage($($(this).closest(\"form\")), \"You changed the answer, do not forget to submit it if you want to save the changes\");\r\n const index = $(this).closest(\".problemindexholder\").attr(\"problemindex\");\r\n let test = \"\";\r\n $(this).closest(\"form input\").each(function () {\r\n const test_ = $(this).attr(\"name\");\r\n if (test_ && test_.substring(0, 4) === \"test\") {\r\n test = test_;\r\n }\r\n });\r\n if (index.length > 0 && test.length > 0) {\r\n const indexTest = index + \"::\" + test;\r\n window.changedTests.add(indexTest);\r\n }\r\n });\r\n\r\n $(window).on('beforeunload', function () {\r\n if (window.changedTests.size > 0) {\r\n return 'Dialog text here';\r\n }\r\n });\r\n\r\n autosize($('.test-explanation textarea'));\r\n\r\n $(\".test-example-line\").hover(function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n let top = 1E20;\r\n let left = 1E20;\r\n let problem = $(this).closest(\".problemindexholder\");\r\n $(this).closest(\".input\").find(\".\" + clazz).css(\"background-color\", \"#FFFDE7\").each(function() {\r\n top = Math.min(top, $(this).offset().top);\r\n left = Math.min(left, $(this).offset().left);\r\n });\r\n let testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n if (testCaseMarker.length === 0) {\r\n const html = \"<div class=\\\"testCaseMarker testCaseMarker_\" + end + \" notice\\\"></div>\";\r\n problem.append($(html));\r\n testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n }\r\n if (testCaseMarker) {\r\n testCaseMarker.show()\r\n .offset({top, left: left - 20})\r\n .text(end);\r\n }\r\n }\r\n }\r\n });\r\n }, function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n $(\".\" + clazz).css(\"background-color\", \"\");\r\n $(this).closest(\".problemindexholder\").find(\".testCaseMarker_\" + end).hide();\r\n }\r\n }\r\n });\r\n });\r\n\r\n });\r\n</script>\r\n\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 05:38:09</span> (j3).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/73366/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/73366/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/73366/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/73366/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-73366.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'8122c42bbe9d00a1',t:'MTY5NjY0NjI4OS4zMjkwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"},"long_tags":{"kind":"string","value":"[\"Heaps, binary search trees, segment trees, hash tables, etc\", \"Dfs and similar\", \"Graphs\", \"Trees\"]"},"short_tags":{"kind":"string","value":"[\"data structures\", \"dfs and similar\", \"graphs\", \"trees\", \"*2000\"]"},"tutorial_link":{"kind":"string","value":"https://codeforces.com/blog/entry/10476"},"tutorial_page":{"kind":"string","value":"\r\n\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"4f4c31ed5807bbee2a02378cf0944c06\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"h1\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Codeforces Round #225 — Editorial - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n \n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Codeforces Round #225 — Editorial - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/81027/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/81027/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/81027/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/81027/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/81027/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/81027/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/81027/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/81027/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/81027/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/81027/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/81027/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/81027/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/81027/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/81027/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/573cedc6b04c15481941f418269f4057/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='4f4c31ed5807bbee2a02378cf0944c06'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/81027/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fblog%2Fentry%2F10476\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='4f4c31ed5807bbee2a02378cf0944c06'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Pay attention\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n <div style=\"text-align:center;border-bottom: 1px solid rgb(185, 185, 185);margin:0 -0.5em 0.5em -0.5em;padding: 0 1em 0.5em 1em;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 1, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:51:58</span><br/><a href=\"/contestRegistration/1876\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n <div style=\"text-align:center;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 2, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:51:58</span><br/><a href=\"/contestRegistration/1877\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n\r\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div>\r\n\r\n\n <div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\n\r\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='4f4c31ed5807bbee2a02378cf0944c06'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n </label>\r\n </div>\r\n <div style=\"padding: 0 1em 1em 1em;text-align:right;\">\r\n <input style=\"height:1.65em;padding:0 0.75em;\" type=\"submit\" value=\"Find\"/>\r\n </div>\r\n </form>\r\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".handleBox\").autocomplete(\"/data/handles\", {\r\n delay: 200,\r\n width: 200,\r\n selectFirst: false,\r\n matchContains: true,\r\n minChars: 3\r\n });\r\n $(\".handleForm\").attr(\"autocomplete\", \"off\").submit(function () {\r\n var link = \"/profile/userHandle\".replace(\r\n \"userHandle\", $(this).find(\".handleBox\").val()\r\n );\r\n window.location = link;\r\n return false;\r\n });\r\n });\n </script>\n\r\n\r\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Recent actions\n <div class=\"top-links\">\n </div>\n </div>\n <div class=\"recent-actions\">\r\n <ul>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/121073\">Meta Hacker Cup 2023 Round 1</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/.Danet\" title=\"Expert .Danet\" class=\"rated-user user-blue\">.Danet</a> →\r\n <a href=\"/blog/entry/121172\">[TLE on pretest1]</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\" class=\"rated-user user-red\">Pyqe</a> →\r\n <a href=\"/blog/entry/121025\">Codeforces Round #902 (Div. 1, Div. 2, based on COMPFEST 15 — Final Round)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pranshu_Pandya\" title=\"Specialist Pranshu_Pandya\" class=\"rated-user user-cyan\">Pranshu_Pandya</a> →\r\n <a href=\"/blog/entry/121171\">An Interesting Tree Problem</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/sszcdjr\" title=\"Master sszcdjr\" class=\"rated-user user-orange\">sszcdjr</a> →\r\n <a href=\"/blog/entry/119859\">Codeforces Round 896 (Div. 1, Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/119880\">It's Happening! Meta Hacker Cup 2023 Schedule</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/DaviddeGea1\" title=\"Expert DaviddeGea1\" class=\"rated-user user-blue\">DaviddeGea1</a> →\r\n <a href=\"/blog/entry/70917\">Number of ways of dividing an array into 2 parts such that sum of each part is > k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bekh\" title=\"Master Bekh\" class=\"rated-user user-orange\">Bekh</a> →\r\n <a href=\"/blog/entry/74245\">Questions and doubts regarding Aliens DP trick</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a> →\r\n <a href=\"/blog/entry/8192\">Codeforces Round #190 — Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/hocky\" title=\"Candidate Master hocky\" class=\"rated-user user-violet\">hocky</a> →\r\n <a href=\"/blog/entry/95323\">FBHC wuining uw Day? Incwease uw stacc size! (ㅅ´ ˘ `)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/liouzhou_101\" title=\"International Master liouzhou_101\" class=\"rated-user user-orange\">liouzhou_101</a> →\r\n <a href=\"/blog/entry/87598\">Editorial of Codeforces Round #700</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/yeon_gist\" title=\"Newbie yeon_gist\" class=\"rated-user user-gray\">yeon_gist</a> →\r\n <a href=\"/blog/entry/121170\">plusMinusPermutation computing error</a>\r\n <img alt=\"Text created or updated\" title=\"Text created or updated\" src=\"//codeforces.org/s/81027/images/icons/x-update-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/altforminuscontribution\" title=\"Newbie altforminuscontribution\" class=\"rated-user user-gray\">altforminuscontribution</a> →\r\n <a href=\"/blog/entry/121162\">My screen get unexpectedly big, what should I do</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/atcoder_official\" title=\"Unrated, atcoder_official\" class=\"rated-user user-black\">atcoder_official</a> →\r\n <a href=\"/blog/entry/121120\">We will hold UNIQUE VISION Programming Contest 2023 Autumn(AtCoder Beginner Contest 323)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/YouStill_DontKnowMeYet\" title=\"Candidate Master YouStill_DontKnowMeYet\" class=\"rated-user user-violet\">YouStill_DontKnowMeYet</a> →\r\n <a href=\"/blog/entry/117659\">[GYM] Al-Baath Collegiate Programming Contest 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/ankancool\" title=\"Expert ankancool\" class=\"rated-user user-blue\">ankancool</a> →\r\n <a href=\"/blog/entry/121136\">Invitation to AstroByte 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/GeZhiyuan\" title=\"Grandmaster GeZhiyuan\" class=\"rated-user user-red\">GeZhiyuan</a> →\r\n <a href=\"/blog/entry/120943\">Codeforces Round 901 (Div. 1, Div. 2) Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a> →\r\n <a href=\"/blog/entry/120772\">PSA: Increase your stack size before the Meta Hacker Cup, here's how</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/dino_merlin\" title=\"Expert dino_merlin\" class=\"rated-user user-blue\">dino_merlin</a> →\r\n <a href=\"/blog/entry/121145\">Intuitive approach for CEOI Kangaroo?</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/icecuber\" title=\"Grandmaster icecuber\" class=\"rated-user user-red\">icecuber</a> →\r\n <a href=\"/blog/entry/70018\">CSES DP section editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bn00b\" title=\"Newbie Bn00b\" class=\"rated-user user-gray\">Bn00b</a> →\r\n <a href=\"/blog/entry/98820\">[FEATURE REQUEST : ATCODER] TOPICS TAGS AND SORTING BY SOLVE COUNT</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a> →\r\n <a href=\"/blog/entry/121163\">AtCoder Regular Contest 166 Announcement</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/windva\" title=\"Grandmaster windva\" class=\"rated-user user-red\">windva</a> →\r\n <a href=\"/blog/entry/120644\">Codeforces Round 899 (Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Misa-Misa\" title=\"Expert Misa-Misa\" class=\"rated-user user-blue\">Misa-Misa</a> →\r\n <a href=\"/blog/entry/121157\">Someone please help me understand this.</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/shivam565\" title=\"Specialist shivam565\" class=\"rated-user user-cyan\">shivam565</a> →\r\n <a href=\"/blog/entry/108348\">Total number of subarrays with sum atmost k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n </ul>\r\n </div>\r\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/recent-actions\">Detailed →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n</div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li><a\r\n href=\"/profile/fchirica\">fchirica</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/fchirica\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/fchirica\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/fchirica\">Submissions</a></li>\r\n <li><a\r\n href=\"/groups/with/fchirica\">Groups</a></li>\r\n <li><a\r\n href=\"/contests/with/fchirica\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/fchirica\">Problemsetting</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/fchirica\" style=\"text-decoration:none;color:black !important;\">fchirica's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"10531\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/10476\"> <p>Codeforces Round #225 — Editorial</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/fchirica\" title=\"Candidate Master fchirica\" class=\"rated-user user-violet\">fchirica</a>,\r\n <span class=\"format-humantime\" title=\"Jan/20/2014 22:18\">10 years ago</span>,\r\n \r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><h1><a href=\"/contest/384/problem/A\" title=\"Codeforces Round 225 (Div. 2)\">384A - Coder</a></h1><p>Usually, when you don’t have any idea how to approach a problem, a good try is to take some small examples.</p><p>So let’s see how it looks for N = 1, 2, 3, 4 and 5. With C I noted the coder and with * I noted an empty cell.</p><p><img alt=\" \" src=\"/predownloaded/8f/89/8f899efd227362957f283123a7927c7c8a300667.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>By now you should note that answer is N ^ 2 / 2 when N is even and (N ^ 2 + 1) / 2 when N is odd. Good. Generally, after you find a possible solution by taking examples, you need to prove it, then you can code it.</p><p>In order to proof it, one needs to do following steps:</p><p>1/ prove you can always build a solution having N ^ 2 / 2 (or (N ^ 2 + 1) / 2) pieces.</p><p>2/ prove that N ^ 2 / 2 (or (N ^ 2 + 1) / 2) is maximal number – no other bigger solution can be obtained.</p><p>For proof 1/ imagine you do coloring like in a chess table.</p><p><img alt=\" \" src=\"/predownloaded/50/12/50120d92bd0cea3d6a434d09ab4754ea20342351.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>The key observation is that by placing all coders on black squares of table, no two coders will attack. Why? Because a piece placed at a black square can attack only a piece placed at a white square. Again, why? Suppose chess table is 1-based. Then, a square (i, j) is black if and only if i + j is even. A piece placed at (i, j) can attack (i + 1, j), (i – 1, j) (i, j + 1) or (i, j – 1). The sum of those cells is i + j + 1 or i + j – 1. But since i + j is even, i + j + 1 and i + j – 1 are odd, hence white cells.</p><p>Depending on parity of N, number of black cells is either N ^ 2 / 2 or (N ^ 2 + 1) / 2. For N even, one can observe that there are equal amount of black and white cells. Total number of cells is N ^ 2, so number of black cells is N ^ 2 / 2. For N odd, number of black cells is number of white cells + 1. We can imaginary add a white cell to the board. Now, number of black cells will be also equal to number of white cells, so answer is (N ^ 2 + 1) / 2.</p><p>2/ Two coders attack each other if they are placed at two adjacent cells, one black and other one white. One needs to prove that adding more than number from 1/ will cause this to happen. If you place a coder at a white cell, you won’t be able to place at least one coder at a black cell, so in best case you don’t win anything by doing this. Hence, it’s optimally to place all coders on same color cells. Since cells colored in black are always more or equal to white ones, it’s always optimally to choose black color. But number from 1/ is the number of cells having black color. Adding one more piece will force you to add it to a white color cell. Now, you’ll have a piece placed at a black colored cell and one placed at an adjacent white colored cell, so two coders will attack. Hence, we can’t place more than number from 1/ pieces.</p><p>Code: <a href=\"http://pastie.org/8651801\">http://pastie.org/8651801</a></p><h1><a href=\"/contest/384/problem/B\" title=\"Codeforces Round 225 (Div. 2)\">384B - Multitasking</a></h1><p>Let’s start by saying when array A[] is sorted:</p><p>1/ is sorted in ascending order when i < j and A[i] <= A[j]. It is NOT sorted when i < j and A[i] > A[j].</p><p>2/ is sorted in descending order when i > j and A[i] <= A[j]. It is NOT sorted when i > j and A[i] > A[j].</p><p>Iahub can choose 2 indices i, j and swap values when A[i] > A[j]. If A[i] <= A[j], he’ll ignore operation. Hence, if he wants to sort all arrays in ascending order, he chooses indices i, j when i < j and perform operation. Otherwise, in all his operations he uses indices i, j such as i > j. A “good” operation is when choosing indices i < j for ascending order sorting and i > j for descending order sorting. By doing only good operations, after an array is sorted, it will stay sorted forever (for a sorted array, all good operations will be ignored).</p><p>From here we get our first idea: use any sorting algorithm you know and sort each array individually. When print swaps done by sorting algorithm chosen, print them as good operations. However, sorting each array individually can cause exceeding M * (M — 1) / 2 operations limit. Another possible solution would be, after you did an operation to an array, to update the operation to all arrays (you printed it, so it counts to M * (M — 1) / 2 operations limit; making it to all arrays will help sometimes and in worst case it won’t change anything). However, you need to code it very careful in order to make this algorithm pass the time limit. Doing this in a contest is not the best idea, especially when implementation could be complicated and you have no guarantee it will pass time limit.</p><p>So what else can we do? We can think out of box. Instead of sorting specific N arrays, you can sort all possible arrays of length M. Find a sequence of good operations such as, anyhow I’d choose an array of size M, it will get sorted ascending / descending.</p><p>I’ll show firstly how to do for ascending sorting. At position 1 it needs to be minimal element. Can we bring minimal element there using good operations? Yes. Just do “1 2” “1 3” “1 4” ... “1 M”. It basically compares element from position 1 to any other element from array. When other element has smaller value, swap is done. After comparing with all M elements, minimal value will be at position 1. By now on I’ll ignore position 1 and move to position 2. Suppose array starts from position 2. It also needs minimal value from array, except value from position 1 (which is no longer in array). Hence doing “2 3” “2 4” “2 5” ... “2 M” is enough, by similar reasons. For a position i, I need minimal value from array, except positions 1, 2, ..., i – 1. I simply do “i i+1” “i i+2” ... “i M-1” “i M”. By arriving at position i, array will be sorted ascending. The algorithm is simply:</p><p>for (int i = 1; i < M; ++i)</p><p>for (int j = i + 1; j <= M; ++j)</p><p>cout << i << “ “ << j << “\\n”;</p><p>This algorithm does exactly M * (M — 1) / 2 moves.</p><p>Can you find out how to sort array in descending order? Try to think yourself, then if you don’t get it read next. At first position of a descending array it needs to be maximal value. Similarly to ascending order, we can do “2 1” “3 1” “4 1” ... “M 1”. When I’m at a position i and I compare its value to value from position 1, doing operation “i 1” checks if A[i] > A[1]. If so, it swaps A[i] and A[1], so position 1 will contain now the maximum value so far. Similarly to logic from ascending order, when I’m at position i, I need maximum value from array except positions 1, 2, ..., i – 1, so I do “i+1 i” “i+2 i” ... “M i”. Algorithm is:</p><p>for (int i = 1; i < M; ++i)</p><p>for (int j = i + 1; j <= M; ++j)</p><p>cout << j << “ “ << i << “\\n”;</p><p>Obviously, this does as well M * (M — 1) / 2 operations worst case. All algorithm is about 10 lines of code, much better than other solution, which requires two manually sorts and also has a chance to exceed TL.</p><p>Code: <a href=\"http://pastie.org/8651809\">http://pastie.org/8651809</a></p><h1><a href=\"/contest/384/problem/C\" title=\"Codeforces Round 225 (Div. 2)\">384C - Milking cows</a></h1><p>A good strategy to approach this problem is to think how optimal ordering should look like. For this, let’s calculate for each 2 different cows i and j if cow i needs to be milked before or after cow j. As we’ll show, having this information will be enough to build optimal ordering. It is enough to consider only cases when i < j, case when i > j is exactly the opposite of case i < j. For formality, I’ll call the optimal ordering permutation and lost milk the cost of permutation.</p><p>So, for an optimal permutation P let’s take 2 numbers i < j and see in which cases i should appear before j in permutation (i is before j if P[pos1] = i, P[pos2] = j and pos1 < pos2; otherwise we’ll call i is after j). We have 4 possible cases:</p><p>1/ A[i] = 0 and A[j] = 0</p><p>If we put i before j, no additional cost will be added. Since j is in right of i and i only adds cost when it finds elements in left of i, j won’t be affected when processing i. When processing j, i will be already deleted so it won’t affect the cost either. Hence, we can put i before j and no cost will be added.</p><p>2/ A[i] = 0 and A[j] = 1</p><p>Here, i and j can appear in arbitrary order in permutation (i can be before or after j). No matter how we choose them, they won’t affect each other and cost will remain the same.</p><p>3/ A[i] = 1 and A[j] = 0</p><p>As well, here i and j can appear in arbitrary order. If we choose i first, j will be in right of it, so cost of permutation will increase by one. If we choose j first, i will be in left of it so cost of permutation will increase as well. No matter what we do, in this case cost of permutation increases by 1.</p><p>4/ A[i] = 1 and A[j] = 1</p><p>Here, i needs to be after j. This adds 0 cost. Taking i before j will add 1 cost to permutation (since j is in right of i).</p><p>Those 4 cases show us how a minimal cost permutation should look. In a permutation like this, only case 3/ contributes to final cost, so we need to count number of indices i, j such as i < j and A[i] = 1 and A[j] = 0 (*). If we show a permutation following all rules exists, task reduces to (*).</p><p>By cases 2/ and 3/ it follows that in an optimal permutation, it only matters order of elements having same value in A[]. We can put firstly all elements having value 0 in A[], then all elements having value 1 in A[]. We can order elements having value 0 by case 1/ and elements having value 1 by case 4/. More exactly, suppose i1 < i2 < ... < im and (A[i1] = A[i2] = ... = A[im] = 0) and j1 > j2 > ... > jn (A[j1] = A[j2] = ... = A[jn] = 1). Then, a permutation following all rules is {i1, i2, ..., im, j1, j2, ..., jn}. This permutation can always be built.</p><p>Hence, task reduces to (*): count number of indices i, j such as i < j and A[i] = 1 and A[j] = 0. We can achieve easily an O(N) algorithm to do this. Let’s build an array cnt[j] = number of 0s in range {j, j + 1, ..., N} from array A. We can easily implement it by going backwards from N to 1. The result is sum of cnt[i], when A[i] = 1.</p><p>Code: <a href=\"http://pastie.org/8651813\">http://pastie.org/8651813</a></p><h1><a href=\"/contest/384/problem/D\" title=\"Codeforces Round 225 (Div. 2)\">384D - Volcanoes</a></h1><p>Our first observation is that if there is a path from (1, 1) to (N, N), then the length of path is 2 * N – 2. Since all paths have length 2 * N – 2, it follows that if there is at least one path, the answer is 2 * N – 2 and if there isn’t, the answer is -1. How to prove it? Every path from (1, 1) to (N, N) has exactly N – 1 down directions and exactly N – 1 right directions. So, total length for each path is N – 1 + N – 1 = 2 * N – 2. </p><p>So we reduced our problem to determine if there is at least one path from (1, 1) to (N, N). This is the challenging part of this task, considering that N <= 10 ^ 9. How would you do it for a decently small N, let’s say N <= 10^3 . One possible approach would be, for each row, keep a set of reachable columns. We could easily solve this one by doing this: if (i, j) denotes element from ith row and jth column, then (i, j) is (is not) reachable if:</p><p>if (i, j) contains a volcano, then (i, j) is not reachable. Otherwise, if at least one of (i – 1, j) and (i, j – 1) is reachable, then (i, j) is reachable. Otherwise, (i, j) is not reachable.</p><p>What’s the main problem of this approach? It needs to keep track of 10^9 lines and in worst case, each of those lines can have 10^9 reachable elements. So, worst case we need 10^9 * 10^9 = 10^18 operations and memory.</p><p>Can we optimize it? We can note for beginning that we don’t need to keep track of 10^9 lines, only m lines are really necessarily. We need only lines containing at least one obstacle (in worst case when each line contains only one obstacle, we need m lines). How to solve it this way? Suppose line number x contains some obstacles and lines x + 1, x + 2, x + 3 do not contain any obstacle. Suppose we calculated set S = {y | cell (x, y) is reachable}. How would look S1, S2, S3 corresponding to lines x + 1, x + 2, x + 3? For S1, we can reach cell (x + 1, ymin), where ymin is minimal value from set S. Then, we can also reach {ymin + 1, ymin + 2, ..., N}, by moving right from (x + 1, ymin). So S1 = {ymin, ymin + 1, ..., N}. How do S2 and S3 look? It’s easy to see that they’ll be as well {ymin, ymin + 1, ..., N}. So we get following optimization: suppose set of lines containing at least one obstacle is {L1, L2, ..., Lk}. We need to run algorithm only for lines L1, L1 + 1, L2, L2 + 1, L3, L3 + 1, ..., Lk, Lk + 1.</p><p>It looks like we didn’t make anything with this optimization. Even if we calculate for m lines, each line can still have 10^9 reachable positions. So worst case we perform 10^14 operations. We need something better for managing information from a line. You can note that for a given line y, there are a lot of positions having consecutive values. There are a lot of positions (x, y) and (x, y + 1) both reachable. This should give us following idea: what if instead of keeping reachable positions, we keep reachable ranges? That is, for each line x we keep a set of ranges S = {(a, b) | all cells (x, k) with a <= k <= b are reachable}. </p><p>How many ranges can it be for a line? If the line contains m obstacles, there are m + 1 ranges. Suppose for line x all cells are reachable, but for line x + 1 cells (x + 1, 3) (x + 1, 5) (x + 1, N – 1) are blocked. Then, the ranges of reachable cells are [1, 2] [4, 4], [6, N – 2] and [N, N]. By now, we get worst case m lines and worst case each line having m elements, so in worst case we’d have to handle m * m = 10 ^ 10 events. This may still look too much, but happily this bound is over estimated. If a line has o obstacles, there can be at most o + 1 ranges. If lines L1, L2, ..., Lk have {o1, o2, ..., ok} obstacles, there’ll be at most o1 + o2 + ... + ok + k ranges. But o1 + o2 + ... + ok = m and also k is at most m (proved above why we’re interested in at most m lines), so in worst case we get m + m = 2 * m ranges. Yaay, finally a decent number of states for this problem :)</p><p>So, we iterate each line we’re interested in. Let’s find set of ranges for this line, thinking that all cells from line above are reachable. This is easy to do. After we get our ranges like all cells from above can be visited, let’s think how having obstacles above can influence current ranges. After adding ranges from above, current ranges can’t increase (obviously), they can only decrease, remain the same or some of them can become empty. So, let’s take each range [a, b] from current line and see how it will transform after adding ranges from previous line. </p><p>Given range [a, b], it can transform only in [a’ , b] with a’ >= a. If a’ > b, then obviously range is empty. Why second number of range keeps constant? Let a’ smallest reachable column from current line which is in range [a, b]. It’s enough to check a’ >= a, as if a’ > b, range will be empty. It’s obviously why we need to keep a’ smallest value possible >= a: we’re interested to keep range as big as possible and as less as we cut from left, as big it is. Once we’ve found a’ in range [a, b] (or a’ > b if range is empty) all cells {a’ + 1, a’ + 2, ..., b} are reachable as well by going right from a’, so if interval is not empty, then second number defining it remains b.</p><p>Next question is how to find a’ fast enough. In order a point a’ to be reachable on current range, it also needs to exist a range on previous line containing it. If the range from previous line is [pa, pb] then a’ needs to follow 3 conditions:</p><p>a’ minimal such as</p><p>pa <= a’ <= pb</p><p>a’ >= a</p><p>What if instead of finding a’ we find [pa, pb]? Then a’ is max(pa, a). In order a’ to be as small as possible, since a is constant, pa needs to be as small as possible. So we reduced it to:</p><p>pa minimal pb >= a’ >= a <=> pb >= a</p><p>Intervals from previous line are disjoint, no 2 intervals cross each other. It means that if pb is minimal, than pa is minimal too (if we increase pb, then pa will increase too, so it won’t be minimal). Hence, you need to find an interval [pa, pb] such as pb is minimal and pb >= a. Then, a’ is max(a, pa). This is easy to do if we sort all intervals from previous line increasing by second value (pb), then we binary search for value a. </p><p>Finally, after running algorithm for all lines, last range from last line has second number N (assuming ranges are sorted increasing by second value), then there exist a path, otherwise there does not exist. This algorithm should run O(m * logm) worst case, good enough to pass. </p><p>Code: <a href=\"http://pastie.org/8651817\">http://pastie.org/8651817</a></p><h1><a href=\"/contest/384/problem/E\" title=\"Codeforces Round 225 (Div. 2)\">384E - Propagating tree</a></h1><p>This is kind of task that needs to be break into smaller subproblems that you can solve independently, then put them together and get solution.</p><p>Let’s define level of a node the number of edges in the path from root to the node. Root (node 1) is at level 0, sons of root are at level 1, sons of sons of root are at level 2 and so on.</p><p>Now suppose you want to do an operation of type 1 to a node x. What nodes from subtree of x will be added +val (a positive value)? Obviously, x will be first, being located at level L. Sons of x, located at level L + 1 will be added –val. Sons of sons, located at level L + 2, will be added value +val again. So, nodes from subtree of x located at levels L, L + 2, L + 4, ... will be added a +val, and nodes located at levels L + 1, L + 3, L + 5 will be added a –val. Let’s take those values of L modulo 2. All nodes having remainder L modulo 2 will be added a +val, and nodes having reminder (L + 1) modulo 2 will be added –val. In other words, for a fixed x, at a level L, let y a node from subtree of x, at level L2. If L and L2 have same parity, +val will be added to y. Otherwise, -val will be added to y.</p><p>From here we have the idea to split nodes of tree in 2 sets – those being located at even level and those being located at odd level. What still makes the problem hard to solve? The fact that we have a tree. If nodes from a subtree would be a contiguous sequence instead of some nodes from a tree, problem would be simpler: the problem would reduce to add / subtract values to all elements of a subarray and query about a current value of an element of array. So, how can we transform tree to an array, such as for a node x, all nodes from subtree of x to be a subarray of array?</p><p>The answer is yes. We can do this by properties of DFS search. Before reading on, make sure that you know what is discovery time and finish time in a DFS search. Let’s build 3 arrays now – discover[], representing nodes in order of their discover times (a node is as before in discover as it has a small discover time), begin[] = for a node, in which time it was discovered and end[] = what’s last time of a discovered node before this node finishes. For a subtree of x, all nodes in the subtree are nodes in discover from position begin[x] to end[x].</p><p>Example: suppose you have tree 1-5; 1-6; 6-7; 6-4; 4-2; 4-3</p><p>Discover is {1, 5, 6, 7, 4, 2, 3}.</p><p>begin is {1, 6, 7, 5, 2, 3, 4}.</p><p>end is {7, 6, 7, 7, 2, 7, 4}.</p><p>What’s subtree of node 6? elements of discover from position begin[6] to end[6]. In this case, from 3 to 7, so elements {6, 7, 4, 2, 3}. You can see it’s correct and take more examples if you want :)</p><p>Now, we reduced problem to: you’re given an array A. you can perform 2 operations:</p><p>1/ increase all elements from a range [x, y] to a value val (val can be negative, to treat subtractions)</p><p>2/ what’s current value of an element from position pos.</p><p>Those who solved “Iahub and Xors” from my last round, CF 198, should probably say they saw something similar before. If you didn’t solve problem before, I encourage you to do it after you solve this one, it uses a similar idea to what will follow now. Also, if you don’t know Fenwick trees, please read them before moving on. An alternative would be for this task using segment trees with lazy update, but I see this one more complicated than needed.</p><p>I’ll use now a not so common approach when dealing with data structures. Instead of keeping in a node the result, like you usually do, I’ll keep just an auxiliary information. So what algorithm proposed does:</p><p>Let A an array, initially with all elements 0.</p><p>When you need to update range [x, y] with value val, you simply do A[x] += val and A[y + 1] -= val.</p><p>When you need to answer a query about position pos, you output A[1] + A[2] + ... + A[pos].</p><p>Implemented brute force, you get O(1) per update and O(N) per query. However, these both are operations supported by a Fenwick tree, so you can get O(logN) per operation.</p><p>It may not be very clear why this algorithm works. Let’s take a closer look: an update needs to add value val only to range [x, y]. When you query a position pos, let’s see if algorithm handles it correctly:</p><p>1/ pos < x. In this case, result must not be affected by my update. Since pos < x and I only updated 2 values with indices >= x, when doing A[1] + A[2] + ... + A[pos] it won’t matter at all I did that update – at least not for this query.</p><p>2/ x <= pos <= y. Here, for a pos, I need to add value val only once. We add it only at A[x] – in this way it will be counted once, and it will be considered for each elements from range [x, y] (since an element at position p from range [x, y] has p >= x, in A[1] + A[2] + ... + A[p] I’ll have to consider A[x]).</p><p>3/ pos > y. Here I don’t have to consider the query. But it would be considered when processing A[x]. But if I add to A[y + 1] value –val I’ll just cancel the value previously added.</p><p>Code (actually we use just one Fenwick tree instead of 2, can you think why it works? :) ) : <a href=\"http://pastie.org/8651824\">http://pastie.org/8651824</a></p><h1><a href=\"/contest/383/problem/D\" title=\"Codeforces Round 225 (Div. 1)\">383D - Antimatter</a></h1><h2>Author's solution</h2><p>The problem is: given an array, iterate all possible subarrays (all possible elements such as their indexes are consecutive). Now, for a fixed subarray we need to know in how many ways we can color its elements in black and white, such as sum of black elements is equal to sum of white elements. The result is sum of this number, for each subarray.</p><p>Let’s solve an easier problem first. This won’t immediately solve the harder version, but it will be useful later. Suppose you’ve fixed a subarray. In how many ways can you color it with black and white? Suppose subarray has N elements and sum of them is M. Also, suppose for a coloring, sum of blacks is sB and sum of whites is sW. For coloring to be valid, sB = sW. But we also know that sB + sW = M (because each element is colored by exactly one color). We get that 2 * sB = M, so sB = M / 2. The problem is now: in how many ways can we color elements in black such as sum of blacks is M / 2 (after we fix a black coloring, we color with white non colored elements; sum of white colored elements is also M / 2). This is a well known problem: Knapsack problem. Let ways[i][j] = in how many ways one can obtain sum j from first i elements. When adding (i + 1) object, after ways[i] is calculated, for a fixed sum j we can do 2 things: add (i + 1) object to sum j or skip it. Depending of what we chosen, we add value ways[i][j] to ways[i + 1][j + value[i + 1]] or to ways[i + 1][j]. The result is in ways[N][M / 2]. This works in O(N * M) time.</p><p>An immediate solution can be obtained now: take all subarrays and apply above approach. This leads to an O(N ^ 2 * M ^ 2) solution, which is too much. One can reduce complexity to O(N ^ 2* M) by noting that processing subarray [i, j] can be done with already calculated values for subarray [i, j – 1]. Hence, instead of adding N elements, it’s enough to add 1 element to already calculated values (element from position j). Sadly, O(N ^ 2 * M) is still too slow, so we need to find something better. The solution presented below will look forced if you didn’t solve some problems with this technique before. It’s hard to come with an approach without practicing this kind of tasks. But don’t worry, as much as you practice them, as easily you’ll solve those problems.</p><p>We’ll solve task by divide and conquer. Complexity of this solution is O(N * M * logN). Let f(left, right) a function that counts number of colorings for each subarray [i, j], such as subarray [i, j] is included in subarray [left, right] (left <= i <= j <= right). Answer is in f(1, N). The trick is to define a value med = (left + right) / 2 (very frequent trick in divide and conquer problems, called usually a median). We can next classify [i, j] subarrays in 3 types:</p><p>1/ i <= med j <= med</p><p>2/ i > med j > med</p><p>3/ i <= med j > med</p><p>We can solve 1/ and 2/ by calling f(left, med) and f(med + 1, right). The remained problem is when i <= med and j > med. If we solve 3/ in O((right – left) * M) time, this will be enough to overall achieve O(N * M * logN) (for this moment trust me, you’ll see later why it’s so :) ).</p><p>Let’s denote by i1 last i1 elements from subarray [left, med]. Also, let’s note by i2 first i2 elements from subarray [med + 1, right]. For example, let left = 1 and right = 5, with array {1, 2, 3, 4, 5}. med is 3 and for i1 = 2 and i2 = 1, “left” subarray is {2, 3} and “right” subarray is {4}. By iterating i1 from 1 to med – left + 1 and i2 from 1 to right – med and then unite subarrays i1 and i2, we obtain all subarrays described in 3/ . Let’s denote by j1 sum of a possible black coloring of i1. Similarly, j2 is sum of a possible black coloring of i2.</p><p>Suppose we fixed i1, i2, j1 and j2. When it’s the coloring valid? Let S sum of united subarrays i1 and i2 (S = value[med – i1 + 1] + value[med – i1 + 2] + ... + value[med] + value[med + 1] + ... + value[med + i2 – 1] + value[med + i2]). Now it’s time to use what I explained at the beginning of solution. The coloring is good only when j1 + j2 = S / 2. We can rewrite the relation as 2 * (j1 + j2) = sum_of_elements_from_i1 + sum_of_elements_from_i2. We can rewrite it even more:</p><p>2 * j1 + 2 * j2 — sum_of_elements_from_i1 — sum_of_elements_from_i2 = 0</p><p>2 * j1 – sum_of_elements_from_i1 = sum_of_elements_from_i2 – 2 * j2 = combination_value</p><p>This relation is the key of solving problem. You can see now that relation is independent in “left” and “right” side. We calculate left[i1][j1] and right[i2][j2] = in how many ways can I obtain sum of blacks j1 (j2) from first i1 (i2) from left (right) side. Let’s calculate also count[value] = in how many ways can I obtain combination_value equal to value in the right side. For some fixed (i2, j2) I add to count[sum_of_elements_from_i2 – 2 * j2] value right[i2][j2]. In this way count[] is calculated correctly and completely. Now, let’s fix a sum (i1, j1) in the left side. We’re interested how many good colorings are such as there exist a coloring of j1 in i1 elements (the endpoint of “left” is fixed to be i1 and I need to calculate endpoints i2 for right, then to make colorings of i2). A coloring is good if combination_value of (i1, j1) and (i2, j2) is equal. Hence, I need to know in how many ways I can color i1 elements to obtain sum j1 and also I need to know in how many ways I can color elements from right to obtain same combination_value as it’s in the left. It’s not hard to see that answer for a fixed (i1, j1) is left[i1][j1] * count[2 * j1 – sum_of_elements_from_i1]. This takes O((right – left) * M) time.</p><p>The only thing remained in the problem is to see why complexity is O(N * M * logN). We can assume N is a power of 2 (it not, let’s round N to smallest power of 2 bigger than N; complexity for N is at least as good as complexity for this number). Draw a binary complete tree with N nodes. Each node corresponds to an appeal of f(). For a level, exactly O(N * M) operations are performed. To see why:</p><p>For level 1, there’ll be 1 node performing N * M operations.</p><p>For level 2, there’ll be 2 nodes performing (N / 2) * M operations. Summing up we get O(N * M).</p><p>For level 3, there’ll be 4 nodes performing (N / 4) * M operations. Summing up we get O(N *M) as well.</p><p>and so on.</p><p>So for each level we perform O(N * M) operations. A binary complete tree has maximum O(logN) levels, so overall complexity is O(N * M * logN).</p><p>Code: <a href=\"http://pastie.org/8651826\">http://pastie.org/8651826</a></p><h2>Solution fount by contestants</h2><p>This was totally unexpected to us :) Good job finding it, you guys are really smart. </p><p>We observe that x units of antimatter is the same thing as -x units of matter. Then we can consider that an element produces either x or -x units of matter. A valid substring is one that can have the sum of the elements 0. The problem is reduced to finding how many different substrings can we have with sum 0 (a substring is different than another one if it has different indices, or if at least one element produces matter in one and antimatter in the other).</p><p>This problem can be solved with dynamic programming. We will hold D[i][j] = the number of substrings that end in element i, and have sum j. It's easy to see that D[i + 1][j] = D[i][j — x] + D[i][j + x], where x is the value of the current element (we can put either -x or x). After we finish computing all the values for current i, we add to the solution D[i][0] (how many valid substrings do we have). After that, we add 1 to D[i][0], meaning that there is an empty substring starting at position i (however, we don't need to add it to the answer).</p><p>For a code, check passing submissions during contest. </p><h2><a href=\"/contest/383/problem/E\" title=\"Codeforces Round 225 (Div. 1)\">383E - Vowels</a></h2><h2>Author's solution</h2><p>Let's iterate over all possible vowel sets. For a given set {x1, x2, ..., xk} we're interested in number of correct words from dictionary. After a precalculation, we can do it in O(k).</p><p>Suppose our current vowel set is {x1, x2, ..., xk}. How many words are covered by the current vowels? By definition, we say a word is covered by a set of vowels if at least one of 3 letters of word is in vowel set. We can calculate this number using principle of inclusion and exclusion. We’ll denote by |v1, v2, v3, ...| = number of words containing ALL of vowels v1, v2, v3, ... . Using principle of inclusion and exclusion we get:</p><p>number_of_words_covered = |x1| + |x2| + .. + |xk| — |x1, x2| — |x1, x3| — .... + |x1, x2, x3| + |x1, x2, x4| + .... + |xk-2, xk-1, xk|. This formula is simply a reformulation of principle of inclusion and exclusion. You can easily observe that |v1, v2, ..., vk| makes sense only when k is at most 3, as no word from input can contain 4 or more letters (and hence can’t contain 4 or more vowels). </p><p>Example:</p><p>Suppose words are abc, abd and bcd. </p><p>|a| = 2 (first 2 words both contain character a).</p><p>|a, b| = 2 (as well, first 2 words contain characters a and b).</p><p>|b| = 3 (all 3 words contain character b).</p><p>|a, b, d| = 1 (only second word contains all 3 characters).</p><p>Also, note how principle of inclusion and exclusion works. number of words covered for vowels {a, b} is |a| + |b| — |a, b| = 2 + 3 – 2. Indeed, answer is 3.</p><p>We divide our problem in 3 subproblems. First one, for a vowel set, compute sum of |a|, where a is a letter from subset. Second, compute sum of |a, b|, where both a and b are letters from set. Third, compute sum of |a, b, c|, where a, b, c are letters from set. As stated, the answer is number_from_1st_step + number_from_3rd_step – number_from_2nd_step. If you followed me, you’ll see that we want to compute results for each subproblem in O(queryLetters).</p><p>First subproblem can be solved trivially in O(queryLetters). Let array single[], with following meaning: single[c] is how many words contain character c. It can be trivially precomputed in O(24 * N). Note that if a word contains twice/third times a character c, it needs to be counted only one (e.g. word aba will add only 1 to single[a]). For compute result of this subproblem for a given set of vowels, I’ll take all letters from set. If letter belongs to set, I add to result single[letter]. This step can be also be solved in O(1), but there’s no need, since other subproblems allow only an O(queryLetters) solution. </p><p>For second and third subproblems it’s a little more difficult. I’ll present here how to solve second subproblem and some hints for third one (if you understand second, with hints you should be able to solve third one by your own).</p><p>Similarly to first step, I’ll define a matrix double[c1][c2] = how many words contain both characters c1 and c2. A trivially solution would be, for a given vowel set, take all combinations of letters c1 and c2 that belong to set and add to result value double[c1][c2]. However, this solves each query in O(queryLetters^2), which is too slow.</p><p>Note, if we’d have 12 letters, instead of 24, this approach would be fast enough. From here it comes a pretty classical idea in exponential optimization: meet in the middle attack. We split those 24 letters in 2 groups: first 12 letters and last 12 letters. The answer for a subset is sum of double[c1][c2] (when c1 and c2 belong to current vowel set) when</p><p>1/ c1 and c2 belong to first 12 letters</p><p>2/ c1 and c2 belong to last 12 letters</p><p>3/ c1 belongs to first 12 letters and c2 belongs to last 12 letters</p><p>1/ and 2/ can be immediately precalculated as stated above, in O(2 ^ 12 * 12 ^ 2). We’ll remember results for each half using bitmasks arrays. Let Half1[mask] = sum over double[c1][c2], when c1 and c2 are in first 12 letters and correspond to 1 bits of mask. Half2[mask] is defined similarly, but for last 12 letters (e.g. subset {a, c, d} corresponds to bitmask 2^0 + 2^2 + 2^3 = 13 in first half and subset {m, n, p} corresponds to bitmask 2^0 + 2^1 + 2^3 = 11 for second half). Now, for a given subset, one can answer first 2 parts in O(queryCount) worst case (read input for a query and convert it to bitmasks). </p><p>How to answer 3? With another precalculation, of course. We know c1 letter needs to be in first 12 letters and c2 needs to be in last 12 letters. The precalculation we do here is: mixed_half[mask][i] = sum over |c1, c2|, when c1 belongs to first half and is a 1 bit of mask and c2 is i-th character of second half. Hence, for a query, we can fix character from second half (c2, by iteration of query letters from second half) and know sums of |c1, c2| between it and all available characters from first half after we do this precalculation. Also, precalculation is done trivially in O(2 ^ 12 * 12^2): fix mask, fix i and then iterate over 1 bits from mask and add double[c1][c2]. </p><p>Third subproblem is left, but it can be done similarly to second one. Instead of double[c1][c2], we’ll have triple[c1][c2][c3] = how many words contain all 3 characters c1, c2 and c3? We also do meet in the middle here, divide those 24 letters into 2 sets of 12 letters. We have 4 cases:</p><p>1/ c1, c2, c3 belong to first half</p><p>2/ c1, c2, c3 belong to second half</p><p>3/ c1, c2 belong to first half and c3 to second half</p><p>4/ c1 belongs to first half and c2, c3 to second half</p><p>1/ and 2/ are done brute force, like in second subproblem (the only difference is we choose 3 characters instead of 2, having complexity O(2 ^ 12 * 12 ^ 3)). For 3/ and 4/ we also precompute 2 matrixes: </p><p>mixed_two_one[mask][i] = c1 and c2 belong to mask from first half and c3 is i-th character from second half </p><p>and </p><p>mixed_one_two[mask][i] = c1 is i-th character from first half and c2, c3 belong to mask from second half. </p><p>Those can also be calculated in O(2 ^ 12 * 12^3).</p><p>So precalculation part is O(2 ^ 12 * 12 ^ 3) = 7077888 operations.</p><p>For calculate answering queries complexity, take all numbers from 0 to 2^24 — 1 and sum their bit count. This is a well known problem, the sum is 0 * C(24, 0) + 1 * C(24, 1) + ... + 24 * C(24, 24) = 201326592. In total we get 208404480 operations. C++ source makes them in 2 seconds. </p><p>Code: <a href=\"http://pastie.org/8651829\">http://pastie.org/8651829</a></p><h2>Solution fount by contestants</h2><p>Like in D1 D task, official solution was over complicated. This solution is more simple to understand, code and it's more elegant. If someone wants to complicate his life, (s)he can code also official solution :)</p><p>Let's start by assigning a bitmask to each word in following way: ith bit is 1 if and only if letter ('a' + i) appears in the current word. For example, for word acd, its bitmask is 2^0 + 2^2 + 2 ^ 3 = 13 and for word aab its bitmask is 2^0 + 2^1 = 3. After reading the words from dictionary, we store a matrix cnt[mask] = how many words from dictionary correspond to mask?</p><p>We iterate bitmasks from 0 to 2^24 — 1, this time corresponding to each possible question of Iahubina. Let's focus on a bitmask X. We need to get sum of cnt[mask], when mask and X share at least one common bit having value 1 (formally (X AND mask) > 0). In order to do this, we need a reduction which may be not so obvious. </p><p>What if instead of counting all words containing at least one of vowels {w1, w2, ..., wk} we count all words which don't contain ANY of vowels {w1, w2, ..., wk}? Suppose this number is ret. Then, all words containing at least one of vowels is N — ret. From all words, we erase those words which do not contain any vowels from set {w1, w2, ..., wk} (and which obviously are wrong words). Obviously, it's left only words containing at least one vowel, so good words. Now, for a word not to contain any of vowels {w1, w2, ..., wk} it needs to contains ONLY vowels from set {"a", "b", "c", ..., "x"} \\ {w1, w2, ..., wk} (set of allowed letters from which we erased vowels w1, w2, ..., wk}. </p><p>And this is reduction we needed. For a bitmask X we need to calculate sum of cnt[mask], where mask is a subset of X (we can set some bits from X from 1 to 0 in order to obtain mask). For a mask, let's keep this sum in res[mask]. We can calculate res array using divide and conquer.</p><p>Let's make a function solve(left, right), which completes array res in the way described above, if we consider only elements cnt[k] with left <= k < right (for simplicity, I'll consider elements which do not lie in this range to be equal to 0). Now we need to solve for a range [left, right]. Let's have in res1[] = solve(left, med) and in res2[] = solve(med, right), where med = (left + right) / 2. We need to put together res1[] and res2[] in order to obtain res[].</p><p>for (int i = left; i < med; ++i) res[i] = res1[i];</p><p>Numbers in [left, med] have most significant bit equal to 0. We can only keep it 0 and add what we calculated before. We can't add any element from res2[], because those elements have most significant bit equal to 1 and we're not allowed to change bit 0 into bit 1.</p><p>for (int i = med; i < right; ++i) res[i] = res1[i — med] + res2[i];</p><p>Here, most significant bit is 1. Adding res1[] corresponds to changing bit from 1 to 0, adding res2[] corresponds to leaving bit 1.</p><p>Of course, we need to threat the base case here, too. When left + 1 = right, res[left] = cnt[left]. We can keep only one array res[] instead of 3, I explained it this way only for simplicity. Also, there is no need for keeping separate arrays for res[] and cnt[], one can solve all task with only one array. In order to get res[], we simply call solve(0, 2^24).</p><p>Complexity of solution is O(2 ^ 24 * 24). I leave the proof homework, it's almost identical to complexity proof of D1 D "Author solution" (that with building a binary tree).</p><p>For a reference solution, check <a class=\"rated-user user-red\" href=\"/profile/Endagorion\" title=\"Grandmaster Endagorion\">Endagorion</a>'s AC source during contest. </p></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/384\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 225 (Div. 2)</a> </span>\r\n </div>\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/383\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 225 (Div. 1)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-12457-10531\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"12457\",\n blogEntryId: \"10476\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n <div style=\"font-size: 1.1rem;line-height: 11px;\">\r\n <img style=\"vertical-align: middle;\" src=\"//codeforces.org/s/81027/images/blog/tags.png\" title=\"Tags\" alt=\"Tags\"/>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=codeforces\" class=\"tag notice\" style=\"text-decoration: none;\">codeforces</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=225\" class=\"tag notice\" style=\"text-decoration: none;\">225</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=editorial\" class=\"tag notice\" style=\"text-decoration: none;\">editorial</a>\r\n </span>\r\n </div>\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-10531\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+418</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-10531\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/fchirica\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/fchirica\">\n fchirica\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Jan/20/2014 22:18\">10 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/10476#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/10476#comments\">\n 52\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"10547\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (45)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158582\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PAP\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/78534/avatar/d5bcc04085999f83.jpg'/> </a>\n <div><a href=\"/profile/PAP\" title=\"Candidate Master PAP\" class=\"rated-user user-violet\">PAP</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 22:40\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158582\" href=\"?#comment-158582\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158582\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"32\"\r\n data-commentUserId=\"78534\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+32</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158582\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>perfect editorial! thanks a lot!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158582 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158582 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158582\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158591\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/eduardische\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2320/avatar/3ac70493aa90ad2e.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/eduardische\" title=\"International Master eduardische\" class=\"rated-user user-orange\">eduardische</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 22:48\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158591\" href=\"?#comment-158591\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"158591\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"158591\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"10\"\r\n data-commentUserId=\"2320\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+10</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158591\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Just would like to report a typo in 383D contestants' solution: the formula computes D[i+1][j] and not D[i][j]. Thanks for the quick editorial!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158591 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158591 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158591\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158596\" commentParentId=\"158591\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/fchirica\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/57267/avatar/4e655c69b8ad66c2.jpg'/> </a>\n <div><a href=\"/profile/fchirica\" title=\"Candidate Master fchirica\" class=\"rated-user user-violet\">fchirica</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 22:52\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158596\" href=\"?#comment-158596\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-158591\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158596\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"15\"\r\n data-commentUserId=\"57267\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+15</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158596\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks. Fixed. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158596 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158596 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158596\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158598\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Mikester\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/109566/avatar/401b6d72d8f2e768.jpg'/> </a>\n <div><a href=\"/profile/Mikester\" title=\"Master Mikester\" class=\"rated-user user-orange\">Mikester</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 22:54\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158598\" href=\"?#comment-158598\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158598\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"13\"\r\n data-commentUserId=\"109566\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+13</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158598\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>elfus has some of the best rounds on Codeforces, and definitely the best editorials. Congratulations to you and Rares for the round !</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158598 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158598 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158598\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158599\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/iPs\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/144469/avatar/10358ae72910ceac.jpg'/> </a>\n <div><a href=\"/profile/iPs\" title=\"Expert iPs\" class=\"rated-user user-blue\">iPs</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 22:54\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158599\" href=\"?#comment-158599\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158599\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"33\"\r\n data-commentUserId=\"144469\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+33</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158599\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>best editorial I have ever seen in codeforces</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158599 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158599 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158599\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158600\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/bli0042\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/88584/avatar/51c3a9b55a3537fa.jpg'/> </a>\n <div><a href=\"/profile/bli0042\" title=\"Candidate Master bli0042\" class=\"rated-user user-violet\">bli0042</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 22:54\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158600\" href=\"?#comment-158600\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"158600\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"158600\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"88584\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158600\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For Div 2C, if A[i] = A[j] = 0 and we put i before j, won't j lose milk? Or am I misinterpreting the solution?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158600 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158600 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158600\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158601\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/aabs08\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/aabs08\" title=\"Expert aabs08\" class=\"rated-user user-blue\">aabs08</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 22:55\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158601\" href=\"?#comment-158601\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"158601\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"158601\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"9\"\r\n data-commentUserId=\"86699\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+9</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158601\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>One of the best editorials i came across in codeforces :D otherwise the editorial here are really very short and objective.</p><p>Every one here should write editorials like you :) !!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158601 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158601 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158601\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158607\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Xellos\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/69675/avatar/8526bcfc8e687b43.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/Xellos\" title=\"International Grandmaster Xellos\" class=\"rated-user user-red\">Xellos</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 23:03\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158607\" href=\"?#comment-158607\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"158607\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"158607\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"17\"\r\n data-commentUserId=\"69675\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+17</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158607\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Finally a tutorial worth upvoting!</p><p>I didn't really need to think about D. As soon as I saw the constraint on <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/986936bec272878d92f9c6fb0f0ce3c5b118cc0e.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />, I decided to try a DP on (position,sum) — it was a massive hint for me. Well, sometimes it just happens that there's a simple solution, which the author doesn't realize :D. Maybe this could be eliminated by some extensive "problem testing" by random capable people?</p><p>I guess I was also lucky in not trying to solve B. I solved in the order: A (because it's easy), C (because I like it), D (because it's easy) :D</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158607 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158607 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158607\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158610\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Mostafa_36a2\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/137637/avatar/28a01293a2b409.jpg'/> </a>\n <div><a href=\"/profile/Mostafa_36a2\" title=\"Specialist Mostafa_36a2\" class=\"rated-user user-cyan\">Mostafa_36a2</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 23:09\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158610\" href=\"?#comment-158610\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158610\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"-9\"\r\n data-commentUserId=\"137637\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-9</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158610\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I've found a very short solution for Div2 C , by zxz5759209</p> <pre><code>scanf("%d",&n);\n LL cnt=0,sum=0;\n for(int i=1;i<=n;i++)\n {\n scanf("%d",&x);\n cnt+=(LL)x;\n if(!x)sum+=cnt;\n }\n printf("%I64d\\n",sum);\n</code></pre></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158610 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158610 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158610\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158641\" commentParentId=\"158610\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Robert.One\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Robert.One\" title=\"Pupil Robert.One\" class=\"rated-user user-green\">Robert.One</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 01:27\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158641\" href=\"?#comment-158641\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-158610\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158641\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"150202\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158641\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I also had this solution and i got accepted but it took 1 hour to find it during the contest</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158641 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158641 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158641\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158612\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Darek_\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Darek_\" title=\"Specialist Darek_\" class=\"rated-user user-cyan\">Darek_</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 23:12\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158612\" href=\"?#comment-158612\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158612\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"152123\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158612\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks for an informative editorial.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158612 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158612 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158612\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158618\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Mostafa_36a2\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/137637/avatar/28a01293a2b409.jpg'/> </a>\n <div><a href=\"/profile/Mostafa_36a2\" title=\"Specialist Mostafa_36a2\" class=\"rated-user user-cyan\">Mostafa_36a2</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 23:25\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158618\" href=\"?#comment-158618\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"158618\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"158618\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"137637\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158618\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Unbelivable solution for Div2,B by Sick_Coder</p> <pre><code>cin >> n >> m >> k;\n cout << m * (m - 1) / 2 << "\\n";\n\n for (1, m, i)\n \tfor (i + 1, m, j)\n \t\tif (!k)\n \t\t\tcout << i << " " << j << "\\n";\n \t\telse\t\n \t\t\tcout << j << " " << i << "\\n";\n</code></pre></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158618 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158618 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158618\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158631\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mugurelionut\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/63702/avatar/45e4d5390c215090.jpg'/> </a>\n <div><a href=\"/profile/mugurelionut\" title=\"International Master mugurelionut\" class=\"rated-user user-orange\">mugurelionut</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/20/2014 23:57\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158631\" href=\"?#comment-158631\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158631\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"63702\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158631\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>A very good editorial, indeed! (but please don't forget about Div1E) And the problems were really nice. But I think problem B was tougher than it should have been for its amount of points. I've read some comments saying that problem B had too weak pretests (because so many solutions failed the final system tests). I would have to say that my experience with problem B was the exact opposite. I coded two wrong solutions (which failed some pretest or another) before eventually finding and implementing the right solution. So I'd say that problem B had good pretests :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158631 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158631 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158631\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158635\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/MohammadFatafta\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/148405/avatar/4276577919b9713d.jpg'/> </a>\n <div><a href=\"/profile/MohammadFatafta\" title=\"Specialist MohammadFatafta\" class=\"rated-user user-cyan\">MohammadFatafta</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 00:11\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158635\" href=\"?#comment-158635\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158635\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"148405\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158635\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>now this is a real editorial!! thanks guys :D</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158635 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158635 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158635\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158636\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/matrix\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/matrix\" title=\"Master matrix\" class=\"rated-user user-orange\">matrix</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 00:15\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158636\" href=\"?#comment-158636\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"158636\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"158636\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"16572\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158636\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Hi,</p><p>Great and fast editorial with complete details. </p><p>Thanks very much.</p><p>Edit: I think there is a small typo: "It’s not hard to see that answer for a fixed (i1, j1) is left[i1][j1] * value[2 * j1 – sum_of_elements_from_i1]." I guess you meant count[2 * j1 – sum_of_elements_from_i1].</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158636 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158636 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158636\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158637\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Kyuubi\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/83590/avatar/b87432a652bb276.jpg'/> </a>\n <div><a href=\"/profile/Kyuubi\" title=\"Expert Kyuubi\" class=\"rated-user user-blue\">Kyuubi</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 00:18\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158637\" href=\"?#comment-158637\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158637\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"2\"\r\n data-commentUserId=\"83590\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+2</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158637\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Best Editorials I have seen on codeforces yet! :D</p><p>For Propagating tree, how do we keep track of alternating levels in the arrays we created using DFS ? </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158637 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158637 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158637\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158640\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/k_____k\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/60285/avatar/422359e1ae9d666c.jpg'/> </a>\n <div><a href=\"/profile/k_____k\" title=\"Expert k_____k\" class=\"rated-user user-blue\">k_____k</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 01:07\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158640\" href=\"?#comment-158640\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158640\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"2\"\r\n data-commentUserId=\"60285\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+2</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158640\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Best Editorials Ever ! #thanks to the authors, for posting alternative solutions of contestants also. Great start in 2014. #Looking Forward.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158640 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158640 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158640\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158658\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/sillycross\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/41652/avatar/58966d0c793c6394.jpg'/> </a>\n <div><a href=\"/profile/sillycross\" title=\"Grandmaster sillycross\" class=\"rated-user user-red\">sillycross</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 07:49\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158658\" href=\"?#comment-158658\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158658\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"9\"\r\n data-commentUserId=\"41652\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+9</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158658\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Div1 E can be solved in O(2^24*24) or O(2^24+2^12*n)..</p><p>O(2^24*24): dp[i][s] means the sum of all contributions of subset s where all digits are same as s except the last i digits.. </p><p>O(2^24+2^12*n): the length of word is only 3. We divide the 24 letters in half, calculate the answer for all first 12 letters and all last 12 letters and merge them with brute-force. This can be solved in O(2^24). Then we subtract the words that are counted twice: these words are words that have 2 letters in first half and 1 in second half, or 2 in second half and 1 in first half. Let's consider the first case: for each subset of first 12 letters we check each word whether it has exactly 2 letters in this half, if so, we can say all masks in another half that contains the third letter need to be subtracted by 1. This can be solved in 2^12*(2^12+n). Same algorithm can be used to solve the second case. Although this algorithm runs slower than O(2^24*24) bcuz of its larger constant... </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158658 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158658 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158658\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158663\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/VeniVidiVici\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/VeniVidiVici\" title=\"Candidate Master VeniVidiVici\" class=\"rated-user user-violet\">VeniVidiVici</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 09:39\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158663\" href=\"?#comment-158663\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158663\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"149163\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158663\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Very nice editorial! Disappointed in Div 2B though, really expected the "real" problem rather than just insertion sort but that's what you get for not reading carefully ;)</p><p>However, does anyone have an accepted solution that is "real" (e.g. finds the minimum number of operations necessary and prints such a solution)? I was close but my computer died during contest and I haven't tried so much since (of course you can do O((mn)^2) easily but this is way too slow, there should be a O(n*m^2) solution but again my computer was unable to operate). My approach was to make 2-D boolean array to check if a swap is necessary, but I'm not sure if order of operations will end up being a big problem.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158663 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158663 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158663\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158685\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/LegendaryGrandmaster\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/142091/avatar/a3a5a4b5c26ac419.jpg'/> </a>\n <div><a href=\"/profile/LegendaryGrandmaster\" title=\"Specialist LegendaryGrandmaster\" class=\"rated-user user-cyan\">LegendaryGrandmaster</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 14:34\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158685\" href=\"?#comment-158685\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158685\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"142091\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158685\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>One of the best codeforces editorials ever! Thanks!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158685 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158685 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158685\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158687\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/BENYAM1N\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/84938/avatar/d2ae2657d8898e38.jpg'/> </a>\n <div><a href=\"/profile/BENYAM1N\" title=\"Master BENYAM1N\" class=\"rated-user user-orange\">BENYAM1N</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 15:24\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158687\" href=\"?#comment-158687\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"158687\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"158687\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"84938\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158687\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks a lot. very good contest and good editorial too!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158687 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158687 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158687\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158689\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/JuanMata\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/82548/avatar/a7d69af7b441c6d7.jpg'/> </a>\n <div><a href=\"/profile/JuanMata\" title=\"Expert JuanMata\" class=\"rated-user user-blue\">JuanMata</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 15:47\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158689\" href=\"?#comment-158689\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158689\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"82548\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158689\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>this is one of the best editorials on CF ever!!!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158689 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158689 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158689\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158700\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Vicfred\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/76941/avatar/d067b7433ec39337.jpg'/> </a>\n <div><a href=\"/profile/Vicfred\" title=\"Pupil Vicfred\" class=\"rated-user user-green\">Vicfred</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 16:25\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158700\" href=\"?#comment-158700\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158700\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"11\"\r\n data-commentUserId=\"76941\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+11</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158700\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>The best editorial I've read in a while here, thanks.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158700 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158700 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158700\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158727\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/beecoder\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/beecoder\" title=\"Pupil beecoder\" class=\"rated-user user-green\">beecoder</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2014 21:13\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158727\" href=\"?#comment-158727\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158727\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"89551\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158727\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Hi, The way I print answers for 'Coder Problem' is as follows. This takes 124 ms. is there a way to print the answers faster ? </p> <pre><code> \tfor (int i = 0 ; i < number ; i ++ ) { \n \t\tfor (int k = 0 ; k < number ; k ++ ) { \n \t\t\tif (flag) {\n \t\t\t\tif ( k % 2 == 1) out.print('.');\n \t\t\t\tif( k% 2 == 0 ) out.print('C');\n \t\t\t} else {\n \t\t\tif ( k % 2 == 1) out.print('C');\n \t\t\tif( k% 2 == 0 ) out.print('.');\t\n \t\t\t}\n \t\t}\n \t\tif (flag) flag = false;\n \t\telse flag = true;\n \t\tout.print("\\n");\n \t}\n \n</code></pre></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158727 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158727 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158727\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158742\" commentParentId=\"158727\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Mostafa_36a2\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/137637/avatar/28a01293a2b409.jpg'/> </a>\n <div><a href=\"/profile/Mostafa_36a2\" title=\"Specialist Mostafa_36a2\" class=\"rated-user user-cyan\">Mostafa_36a2</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/22/2014 14:00\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158742\" href=\"?#comment-158742\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-158727\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158742\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"137637\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158742\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>As the line contains k characters , and every odd lines are identical , also the even ones,</p><p>you can build 2 strings [C.C.C.C] and [.C.C.C.] and print them alternately </p><p>[In my opinion Java is slow language any way ]</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158742 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158742 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158742\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158752\" commentParentId=\"158727\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/t_thirupathi\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/146179/avatar/98c28348196ce4ca.jpg'/> </a>\n <div><a href=\"/profile/t_thirupathi\" title=\"Specialist t_thirupathi\" class=\"rated-user user-cyan\">t_thirupathi</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/22/2014 18:19\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158752\" href=\"?#comment-158752\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-158727\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158752\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"146179\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158752\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Modulo operations are time consuming.</p><p>To check if a number <code>n</code> is odd, you could use <code>if (n & 1)</code></p> <pre><code>for (int i = 0; i < n; i++) {\n for (int j = 0; j < n; j++)\n if ((i + j) & 1)\n out.print('.');\n else \n out.print('C');\n out.print('\\n');\n}\n</code></pre></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158752 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158752 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158752\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158745\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/JuanMata\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/82548/avatar/a7d69af7b441c6d7.jpg'/> </a>\n <div><a href=\"/profile/JuanMata\" title=\"Expert JuanMata\" class=\"rated-user user-blue\">JuanMata</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/22/2014 14:49\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158745\" href=\"?#comment-158745\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"158745\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"158745\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"82548\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158745\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>i think there is a small bug in the <a href=\"http://pastie.org/8651824\">pastie link</a> u posted for the solution of Div1 C problem.</p><p>i submitted almost exact copy of it (<a href=\"/contest/383/submission/5769615\" title=\"Submission 5769615 by JuanMata\">5769615</a>), but got WA#6. then i found the bug, corrected it and resubmitted (<a href=\"/contest/383/submission/5769890\" title=\"Submission 5769890 by JuanMata\">5769890</a>) and got AC.</p><p>referring to my two submissions, corrections in line <strong>68</strong> (last statement of <strong>dfs</strong>) and line <strong>109</strong> (the second call to <strong>update</strong>).</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158745 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158745 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158745\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"615836\" commentParentId=\"158745\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/adityakr007\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/adityakr007\" title=\"Expert adityakr007\" class=\"rated-user user-blue\">adityakr007</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/05/2020 18:54\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-615836\" href=\"?#comment-615836\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-158745\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"615836\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"866209\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-615836\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can you explain what exactly have you done in your submission (<a href=\"/contest/383/submission/5769890\" title=\"Submission 5769890 by JuanMata\">5769890</a>) for this problem?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-615836 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-615836 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-615836\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"629531\" commentParentId=\"615836\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/JuanMata\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/82548/avatar/a7d69af7b441c6d7.jpg'/> </a>\n <div><a href=\"/profile/JuanMata\" title=\"Expert JuanMata\" class=\"rated-user user-blue\">JuanMata</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/25/2020 18:14\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-629531\" href=\"?#comment-629531\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-615836\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"629531\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"82548\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-629531\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>sorry bro i've forgotten ... that was over 6yrs ago now!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-629531 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-629531 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-629531\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158751\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/TempuX\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/30820/avatar/c50adc243ea4e2fa.jpg'/> </a>\n <div><a href=\"/profile/TempuX\" title=\"Specialist TempuX\" class=\"rated-user user-cyan\">TempuX</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/22/2014 17:07\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158751\" href=\"?#comment-158751\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158751\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"30820\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158751\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Hi, I tried to implement the Volcano problem in the way explained in the editorial but I'm getting TLE. Here is my code <a href=\"//codeforces.com/contest/384/submission/5770818\">submission</a> What am I doing wrong ? Thanks anyway.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158751 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158751 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158751\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158811\" commentParentId=\"158751\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/TempuX\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/30820/avatar/c50adc243ea4e2fa.jpg'/> </a>\n <div><a href=\"/profile/TempuX\" title=\"Specialist TempuX\" class=\"rated-user user-cyan\">TempuX</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/23/2014 17:29\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158811\" href=\"?#comment-158811\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-158751\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"158811\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"30820\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158811\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Turns out my binary search is causing the problem and I don't see what is wrong with it... I would appreciate any ideas.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158811 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158811 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158811\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159025\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/bboy_drain\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/76710/avatar/e0feb3aa135911d4.jpg'/> </a>\n <div><a href=\"/profile/bboy_drain\" title=\"Expert bboy_drain\" class=\"rated-user user-blue\">bboy_drain</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/25/2014 01:34\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159025\" href=\"?#comment-159025\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159025\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"76710\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159025\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Wow! This really helped me a lot! Very detailed explanations!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159025 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159025 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159025\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159092\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/AlexandruValeanu\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/131651/avatar/1c7d989c45052941.jpg'/> </a>\n <div><a href=\"/profile/AlexandruValeanu\" title=\"Candidate Master AlexandruValeanu\" class=\"rated-user user-violet\">AlexandruValeanu</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/25/2014 21:27\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159092\" href=\"?#comment-159092\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159092\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"131651\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159092\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>It was by far your best round on Codeforces, <a class=\"rated-user user-blue\" href=\"/profile/fchirica\" title=\"Expert fchirica\">fchirica</a>. The problems were great, very different one from the other and some of them didn't require any algorithmic skills at all. Good job!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159092 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159092 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159092\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159261\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lawsonh\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/lawsonh\" title=\"Expert lawsonh\" class=\"rated-user user-blue\">lawsonh</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/28/2014 06:33\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159261\" href=\"?#comment-159261\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"159261\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"159261\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"55047\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159261\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>for div1 383C should end[5] = 7? edit: nvm drew the tree wrong</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159261 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159261 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159261\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159474\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/tiagonapoli\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/150060/avatar/6615fcab66b23361.jpg'/> </a>\n <div><a href=\"/profile/tiagonapoli\" title=\"Candidate Master tiagonapoli\" class=\"rated-user user-violet\">tiagonapoli</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/30/2014 22:28\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159474\" href=\"?#comment-159474\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159474\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"150060\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159474\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Great Editorial! Thanks so much, i've learned a lot!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159474 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159474 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159474\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159707\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lchf\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/60496/avatar/e9939e755252ec16.jpg'/> </a>\n <div><a href=\"/profile/lchf\" title=\"Candidate Master lchf\" class=\"rated-user user-violet\">lchf</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/02/2014 17:28\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159707\" href=\"?#comment-159707\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159707\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"60496\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159707\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Amazing solution by Endagorion.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159707 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159707 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159707\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"177400\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/sourabh912\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/57335/avatar/bf83b9340e3cbb17.jpg'/> </a>\n <div><a href=\"/profile/sourabh912\" title=\"Specialist sourabh912\" class=\"rated-user user-cyan\">sourabh912</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/12/2014 20:39\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-177400\" href=\"?#comment-177400\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"177400\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"57335\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-177400\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In Div 1C problem, I could not understand how it can be solved using single fenwick tree from the solution link in the editorial. Can anyone please help.</p><p>Thanks</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-177400 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-177400 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-177400\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"291157\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/l_Love_KFC\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/258117/avatar/bbaec3ce1613f5bd.jpg'/> </a>\n <div><a href=\"/profile/l_Love_KFC\" title=\"Expert l_Love_KFC\" class=\"rated-user user-blue\">l_Love_KFC</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Apr/29/2016 08:23\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-291157\" href=\"?#comment-291157\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"291157\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"258117\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-291157\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In Div.1 A I didn't catch the point that in 1st, quote : "If we put i before j, no additional cost will be added. Since j is in right of i and i only adds cost when it finds elements in left of i, j won’t be affected when processing i." Won't we lose milk if we put firstly i, in case of that j sees that and loses milk? Or am I misunderstanding the task? </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-291157 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-291157 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-291157\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"309434\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/haleyk100198\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/416324/avatar/f2d97d505af17e9d.jpg'/> </a>\n <div><a href=\"/profile/haleyk100198\" title=\"Candidate Master haleyk100198\" class=\"rated-user user-violet\">haleyk100198</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/11/2016 06:32\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-309434\" href=\"?#comment-309434\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"309434\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"416324\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-309434\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I wonder how the problem Div1C can be converted to a segment tree lazy propagation implementation question, for trees like (1-2 2-3 3-4 4-5 .... 9999-E4) how can we achieve O(log N) update time?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-309434 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-309434 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-309434\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"310847\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/my_new_handle\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/233736/avatar/24128c61b65e3262.jpg'/> </a>\n <div><a href=\"/profile/my_new_handle\" title=\"Candidate Master my_new_handle\" class=\"rated-user user-violet\">my_new_handle</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/20/2016 14:49\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-310847\" href=\"?#comment-310847\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"310847\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"233736\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-310847\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>а зачем в таске б массив он влияет как-то?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-310847 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-310847 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-310847\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"332763\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/rhezo\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/305605/avatar/aa59e9c2ec688c6a.jpg'/> </a>\n <div><a href=\"/profile/rhezo\" title=\"Candidate Master rhezo\" class=\"rated-user user-violet\">rhezo</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Dec/24/2016 07:56\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-332763\" href=\"?#comment-332763\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"332763\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"305605\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-332763\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I'm getting Runtime Error on test 44 in <a href=\"//codeforces.com/problemset/problem/383/C\">Propogating Tree</a>. </p><p>This is because of stack overflow right? That test has N = 2e5 and for a straight chain of nodes, I'll get a runtime error with a recursive DFS right? What to do in such cases? </p><p>I can write an iterative DFS, but I do HLD recursively too and I'm not quite sure if I can write an iterative HLD. </p><p>Can anyone tell me what to do in such cases? I'm assuming that I got the runtime error due to stackoverflow from DFS.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-332763 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-332763 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-332763\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"346070\" commentParentId=\"332763\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/yinanzhu\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/520731/avatar/d61a58bf5df54146.jpg'/> </a>\n <div><a href=\"/profile/yinanzhu\" title=\"Expert yinanzhu\" class=\"rated-user user-blue\">yinanzhu</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/26/2017 07:18\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-346070\" href=\"?#comment-346070\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-332763\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"346070\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"520731\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-346070\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I used recursive dfs and passed all test case. Test 44 cost 1.5 s</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-346070 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-346070 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-346070\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"387028\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/blue__legend\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/blue__legend\" title=\"Expert blue__legend\" class=\"rated-user user-blue\">blue__legend</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/23/2017 07:16\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-387028\" href=\"?#comment-387028\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"387028\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"284949\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-387028\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>How to solve DIV 1 C using one fenwick or segment tree. The code link given in editorial is not working.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-387028 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-387028 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-387028\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"757423\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Ausmosian\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Ausmosian\" title=\"Expert Ausmosian\" class=\"rated-user user-blue\">Ausmosian</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/05/2021 15:05\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-757423\" href=\"?#comment-757423\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"757423\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"727283\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-757423\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>[<a href=\"https://codeforces.com/contest/383/problem/C\">384E — Propagating tree</a>] Can also be solved using Square Root Decomposition. <a href=\"https://codeforces.com/contest/383/submission/106526543\">Submission</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-757423 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-757423 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-757423\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"838255\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/3hill\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1621900/avatar/478297db63bad207.jpg'/> </a>\n <div><a href=\"/profile/3hill\" title=\"Expert 3hill\" class=\"rated-user user-blue\">3hill</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/11/2021 17:02\">2 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-838255\" href=\"?#comment-838255\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"838255\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1621900\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-838255\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I am Getting MLE on TC-53<br />Can someone review my code and figure out the issue ,Thanks</p> <ul> <li><a href=\"https://codeforces.com/contest/383/problem/C\">Problem</a></li> <li><a href=\"https://codeforces.com/contest/383/submission/128510633\">My code</a></li> </ul></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-838255 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-838255 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-838255\">\r\n </ul>\r\n</div>\r\n <br/>\r\n\r\n<div id=\"editBox-10547\" style=\"width:50em;display:none;\">\r\n <div class=\"previewBody\" style=\"border: 1px solid #d4d4d4; margin-bottom: 0.5em; padding: 0.25em; display:none;\"> </div>\r\n <div style=\"width: 1px\"> </div>\r\n <div class=\"commentLocale\" style=\"position: relative; top: 0.5em;left:4px;display: none;\">\r\n <input type=\"radio\" name=\"locale\" value=\"en\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In English</span>\r\n <input style=\"margin-left:1em\" type=\"radio\" name=\"locale\" value=\"ru\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In Russian</span>\r\n </div>\r\n <textarea data-drafts-id=\"CommentReplyFrame\" class=\"wysiwyg\" name=\"editContent\" rows=\"20\" style=\"width:99%;\"></textarea>\r\n <div class=\"error error__content\"></div>\r\n <div style=\"text-align:center;\">\r\n <input type=\"button\" name=\"preview\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Preview\"/>\r\n <input type=\"button\" name=\"save\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Save\"/>\r\n </div>\r\n</div>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n\r\nvar firstPreview10547 = true;\r\nvar lastPreviewContent10547 = '';\r\n\r\nif (!window.moveCommentRevision) {\r\n moveCommentRevision = function(e, dir) {\r\n var p = e.parent();\r\n var revisionCount = parseInt(p.attr(\"revisionCount\"));\r\n var revision = parseInt(p.attr(\"revision\"));\r\n var next = revision + dir;\r\n var commentId = p.attr(\"commentId\");\r\n if (next >= 1 && next <= revisionCount) {\r\n $.post(\r\n \"/data/comment-data\",\r\n {action: \"revision\", commentId: commentId, revision: next},\r\n function(json) {\r\n if (json.success == \"true\") {\r\n var parentDiv = e;\r\n\r\n while (parentDiv !== null && (parentDiv[0].nodeName.toLowerCase() !== \"td\" || !parentDiv.hasClass(\"right\"))) {\r\n parentDiv = parentDiv.parent();\r\n }\r\n\r\n if (parentDiv === null) {\r\n return;\r\n }\r\n\r\n parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\").html(json.content);\r\n Codeforces.setupSpoilers(parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\"));\r\n p.attr(\"revision\", next);\r\n p.find(\"span.revision\").text(next);\r\n if (next == 1) {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"visible\");\r\n }\r\n if (next == revisionCount) {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"visible\");\r\n }\r\n\r\n window.updateTypography();\r\n MathJax.Hub.Typeset();\r\n } else {\r\n alert(e.error);\r\n }\r\n },\r\n \"json\"\r\n );\r\n }\r\n };\r\n}\r\n\r\n$(\"div[commentableId=10547] a.leftRevision\").click(function () {\r\n window.moveCommentRevision($(this), -1);\r\n return false;\r\n});\r\n\r\n$(\"div[commentableId=10547] a.rightRevision\").click(function () {\r\n window.moveCommentRevision($(this), +1);\r\n return false;\r\n});\r\n\r\n\r\n\r\n });\n </script>\n\r\n\r\n <script src=\"//codeforces.org/s/81027/js/swfobject-2.2.min.js\" type=\"text/javascript\"></script>\n <script src=\"//codeforces.org/s/81027/js/ftaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n if (window.evercookie) {\n var ec = new evercookie({\n history: false,\n silverlight: false,\n baseurl: '',\n asseturi: '/assets',\n phpuri: '/2fdcd78',\n pngPath: '/eps',\n etagPath: '/ees',\n cachePath: '/ecs'\n });\n\n var randomNumber = function () {\n return Math.random().toString(36).substr(2);\n };\n\n var randomToken = function () {\n return (randomNumber() + randomNumber()).substring(0, 18);\n };\n\n window._ftaa = \"\";\n\n ec.get(\"70a7c28f3de\", function (value) {\n window._ftaa = value;\n if (!window._ftaa) {\n window._ftaa = randomToken();\n ec.set(\"70a7c28f3de\", window._ftaa);\n }\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n } else {\n window._ftaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\n <script src=\"//codeforces.org/s/81027/js/bfaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n var fpCallback = function() {\n Fingerprint2.get({}, function(components) {\n window._bfaa = Fingerprint2.x64hash128(components.map(function (pair) { return pair.value }).join(), 31);\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n };\n if (typeof Fingerprint2 !== 'undefined') {\n if (window.requestIdleCallback) {\n requestIdleCallback(fpCallback)\n } else {\n setTimeout(fpCallback, 500)\n }\n } else {\n window._bfaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"a.new-root-comment\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n\r\n $(\".comment-table .reply a\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".vote-for-comment\").mouseover(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").mouseout(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").click(function () {\r\n var vote = $(this);\r\n var commentId = $(this).parent().attr(\"commentid\");\r\n var commentRating = $(this).parent().attr(\"data-commentRating\");\r\n var direction = $(this).attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n $.post(\"/data/comment/vote\", {commentId: commentId, _tta: Codeforces.tta(), vote: direction, commentRating: commentRating}, function(data) {\r\n if (direction != 0 && !ownComment && data[\"success\"] == \"true\") {\r\n vote.parent().find(\".vote-for-comment\").attr(\"voteDirection\", 0);\r\n if (direction == 1)\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n else {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.closest(\".CommentVoteFrame\").find(\".ComplaintFrame\").css(\"display\", \"inline-block\");\r\n }\r\n vote.find(\"img\").attr(\"popacity\", \"1.0\");\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n vote.parent().find(\".commentRating\").html(data[\"commentRating\"]);\r\n }\r\n Codeforces.showMessage(data[\"message\"]);\r\n }, \"json\");\r\n return false;\r\n });\r\n\r\n $(\".negative-comment-vote\").closest(\".comment-table\").addClass(\"comment-bad\");\r\n\r\n $(\".troll-comment-vote\").closest(\".comment\").css(\"display\", \"none\");\r\n\r\n $(\".too-negative-comment-vote\").closest(\".comment-table\").each(function () {\r\n var e = $(this);\r\n e.addClass(\"comment-too-bad\");\r\n var commentId = e.attr(\"commentId\");\r\n $(\"<div class='bad-comment-replacement ttypography'>The comment is hidden because of too negative feedback, click <a href=# class=show-bad-comment-link>here</a> to view it</div>\").appendTo(\r\n e.find(\".right\")\r\n );\r\n e.find(\".comment-content\").hide();\r\n e.find(\".show-bad-comment-link\").click(function () {\r\n e.find(\".comment-content\").show();\r\n e.find(\".bad-comment-replacement\").hide();\r\n return false;\r\n });\r\n });\r\n });\n </script>\n </div>\r\n\r\n <style type=\"text/css\">\r\n .new-comments-box {\r\n padding: 0.5em;\r\n width: 22px;\r\n font-size: 1.3rem;\r\n font-weight: bold !important;\r\n\r\n position: fixed;\r\n top: 40%;\r\n right: 0;\r\n opacity: 0.2;\r\n color: white;\r\n text-align: center;\r\n\r\n border: 1px solid #222;\r\n background-color: #888 !important;\r\n border-radius: 3px;\r\n -moz-border-radius: 3px;\r\n -webkit-border-radius: 3px;\r\n }\r\n\r\n .new-comments-box:hover {\r\n opacity: 1;\r\n }\r\n\r\n .new-comments-box .dir:hover {\r\n background: #3B5998 !important;\r\n cursor: pointer;\r\n }\r\n </style>\r\n\r\n <div class=\"new-comments-box\" data-position=\"outside\" data-index=\"-1\" style=\"display: none;\">\r\n <div class=\"up dir\" title=\"Ctrl+Up\">↑<hr/>\r\n </div>\r\n <div class=\"info\" title=\"New comments\"></div>\r\n <div class=\"down dir\" title=\"Ctrl+Down\">\r\n <hr/>↓\r\n </div>\r\n </div>\r\n\r\n <script>\r\n $(\".show-archived-checkbox\").change(function () {\r\n const checked = $(this).is(\":checked\");\r\n $.post(\"/data/comment-data\", {action: \"setShowArchived\", checked}, function (json) {\r\n if (json[\"success\"] !== \"true\") {\r\n alert(json[\"error\"]);\r\n } else {\r\n if (checked) {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are now displayed\")\r\n } else {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are no longer displayed\")\r\n }\r\n }\r\n });\r\n return false;\r\n });\r\n\r\n function gotoComment(direction) {\r\n var box = $(\".new-comments-box\");\r\n var index = parseInt(box.attr(\"data-index\"));\r\n if (index == -1)\r\n index = 0;\r\n else\r\n index = Math.max(0, Math.min(parseInt(box.find(\".info\").text()) - 1, index + direction));\r\n box.attr(\"data-index\", index);\r\n var comment = $($(\".comment .highlight-blue[commentId]\").get(index));\r\n $('html, body').animate({\r\n 'scrollTop': Math.max(0, comment.offset().top - ($(window).height() - comment.height()) / 2)\r\n });\r\n return false;\r\n }\r\n\r\n $(\".new-comments-box .down\").click(function () {\r\n return gotoComment(1);\r\n });\r\n\r\n $(\".new-comments-box .up\").click(function () {\r\n return gotoComment(-1);\r\n });\r\n\r\n $(document).keydown(function (e) {\r\n var code = (e.keyCode ? e.keyCode : e.which);\r\n if (e.ctrlKey) {\r\n if (code == 38 || code == 40) {\r\n gotoComment(code - 39);\r\n }\r\n }\r\n });\r\n\r\n var newCommentCount = $(\".comment .highlight-blue[commentId]\").length;\r\n if (newCommentCount > 0) {\r\n $(\".new-comments-box .info\").text(newCommentCount);\r\n $(\".new-comments-box\").show();\r\n }\r\n\r\n $('table.comment-table').mouseenter(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").addClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n\r\n $('table.comment-table').mouseleave(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").removeClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n </script>\r\n\r\n\r\n\r\n <script>\r\n function adjustTopicComplainFrames() {\r\n let topicIds = [];\r\n\r\n $(\".has-topic-id\").each(function () {\r\n const $this = $(this);\r\n const topicId = $this.attr(\"topicId\");\r\n if (topicId) {\r\n topicIds.push(topicId);\r\n }\r\n });\r\n\r\n $.post(\"/data/topics\", {\r\n action: \"findComplainableTopicIds\",\r\n topicIds: topicIds.join(\",\")\r\n }, function (json) {\r\n if (json[\"success\"] === \"true\") {\r\n for (const topicId of json[\"complainableTopicIds\"].split(\",\")) {\r\n $(\".has-topic-id[topicId=\" + topicId + \"]\").each(function () {\r\n $(this).find(\".meta .ComplaintFrame\").css(\"display\", \"inline-block\");\r\n });\r\n }\r\n }\r\n }, \"json\");\r\n }\r\n\r\n $(function () {\r\n adjustTopicComplainFrames();\r\n })\r\n </script>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-10531\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 10531, _tta: Codeforces.tta(), topicRevisionId: 36233, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-10531\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 10531, _tta: Codeforces.tta(), topicRevisionId: 36233, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n </div>\r\n </div>\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 22:13:02</span> (h1).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/81027/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/81027/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/81027/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/81027/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-81027.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'81287584a8369d92',t:'MTY5NjcwNTk4Mi42NDcwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"}}},{"rowIdx":1944,"cells":{"problem_id":{"kind":"string","value":"385A"},"contest":{"kind":"string","value":"385"},"problem":{"kind":"string","value":"A"},"lang":{"kind":"string","value":"en"},"problem_title":{"kind":"string","value":"A. Bear and Raspberry"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">A. Bear and Raspberry</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>The bear decided to store some raspberry for the winter. He cunningly found out the price for a barrel of honey in kilos of raspberry for each of the following <span class=\"tex-span\"><i>n</i></span> days. According to the bear's data, on the <span class=\"tex-span\"><i>i</i></span>-th <span class=\"tex-span\">(1 ≤ <i>i</i> ≤ <i>n</i>)</span> day, the price for one barrel of honey is going to is <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span> kilos of raspberry.</p><p>Unfortunately, the bear has neither a honey barrel, nor the raspberry. At the same time, the bear's got a friend who is ready to lend him a barrel of honey for exactly one day for <span class=\"tex-span\"><i>c</i></span> kilograms of raspberry. That's why the bear came up with a smart plan. He wants to choose some day <span class=\"tex-span\"><i>d</i></span> <span class=\"tex-span\">(1 ≤ <i>d</i> < <i>n</i>)</span>, lent a barrel of honey and immediately (on day <span class=\"tex-span\"><i>d</i></span>) sell it according to a daily exchange rate. The next day <span class=\"tex-span\">(<i>d</i> + 1)</span> the bear wants to buy a new barrel of honey according to a daily exchange rate (as he's got some raspberry left from selling the previous barrel) and immediately (on day <span class=\"tex-span\"><i>d</i> + 1</span>) give his friend the borrowed barrel of honey as well as <span class=\"tex-span\"><i>c</i></span> kilograms of raspberry for renting the barrel.</p><p>The bear wants to execute his plan at most once and then hibernate. What maximum number of kilograms of raspberry can he earn? Note that if at some point of the plan the bear runs out of the raspberry, then he won't execute such a plan.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains two space-separated integers, <span class=\"tex-span\"><i>n</i></span> and <span class=\"tex-span\"><i>c</i></span> <span class=\"tex-span\">(2 ≤ <i>n</i> ≤ 100, 0 ≤ <i>c</i> ≤ 100)</span>, — the number of days and the number of kilos of raspberry that the bear should give for borrowing the barrel.</p><p>The second line contains <span class=\"tex-span\"><i>n</i></span> space-separated integers <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">1</sub>, <i>x</i><sub class=\"lower-index\">2</sub>, ..., <i>x</i><sub class=\"lower-index\"><i>n</i></sub></span> <span class=\"tex-span\">(0 ≤ <i>x</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 100)</span>, the price of a honey barrel on day <span class=\"tex-span\"><i>i</i></span>.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print a single integer — the answer to the problem.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>5 1<br/>5 10 7 3 20<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>3<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>6 2<br/>100 1 10 40 10 40<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>97<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3 0<br/>1 2 3<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>0<br/></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>In the first sample the bear will lend a honey barrel at day 3 and then sell it for 7. Then the bear will buy a barrel for 3 and return it to the friend. So, the profit is (7 - 3 - 1) = 3.</p><p>In the second sample bear will lend a honey barrel at day 1 and then sell it for 100. Then the bear buy the barrel for 1 at the day 2. So, the profit is (100 - 1 - 2) = 97.</p></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"ffb6822e25ac8c65d4435d23638f73ad\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - A - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"3200a641fa0ca6f78af7a41b57e5016ab7be9096\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - A - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/73366/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/73366/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/73366/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/73366/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/73366/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/73366/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/73366/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/73366/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/73366/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/73366/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/73366/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/73366/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/73366/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/73366/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/sidebar-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/a037fe51637846d9c7c725713cd840ea/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='ffb6822e25ac8c65d4435d23638f73ad'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/73366/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/73366/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fcontest%2F385%2Fproblem%2FA%3Flocale%3Den\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"current\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='ffb6822e25ac8c65d4435d23638f73ad'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:100%;\"><a style=\"color: black\" href=\"/contest/385\">Codeforces Round 226 (Div. 2)</a></th>\n </tr>\n <tr>\n <td class=\"left bottom\" colspan=\"1\"><span class=\"contest-state-phase\">Finished</span></td>\n </tr>\n </tbody>\n </table>\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Practice?\n <div class=\"top-links\">\n </div>\n </div>\n<div>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Want to solve the contest problems after the official contest ends? Just register for practice and you will be able to submit solutions.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"\" method=\"post\"><input type='hidden' name='csrf_token' value='ffb6822e25ac8c65d4435d23638f73ad'/>\r\n <input type=\"hidden\" name=\"action\" value=\"registerForPractice\"/>\r\n <input type=\"submit\" name=\"submit\" value=\"Register for practice\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div> \r\n</div>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox ContestVirtualFrame borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Virtual participation <i class=\"sidebar-caption-icon las la-angle-down\"></i>\r\n\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\" \"\r\n\r\n data-page-url=\"/data/sidebarFrames\"\r\n\r\n>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests.\n\nIf you've seen these problems, a virtual contest is not for you - solve these problems in the archive.\n\nIf you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.\n\nNever use someone else's code, read the tutorials or communicate with other person during a virtual contest.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"/contest/385/virtual\" method=\"get\">\r\n <input type=\"submit\" name=\"submit\" value=\"Start virtual contest\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div>\r\n</div>\r\n <script>\r\n $(function () {\r\n $(\".ContestVirtualFrame .sidebar-caption-icon\").click(function() {\r\n $(this).toggleClass(\"la-angle-down la-angle-right\");\r\n const $target = $(this).parent().next();\r\n $target.toggle();\r\n const dataPageUrl = $target.attr(\"data-page-url\");\r\n const collapsed = $(this).hasClass(\"la-angle-right\");\r\n const params = {\r\n action: \"setCollapsed\",\r\n sidebarFrameSimpleClassName: \"ContestVirtualFrame\",\r\n collapsed\r\n };\r\n $.each($target[0].attributes, function(i, a) {\r\n const name = a.name;\r\n if (name.startsWith(\"data-extra-key-\")) {\r\n const key = a.value;\r\n const keyIndex = parseInt(name.substring(\"data-extra-key-\".length));\r\n const value = $target.attr(\"data-extra-value-\" + keyIndex);\r\n params[key] = value;\r\n }\r\n });\r\n $.post(dataPageUrl, params, function (result) {\r\n if (result[\"success\"] !== \"true\") {\r\n Codeforces.showMessage(\"Failed to save collapsed state.\");\r\n }\r\n }, \"json\");\r\n return false;\r\n });\r\n })\r\n </script>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Problem tags\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Brute force\">\r\n brute force\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Greedy algorithms\">\r\n greedy\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Implementation problems, programming technics, simulation\">\r\n implementation\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Difficulty\">\r\n *1000\r\n</span>\r\n </div>\n <div style=\"clear:both;text-align:right;font-size:1.1rem;\">\r\n <span title=\"Please login into the Codeforces\" class=\"notice\">No tag edit access</span>\r\n </div>\r\n</div>\r\n </div>\n\r\n<form id=\"addTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='ffb6822e25ac8c65d4435d23638f73ad'/>\r\n <input name=\"action\" type=\"hidden\" value=\"addTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"5931\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<form id=\"removeTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='ffb6822e25ac8c65d4435d23638f73ad'/>\r\n <input name=\"action\" type=\"hidden\" value=\"removeTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"5931\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<script type=\"text/javascript\">\r\n $(\".tag-box img\").click(function () {\r\n var tagName = $(this).attr(\"value\");\r\n Codeforces.confirm(\"Are you sure you want to remove this tag?\", function () {\r\n $(\"#removeTagForm input[name=tagName]\").val(tagName);\r\n $(\"#removeTagForm\").submit();\r\n }, function () {\r\n }, \"Yes\", \"No\");\r\n });\r\n\r\n $(\"#addTagLink\").click(function () {\r\n $(this).hide();\r\n $(\"#addTagLabel\").show();\r\n return false;\r\n });\r\n\r\n $(\"#addTagSelect\").change(function () {\r\n var tagName = $(this).val();\r\n if (tagName === \"\") {\r\n $(\"#addTagLabel\").hide();\r\n $(\"#addTagLink\").show();\r\n } else {\r\n $(\"#addTagForm input[name=tagName]\").val(tagName);\r\n $(\"#addTagForm\").submit();\r\n }\r\n });\r\n</script>\r\n\r\n<style type=\"text/css\">\r\n#new-resource-form tr td {\r\npadding-top: 0.5em;\r\n}\r\n#new-resource-form input:not([type=\"submit\"]) {\r\nfont-size: 0.8em;\r\n}\r\n#new-resource-form select {\r\nfont-size: 0.8em;\r\n}\r\n.new-resource-error {\r\nfont-size: 0.8em;\r\n}\r\n.resource-locale {\r\ncolor: #666;\r\nfont-family: Consolas, \"Andale Mono WT\", \"Andale Mono\", \"Lucida Console\", \"Lucida Sans Typewriter\", \"DejaVu Sans Mono\", \"Bitstream Vera Sans Mono\", \"Liberation Mono\", \"Nimbus Mono L\", Monaco, \"Courier New\", Courier, monospace;\r\n}\r\n</style>\r\n<div class=\"roundbox sidebox sidebar-menu borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Contest materials\n<div class=\"top-links\">\n</div>\n</div>\n<ul>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/10512\" title=\"Codeforces Round #226 (Div. 2)\" target=\"_blank\">Announcement</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"2193:2194\" resourceName=\"Announcement\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/10514\" title=\"Codeforces Round #226 (Div. 2) — Editorial\" target=\"_blank\">Tutorial</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"2197:2198\" resourceName=\"Tutorial\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n</ul>\r\n</div></div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li class=\"current selectedLava\"><a\r\n href=\"/contest/385\">Problems</a></li>\r\n <li><a\r\n href=\"/contest/385/submit\">Submit Code</a></li>\r\n <li><a\r\n href=\"/contest/385/my\">My Submissions</a></li>\r\n <li><a\r\n href=\"/contest/385/status\">Status</a></li>\r\n <li><a\r\n href=\"/contest/385/hacks\">Hacks</a></li>\r\n <li><a\r\n href=\"/contest/385/room/1\">Room</a></li>\r\n <li><a\r\n href=\"/contest/385/standings\">Standings</a></li>\r\n <li><a\r\n href=\"/contest/385/customtest\">Custom Invocation</a></li>\r\n</ul>\r\n</div>\n\r\n <style>\r\n #facebox .content:has(.diff-popup) {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n }\r\n\r\n .testCaseMarker {\r\n position: absolute;\r\n font-weight: bold;\r\n font-size: 1rem;\r\n }\r\n\r\n .diff-popup {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n display: none;\r\n overflow: auto;\r\n }\r\n\r\n .input-output-copier {\r\n font-size: 1.2rem;\r\n float: right;\r\n color: #888 !important;\r\n cursor: pointer;\r\n border: 1px solid rgb(185, 185, 185);\r\n padding: 3px;\r\n margin: 1px;\r\n line-height: 1.1rem;\r\n text-transform: none;\r\n }\r\n\r\n .input-output-copier:hover {\r\n background-color: #def;\r\n }\r\n\r\n .test-explanation textarea {\r\n width: 100%;\r\n height: 1.5em;\r\n }\r\n\r\n .pending-submission-message {\r\n color: darkorange !important;\r\n }\r\n </style>\r\n <script>\r\n const OPENING_SPACE = String.fromCharCode(1001);\r\n const CLOSING_SPACE = String.fromCharCode(1002);\r\n\r\n const nodeToText = function (node, pre) {\r\n let result = [];\r\n\r\n if (node.tagName === \"SCRIPT\" || node.tagName === \"math\"\r\n || (node.classList && node.classList.contains(\"input-output-copier\")))\r\n return [];\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(OPENING_SPACE);\r\n }\r\n\r\n if (node.nodeType === Node.TEXT_NODE) {\r\n let s = node.textContent;\r\n if (!pre) {\r\n s = s.replace(/\\s+/g, \" \");\r\n }\r\n if (s.length > 0) {\r\n result.push(s);\r\n }\r\n }\r\n\r\n if (pre && node.tagName === \"BR\") {\r\n result.push(\"\\n\");\r\n }\r\n\r\n node.childNodes.forEach(function (child) {\r\n result.push(nodeToText(child, node.tagName === \"PRE\").join(\"\"));\r\n });\r\n\r\n if (node.tagName === \"DIV\"\r\n || node.tagName === \"P\"\r\n || node.tagName === \"PRE\"\r\n || node.tagName === \"UL\"\r\n || node.tagName === \"LI\"\r\n ) {\r\n result.push(\"\\n\");\r\n }\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(CLOSING_SPACE);\r\n }\r\n\r\n return result;\r\n }\r\n\r\n const isSpecial = function (c) {\r\n return c === ',' || c === '.' || c === ';' || c === ')' || c === ' ';\r\n }\r\n\r\n const convertStatementToText = function(statmentNode) {\r\n const text = nodeToText(statmentNode, false).join(\"\").replace(/ +/g, \" \").replace(/\\n\\n+/g, \"\\n\\n\");\r\n let result = [];\r\n for (let i = 0; i < text.length; i++) {\r\n const c = text.charAt(i);\r\n if (c === OPENING_SPACE) {\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"A\" data-uuid=\"ps_04c9211edee0aa5967918380e93a1f0bbb99c26b\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">A. Bear and Raspberry</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>The bear decided to store some raspberry for the winter. He cunningly found out the price for a barrel of honey in kilos of raspberry for each of the following <span class=\"tex-span\"><i>n</i></span> days. According to the bear's data, on the <span class=\"tex-span\"><i>i</i></span>-th <span class=\"tex-span\">(1 ≤ <i>i</i> ≤ <i>n</i>)</span> day, the price for one barrel of honey is going to is <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span> kilos of raspberry.</p><p>Unfortunately, the bear has neither a honey barrel, nor the raspberry. At the same time, the bear's got a friend who is ready to lend him a barrel of honey for exactly one day for <span class=\"tex-span\"><i>c</i></span> kilograms of raspberry. That's why the bear came up with a smart plan. He wants to choose some day <span class=\"tex-span\"><i>d</i></span> <span class=\"tex-span\">(1 ≤ <i>d</i> < <i>n</i>)</span>, lent a barrel of honey and immediately (on day <span class=\"tex-span\"><i>d</i></span>) sell it according to a daily exchange rate. The next day <span class=\"tex-span\">(<i>d</i> + 1)</span> the bear wants to buy a new barrel of honey according to a daily exchange rate (as he's got some raspberry left from selling the previous barrel) and immediately (on day <span class=\"tex-span\"><i>d</i> + 1</span>) give his friend the borrowed barrel of honey as well as <span class=\"tex-span\"><i>c</i></span> kilograms of raspberry for renting the barrel.</p><p>The bear wants to execute his plan at most once and then hibernate. What maximum number of kilograms of raspberry can he earn? Note that if at some point of the plan the bear runs out of the raspberry, then he won't execute such a plan.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains two space-separated integers, <span class=\"tex-span\"><i>n</i></span> and <span class=\"tex-span\"><i>c</i></span> <span class=\"tex-span\">(2 ≤ <i>n</i> ≤ 100, 0 ≤ <i>c</i> ≤ 100)</span>, — the number of days and the number of kilos of raspberry that the bear should give for borrowing the barrel.</p><p>The second line contains <span class=\"tex-span\"><i>n</i></span> space-separated integers <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">1</sub>, <i>x</i><sub class=\"lower-index\">2</sub>, ..., <i>x</i><sub class=\"lower-index\"><i>n</i></sub></span> <span class=\"tex-span\">(0 ≤ <i>x</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 100)</span>, the price of a honey barrel on day <span class=\"tex-span\"><i>i</i></span>.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print a single integer — the answer to the problem.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>5 1<br />5 10 7 3 20<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>3<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>6 2<br />100 1 10 40 10 40<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>97<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3 0<br />1 2 3<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>0<br /></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>In the first sample the bear will lend a honey barrel at day 3 and then sell it for 7. Then the bear will buy a barrel for 3 and return it to the friend. So, the profit is (7 - 3 - 1) = 3.</p><p>In the second sample bear will lend a honey barrel at day 1 and then sell it for 100. Then the bear buy the barrel for 1 at the day 2. So, the profit is (100 - 1 - 2) = 97.</p></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=A]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== statementText) {\r\n $problem.find(\".diff-notifier\").show();\r\n\r\n $problem.find(\".diff-notifier-close\").click(function() {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n $problem.find(\".diff-notifier\").hide();\r\n });\r\n\r\n $problem.find(\"a.view-changes\").click(function() {\r\n $.post(\"/data/diff\", {action: \"getDiff\", a: previousStatementText, b: statementText}, function (result) {\r\n if (result[\"success\"] === \"true\") {\r\n Codeforces.facebox(\".diff-popup\", \"//codeforces.org/s/73366\");\r\n $(\"#facebox .diff-popup\").html(result[\"diff\"]);\r\n }\r\n }, \"json\");\r\n });\r\n }\r\n } else {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n }\r\n });\r\n });\r\n </script>\r\n\r\n\r\n<script type=\"text/javascript\">\r\n $(document).ready(function () {\r\n window.changedTests = new Set();\r\n\r\n function endsWith(string, suffix) {\r\n return string.indexOf(suffix, string.length - suffix.length) !== -1;\r\n }\r\n\r\n const inputFileDiv = $(\"div.input-file\");\r\n const inputFile = inputFileDiv.text();\r\n const outputFileDiv = $(\"div.output-file\");\r\n const outputFile = outputFileDiv.text();\r\n\r\n\r\n if (!endsWith(inputFile, \"standard input\")\r\n && !endsWith(inputFile, \"standard input\")) {\r\n inputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n if (!endsWith(outputFile, \"standard output\")\r\n && !endsWith(outputFile, \"standard output\")) {\r\n outputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n const titleDiv = $(\"div.header div.title\");\r\n\r\n\r\n\r\n String.prototype.replaceAll = function (search, replace) {\r\n return this.split(search).join(replace);\r\n };\r\n\r\n $(\".sample-test .title\").each(function () {\r\n const preId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n const cpyId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n\r\n $(this).parent().find(\"pre\").attr(\"id\", preId);\r\n const $copy = $(\"<div title='Copy' data-clipboard-target='#\" + preId + \"' id='\" + cpyId + \"' class='input-output-copier'>Copy</div>\");\r\n $(this).append($copy);\r\n\r\n const clipboard = new Clipboard('#' + cpyId, {\r\n text: function (trigger) {\r\n const pre = document.querySelector('#' + preId);\r\n const lines = pre.querySelectorAll(\".test-example-line\");\r\n return Codeforces.filterClipboardText(pre.innerText, lines.length);\r\n }\r\n });\r\n\r\n const isInput = $(this).parent().hasClass(\"input\");\r\n\r\n clipboard.on('success', function (e) {\r\n if (isInput) {\r\n Codeforces.showMessage(\"The example input has been copied into the clipboard\");\r\n } else {\r\n Codeforces.showMessage(\"The example output has been copied into the clipboard\");\r\n }\r\n e.clearSelection();\r\n });\r\n });\r\n\r\n $(\".test-form-item input\").change(function () {\r\n addPendingSubmissionMessage($($(this).closest(\"form\")), \"You changed the answer, do not forget to submit it if you want to save the changes\");\r\n const index = $(this).closest(\".problemindexholder\").attr(\"problemindex\");\r\n let test = \"\";\r\n $(this).closest(\"form input\").each(function () {\r\n const test_ = $(this).attr(\"name\");\r\n if (test_ && test_.substring(0, 4) === \"test\") {\r\n test = test_;\r\n }\r\n });\r\n if (index.length > 0 && test.length > 0) {\r\n const indexTest = index + \"::\" + test;\r\n window.changedTests.add(indexTest);\r\n }\r\n });\r\n\r\n $(window).on('beforeunload', function () {\r\n if (window.changedTests.size > 0) {\r\n return 'Dialog text here';\r\n }\r\n });\r\n\r\n autosize($('.test-explanation textarea'));\r\n\r\n $(\".test-example-line\").hover(function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n let top = 1E20;\r\n let left = 1E20;\r\n let problem = $(this).closest(\".problemindexholder\");\r\n $(this).closest(\".input\").find(\".\" + clazz).css(\"background-color\", \"#FFFDE7\").each(function() {\r\n top = Math.min(top, $(this).offset().top);\r\n left = Math.min(left, $(this).offset().left);\r\n });\r\n let testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n if (testCaseMarker.length === 0) {\r\n const html = \"<div class=\\\"testCaseMarker testCaseMarker_\" + end + \" notice\\\"></div>\";\r\n problem.append($(html));\r\n testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n }\r\n if (testCaseMarker) {\r\n testCaseMarker.show()\r\n .offset({top, left: left - 20})\r\n .text(end);\r\n }\r\n }\r\n }\r\n });\r\n }, function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n $(\".\" + clazz).css(\"background-color\", \"\");\r\n $(this).closest(\".problemindexholder\").find(\".testCaseMarker_\" + end).hide();\r\n }\r\n }\r\n });\r\n });\r\n\r\n });\r\n</script>\r\n\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 05:38:10</span> (j3).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/73366/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/73366/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/73366/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/73366/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-73366.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'8122c43409a23374',t:'MTY5NjY0NjI5MC43MzUwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"},"long_tags":{"kind":"string","value":"[\"Brute force\", \"Greedy algorithms\", \"Implementation problems, programming technics, simulation\"]"},"short_tags":{"kind":"string","value":"[\"brute force\", \"greedy\", \"implementation\", \"*1000\"]"},"tutorial_link":{"kind":"string","value":"https://codeforces.com/blog/entry/10514"},"tutorial_page":{"kind":"string","value":"\r\n\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"b0edd04b6e615eea61c4a67daabca579\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"h1\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Codeforces Round #226 (Div. 2) — Editorial - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n \n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Codeforces Round #226 (Div. 2) — Editorial - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/81027/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/81027/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/81027/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/81027/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/81027/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/81027/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/81027/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/81027/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/81027/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/81027/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/81027/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/81027/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/81027/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/81027/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/573cedc6b04c15481941f418269f4057/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='b0edd04b6e615eea61c4a67daabca579'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/81027/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fblog%2Fentry%2F10514\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='b0edd04b6e615eea61c4a67daabca579'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Pay attention\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n <div style=\"text-align:center;border-bottom: 1px solid rgb(185, 185, 185);margin:0 -0.5em 0.5em -0.5em;padding: 0 1em 0.5em 1em;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 1, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:51:56</span><br/><a href=\"/contestRegistration/1876\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n <div style=\"text-align:center;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 2, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:51:56</span><br/><a href=\"/contestRegistration/1877\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='b0edd04b6e615eea61c4a67daabca579'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n </label>\r\n </div>\r\n <div style=\"padding: 0 1em 1em 1em;text-align:right;\">\r\n <input style=\"height:1.65em;padding:0 0.75em;\" type=\"submit\" value=\"Find\"/>\r\n </div>\r\n </form>\r\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".handleBox\").autocomplete(\"/data/handles\", {\r\n delay: 200,\r\n width: 200,\r\n selectFirst: false,\r\n matchContains: true,\r\n minChars: 3\r\n });\r\n $(\".handleForm\").attr(\"autocomplete\", \"off\").submit(function () {\r\n var link = \"/profile/userHandle\".replace(\r\n \"userHandle\", $(this).find(\".handleBox\").val()\r\n );\r\n window.location = link;\r\n return false;\r\n });\r\n });\n </script>\n\r\n\r\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Recent actions\n <div class=\"top-links\">\n </div>\n </div>\n <div class=\"recent-actions\">\r\n <ul>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/121073\">Meta Hacker Cup 2023 Round 1</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/.Danet\" title=\"Expert .Danet\" class=\"rated-user user-blue\">.Danet</a> →\r\n <a href=\"/blog/entry/121172\">[TLE on pretest1]</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\" class=\"rated-user user-red\">Pyqe</a> →\r\n <a href=\"/blog/entry/121025\">Codeforces Round #902 (Div. 1, Div. 2, based on COMPFEST 15 — Final Round)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pranshu_Pandya\" title=\"Specialist Pranshu_Pandya\" class=\"rated-user user-cyan\">Pranshu_Pandya</a> →\r\n <a href=\"/blog/entry/121171\">An Interesting Tree Problem</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/sszcdjr\" title=\"Master sszcdjr\" class=\"rated-user user-orange\">sszcdjr</a> →\r\n <a href=\"/blog/entry/119859\">Codeforces Round 896 (Div. 1, Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/119880\">It's Happening! Meta Hacker Cup 2023 Schedule</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/DaviddeGea1\" title=\"Expert DaviddeGea1\" class=\"rated-user user-blue\">DaviddeGea1</a> →\r\n <a href=\"/blog/entry/70917\">Number of ways of dividing an array into 2 parts such that sum of each part is > k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bekh\" title=\"Master Bekh\" class=\"rated-user user-orange\">Bekh</a> →\r\n <a href=\"/blog/entry/74245\">Questions and doubts regarding Aliens DP trick</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a> →\r\n <a href=\"/blog/entry/8192\">Codeforces Round #190 — Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/hocky\" title=\"Candidate Master hocky\" class=\"rated-user user-violet\">hocky</a> →\r\n <a href=\"/blog/entry/95323\">FBHC wuining uw Day? Incwease uw stacc size! (ㅅ´ ˘ `)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/liouzhou_101\" title=\"International Master liouzhou_101\" class=\"rated-user user-orange\">liouzhou_101</a> →\r\n <a href=\"/blog/entry/87598\">Editorial of Codeforces Round #700</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/yeon_gist\" title=\"Newbie yeon_gist\" class=\"rated-user user-gray\">yeon_gist</a> →\r\n <a href=\"/blog/entry/121170\">plusMinusPermutation computing error</a>\r\n <img alt=\"Text created or updated\" title=\"Text created or updated\" src=\"//codeforces.org/s/81027/images/icons/x-update-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/altforminuscontribution\" title=\"Newbie altforminuscontribution\" class=\"rated-user user-gray\">altforminuscontribution</a> →\r\n <a href=\"/blog/entry/121162\">My screen get unexpectedly big, what should I do</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/atcoder_official\" title=\"Unrated, atcoder_official\" class=\"rated-user user-black\">atcoder_official</a> →\r\n <a href=\"/blog/entry/121120\">We will hold UNIQUE VISION Programming Contest 2023 Autumn(AtCoder Beginner Contest 323)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/YouStill_DontKnowMeYet\" title=\"Candidate Master YouStill_DontKnowMeYet\" class=\"rated-user user-violet\">YouStill_DontKnowMeYet</a> →\r\n <a href=\"/blog/entry/117659\">[GYM] Al-Baath Collegiate Programming Contest 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/ankancool\" title=\"Expert ankancool\" class=\"rated-user user-blue\">ankancool</a> →\r\n <a href=\"/blog/entry/121136\">Invitation to AstroByte 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/GeZhiyuan\" title=\"Grandmaster GeZhiyuan\" class=\"rated-user user-red\">GeZhiyuan</a> →\r\n <a href=\"/blog/entry/120943\">Codeforces Round 901 (Div. 1, Div. 2) Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a> →\r\n <a href=\"/blog/entry/120772\">PSA: Increase your stack size before the Meta Hacker Cup, here's how</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/dino_merlin\" title=\"Expert dino_merlin\" class=\"rated-user user-blue\">dino_merlin</a> →\r\n <a href=\"/blog/entry/121145\">Intuitive approach for CEOI Kangaroo?</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/icecuber\" title=\"Grandmaster icecuber\" class=\"rated-user user-red\">icecuber</a> →\r\n <a href=\"/blog/entry/70018\">CSES DP section editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bn00b\" title=\"Newbie Bn00b\" class=\"rated-user user-gray\">Bn00b</a> →\r\n <a href=\"/blog/entry/98820\">[FEATURE REQUEST : ATCODER] TOPICS TAGS AND SORTING BY SOLVE COUNT</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a> →\r\n <a href=\"/blog/entry/121163\">AtCoder Regular Contest 166 Announcement</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/windva\" title=\"Grandmaster windva\" class=\"rated-user user-red\">windva</a> →\r\n <a href=\"/blog/entry/120644\">Codeforces Round 899 (Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Misa-Misa\" title=\"Expert Misa-Misa\" class=\"rated-user user-blue\">Misa-Misa</a> →\r\n <a href=\"/blog/entry/121157\">Someone please help me understand this.</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/shivam565\" title=\"Specialist shivam565\" class=\"rated-user user-cyan\">shivam565</a> →\r\n <a href=\"/blog/entry/108348\">Total number of subarrays with sum atmost k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n </ul>\r\n </div>\r\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/recent-actions\">Detailed →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n</div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li><a\r\n href=\"/profile/CleRIC\">CleRIC</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/CleRIC\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/CleRIC\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/CleRIC\">Submissions</a></li>\r\n <li><a\r\n href=\"/groups/with/CleRIC\">Groups</a></li>\r\n <li><a\r\n href=\"/contests/with/CleRIC\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/CleRIC\">Problemsetting</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/CleRIC\" style=\"text-decoration:none;color:black !important;\">CleRIC's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"10569\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/10514\"> <p>Codeforces Round #226 (Div. 2) — Editorial</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/CleRIC\" title=\"Candidate Master CleRIC\" class=\"rated-user user-violet\">CleRIC</a>,\r\n <span class=\"format-humantime\" title=\"Jan/23/2014 19:33\">10 years ago</span>,\r\n translation,\r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p><a href=\"/contest/385/problem/A\" title=\"Codeforces Round 226 (Div. 2)\">385A - Bear and Raspberry</a></p><p>In this task required to understand that the answer max(<span class=\"tex-span\"><i>a</i>[<i>i</i>] - <i>a</i>[<i>i</i> - 1] - <i>c</i></span>),<span class=\"tex-span\"><i>i</i></span> = <span class=\"tex-span\">2..<i>n</i></span> and don't forget that the answer not negative as Bear can not borrow in the debt barrel of honey.</p><p><a href=\"/contest/385/problem/B\" title=\"Codeforces Round 226 (Div. 2)\">385B - Bear and Strings</a></p><p>In this problem you could write a better solution than the naive. To do this, you can iterate through the first cycle of the left index <span class=\"tex-span\"><i>l</i></span> considered substring and the second cycle of the right index <span class=\"tex-span\"><i>r</i></span> considered substring <span class=\"tex-span\">(<i>l</i> ≤ <i>r</i>)</span>. If any position has been substring "bear", means all the strings <span class=\"tex-span\"><i>x</i>(<i>l</i>, <i>j</i>)</span> <span class=\"tex-span\">(<i>i</i> ≤ <i>j</i>)</span>, also contain "bear" as a substring. So we can add to the answer <span class=\"tex-span\">|<i>s</i>| - <i>j</i> + 1</span> and exit from the second cycle. Also needed to understand, that if the string <span class=\"tex-span\"><i>x</i>(<i>l</i>, <i>j</i>)</span> was not a substring "bear", then in row <span class=\"tex-span\"><i>x</i>(<i>l</i>, <i>j</i> + 1)</span> substring "bear" could appear only in the last four characters.</p><p><a href=\"/contest/385/problem/C\" title=\"Codeforces Round 226 (Div. 2)\">385C - Bear and Prime Numbers</a></p><p>In order to solve given problem, contestant should solve several subproblems :</p><p>1) First one is to compute amount of entries of each natural number between <span class=\"tex-span\">2</span> and <span class=\"tex-span\">10<sup class=\"upper-index\">7</sup></span> in given list. This subproblem can be solved by creating array <span class=\"tex-span\"><i>count</i></span> of <span class=\"tex-span\">10<sup class=\"upper-index\">7</sup></span> elements and increasing corresponding element when scanning input.</p><p>2) Second one is to compute <span class=\"tex-span\"><i>f</i>(<i>n</i>)</span>.</p><p>First of all, we need to find all primes less than <span class=\"tex-span\">10<sup class=\"upper-index\">7</sup></span> and then for each prime <span class=\"tex-span\"><i>n</i></span> compute <span class=\"tex-span\"><i>f</i>(<i>n</i>)</span>.</p><p>How to compute <span class=\"tex-span\"><i>f</i>(2)</span>? We should sum <span class=\"tex-span\"><i>count</i>[2]</span>,<span class=\"tex-span\"><i>count</i>[4]</span>,<span class=\"tex-span\"><i>count</i>[6]</span>,<span class=\"tex-span\"><i>count</i>[8]</span>,...</p><p>How to compute <span class=\"tex-span\"><i>f</i>(5)</span>? We should sum <span class=\"tex-span\"><i>count</i>[5]</span>,<span class=\"tex-span\"><i>count</i>[10]</span>,<span class=\"tex-span\"><i>count</i>[15]</span>,<span class=\"tex-span\"><i>count</i>[20]</span>,...</p><p>How to compute <span class=\"tex-span\"><i>f</i>(<i>n</i>)</span>? We should sum <span class=\"tex-span\"><i>count</i>[<i>n</i>]</span>,<span class=\"tex-span\"><i>count</i>[2·<i>n</i>]</span>,<span class=\"tex-span\"><i>count</i>[3·<i>n</i>]</span>,<span class=\"tex-span\"><i>count</i>[4·<i>n</i>]</span>,...</p><p>It can be seen that given algo is very similar to Sieve of Eratosthenes. (Info here <a href=\"http://e-maxx.ru/algo/eratosthenes_sieve\">http://e-maxx.ru/algo/eratosthenes_sieve</a>) So we can use this algo if we change it a little bit. Also, we will store results of calculation in array, e.g. <span class=\"tex-span\"><i>pre</i></span>. Namely, <span class=\"tex-span\"><i>pre</i>[<i>n</i>]</span> = <span class=\"tex-span\"><i>f</i>(<i>n</i>)</span>.</p><p>3) Now we can calculate partial sums of <span class=\"tex-span\"><i>pre</i></span> array. It can be made in a single pass just adding <span class=\"tex-span\"><i>pre</i>[<i>i</i> - 1]</span> to <span class=\"tex-span\"><i>pre</i>[<i>i</i>]</span>.</p><p>4) If we know partial sums of array then we can calculate sum of array elements between <span class=\"tex-span\"><i>l</i></span> and <span class=\"tex-span\"><i>r</i></span> in time proportional <span class=\"tex-span\"><i>O</i>(1)</span>, just calculate <span class=\"tex-span\"><i>pre</i>[<i>r</i>] - <i>pre</i>[<i>l</i> - 1]</span>.</p><p>5) Now we can read queries and immediately response to them. You shouldn't forget that right boundaries of intervals can be greater than <span class=\"tex-span\">10<sup class=\"upper-index\">7</sup></span>, so you can always decrease it to <span class=\"tex-span\">10<sup class=\"upper-index\">7</sup></span>, because all numbers in given list are less than <span class=\"tex-span\">10<sup class=\"upper-index\">7</sup></span>.</p><p><a href=\"/contest/385/problem/D\" title=\"Codeforces Round 226 (Div. 2)\">385D - Bear and Floodlight</a></p><p>In this task, it is crucial to understand that whether there is lighted part of road with length <span class=\"tex-span\"><i>dist</i></span> then next part should be lit in a such way that leftmost lighted point is touching with <span class=\"tex-span\"><i>dist</i></span>.</p><p>Let's suppose that road is lit from <span class=\"tex-span\"><i>l</i></span> to <span class=\"tex-span\"><i>d</i></span>. How we can find rightmost point on X axis that would be lit by next floodlight?</p><p>We can just use concepts of vector and rotation matrix.</p><p>Let's find vector <span class=\"tex-span\">(<i>dx</i>, <i>dy</i>)</span> from floodlight to point on X axis <span class=\"tex-span\">(<i>d</i>, 0)</span>. <span class=\"tex-span\">(<i>dx</i>, <i>dy</i>)</span> = <span class=\"tex-span\">(<i>d</i> - <i>x</i>, 0 - <i>y</i>)</span>.</p><p>Next point to rotate vector by <span class=\"tex-span\"><i>angle</i></span> degrees. We can use rotation matrix for this purpose.</p><p><span class=\"tex-span\">(<i>dx</i>, <i>dy</i>)</span> = <span class=\"tex-span\">(<i>dx</i>·<i>cos</i>(<i>angle</i>) - <i>dy</i>·<i>sin</i>(<i>angle</i>), <i>dx</i>·<i>sin</i>(<i>angle</i>) + <i>dy</i>·<i>cos</i>(<i>angle</i>))</span></p><p>Next, we should make second component <span class=\"tex-span\"><i>dy</i></span> of <span class=\"tex-span\">(<i>dx</i>, <i>dy</i>)</span> equal to <span class=\"tex-span\">1</span> by multiplying on coefficient <span class=\"tex-span\"><i>k</i></span>.</p><p>Now we can determine rightmost lighted point of X axis. It is <span class=\"tex-span\"><i>x</i> - <i>y</i>·<i>dx</i></span>.</p><p>You shouldn't forget that there is possibility for rightmost point to be infinitely far point.</p><p>From now on we can forget about geometry in this task.</p><p>Let's find fast way to determine optimal order of floodlights.</p><p>To achieve this goal, we can use dynamic programming approach. Namely, let's calculate answer for subsets of floodlights. Each subset would be represented as integer where <span class=\"tex-span\"><i>k</i></span> bit would be <span class=\"tex-span\">1</span> if <span class=\"tex-span\"><i>k</i></span> floodlight is presented in subset and <span class=\"tex-span\">0</span> if it is not, i.e. so named binary mask.</p><p>For example, <span class=\"tex-span\"><i>dp</i>[6]</span> — (<span class=\"tex-span\">6</span> — <span class=\"tex-span\">110<sub class=\"lower-index\">2</sub></span>) is optimal answer for subset from <span class=\"tex-span\">2</span> and <span class=\"tex-span\">3</span> floodlight.</p><p>Now, let's look through subsets <span class=\"tex-span\"><i>i</i></span> in <span class=\"tex-span\"><i>dp</i>[<i>i</i>]</span>. In subset <span class=\"tex-span\"><i>i</i></span> let's go through absent floodlights <span class=\"tex-span\"><i>j</i></span> and update result for subset where <span class=\"tex-span\"><i>j</i></span> floodlight is present, i.e. dp[ <span class=\"tex-span\"><i>i</i></span> or <span class=\"tex-span\">2<sup class=\"upper-index\"><i>j</i></sup></span> ] = max(dp[ <span class=\"tex-span\"><i>i</i></span> or <span class=\"tex-span\">2<sup class=\"upper-index\"><i>j</i></sup></span>], dp[ <span class=\"tex-span\"><i>i</i></span> ] + calc_rightmost_lighted_point() ). As we can calculate rightmost lighted point, so updating of answer shouldn't be a problem.</p><p><a href=\"/contest/385/problem/E\" title=\"Codeforces Round 226 (Div. 2)\">385E - Bear in the Field</a></p><p>In this task there are several problems that should be concerned:</p><p>1) Simple modeling of bear movement would cause TLE due to <span class=\"tex-span\"><i>t</i></span> <span class=\"tex-span\"> ≤ </span> <span class=\"tex-span\">10<sup class=\"upper-index\">18</sup></span>.</p><p>2) Task can't be solved by separating <span class=\"tex-span\"><i>x</i></span> and <span class=\"tex-span\"><i>y</i></span> axes because <span class=\"tex-span\"><i>x</i></span> and <span class=\"tex-span\"><i>y</i></span> depends on each other.</p><p>3) Also, we can't use standart method of cycle finding via modeling for a short time and checking on collisions because coordinates limitations are very large.</p><p>Let's say we have matrix <span class=\"tex-span\">(<i>x</i><sub class=\"lower-index\"><i>i</i></sub>, <i>y</i><sub class=\"lower-index\"><i>i</i></sub>, <i>dx</i><sub class=\"lower-index\"><i>i</i></sub>, <i>dy</i><sub class=\"lower-index\"><i>i</i></sub>, <i>t</i><sub class=\"lower-index\"><i>i</i></sub>, 1)</span>.</p><p>If we multiply previous matrix by following matrix long long base[6][6] = {</p><p>{2,1,1,1,0,0},</p><p>{1,2,1,1,0,0},</p><p>{1,0,1,0,0,0},</p><p>{0,1,0,1,0,0},</p><p>{0,0,1,1,1,0},</p><p>{0,0,2,2,1,1} };</p><p>we will have get parameters on next step.</p><p>Where did the matrix? Let us write out how to change parameters with each step and see the similarity matrix.</p><p><span class=\"tex-span\"><i>x</i></span> = <span class=\"tex-span\">2·<i>x</i></span> + <span class=\"tex-span\">1·<i>y</i></span> + <span class=\"tex-span\">1·<i>dx</i></span> + <span class=\"tex-span\">0·<i>dy</i></span> + <span class=\"tex-span\">0·<i>t</i></span> + <span class=\"tex-span\">0·1</span>.</p><p><span class=\"tex-span\"><i>y</i></span> = <span class=\"tex-span\">1·<i>x</i></span> + <span class=\"tex-span\">2·<i>y</i></span> + <span class=\"tex-span\">0·<i>dx</i></span> + <span class=\"tex-span\">1·<i>dy</i></span> + <span class=\"tex-span\">0·<i>t</i></span> + <span class=\"tex-span\">0·1</span>.</p><p><span class=\"tex-span\"><i>dx</i></span> = <span class=\"tex-span\">1·<i>x</i></span> + <span class=\"tex-span\">1·<i>y</i></span> + <span class=\"tex-span\">1·<i>dx</i></span> + <span class=\"tex-span\">0·<i>dy</i></span> + <span class=\"tex-span\">1·<i>t</i></span> + <span class=\"tex-span\">2·1</span>.</p><p><span class=\"tex-span\"><i>dy</i></span> = <span class=\"tex-span\">1·<i>x</i></span> + <span class=\"tex-span\">1·<i>y</i></span> + <span class=\"tex-span\">0·<i>dx</i></span> + <span class=\"tex-span\">1·<i>dy</i></span> + <span class=\"tex-span\">1·<i>t</i></span> + <span class=\"tex-span\">2·1</span>.</p><p><span class=\"tex-span\"><i>t</i></span> = <span class=\"tex-span\">0·<i>x</i></span> + <span class=\"tex-span\">0·<i>y</i></span> + <span class=\"tex-span\">0·<i>dx</i></span> + <span class=\"tex-span\">0·<i>dy</i></span> + <span class=\"tex-span\">1·<i>t</i></span> + <span class=\"tex-span\">1·1</span>.</p><p><span class=\"tex-span\">1</span> = <span class=\"tex-span\">0·<i>x</i></span> + <span class=\"tex-span\">0·<i>y</i></span> + <span class=\"tex-span\">0·<i>dx</i></span> + <span class=\"tex-span\">0·<i>dy</i></span> + <span class=\"tex-span\">0·<i>t</i></span> + <span class=\"tex-span\">1·1</span>.</p><p>So if we calculate <span class=\"tex-span\"><i>t</i> - 1</span> power of <span class=\"tex-span\"><i>base</i></span> and then multiply <span class=\"tex-span\">(<i>sx</i>, <i>sy</i>, <i>dx</i>, <i>dy</i>, <i>t</i>, 1)</span> by it we will calculate parameters at moment <span class=\"tex-span\"><i>t</i></span>.</p><p>Power of matrix can be calculated via binary power modulo algo due to associativity of matrix multiplication. More info at <a href=\"http://e-maxx.ru/algo/binary_pow\">http://e-maxx.ru/algo/binary_pow</a></p><p>Using trivial matrix multiplication algo we will solve this task in time proportional <span class=\"tex-span\">6<sup class=\"upper-index\">3</sup>·<i>log</i>(<i>t</i>)</span>.</p></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/385\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 226 (Div. 2)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-2930-10569\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"2930\",\n blogEntryId: \"10514\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-10569\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+85</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-10569\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/CleRIC\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/CleRIC\">\n CleRIC\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Jan/23/2014 19:33\">10 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/10514#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/10514#comments\">\n 30\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"10585\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (25)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158988\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/OpalDshawn\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/40047/avatar/c26edf07c13c133a.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/OpalDshawn\" title=\"Master OpalDshawn\" class=\"rated-user user-orange\">OpalDshawn</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2014 22:59\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158988\" href=\"?#comment-158988\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"158988\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"158988\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"40047\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158988\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Great Editorial!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158988 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158988 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158988\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159026\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Xellos\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/69675/avatar/8526bcfc8e687b43.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/Xellos\" title=\"International Grandmaster Xellos\" class=\"rated-user user-red\">Xellos</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/25/2014 02:06\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159026\" href=\"?#comment-159026\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"159026\" revisionCount=\"7\" revision=\"7\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">7</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"159026\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"28\"\r\n data-commentUserId=\"69675\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+28</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159026\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I solved E (theoretically, I don't really want to implement it) by solving the system of equations:</p> <center><span class=\"tex-span\"><i>x</i>(<i>t</i>) = [<i>x</i>(<i>t</i> - 1) + <i>v</i><sub class=\"lower-index\"><i>x</i></sub>(<i>t</i>) - 1]%<i>N</i> + 1</span></center> <center><span class=\"tex-span\"><i>y</i>(<i>t</i>) = [<i>y</i>(<i>t</i> - 1) + <i>v</i><sub class=\"lower-index\"><i>y</i></sub>(<i>t</i>) - 1]%<i>N</i> + 1</span></center> <center><span class=\"tex-span\"><i>v</i><sub class=\"lower-index\"><i>x</i></sub>(<i>t</i>) = <i>v</i><sub class=\"lower-index\"><i>x</i></sub>(<i>t</i> - 1) + <i>t</i> - 1 + <i>x</i>(<i>t</i> - 1) + <i>y</i>(<i>t</i> - 1)</span></center> <center><span class=\"tex-span\"><i>v</i><sub class=\"lower-index\"><i>y</i></sub>(<i>t</i>) = <i>v</i><sub class=\"lower-index\"><i>y</i></sub>(<i>t</i> - 1) + <i>t</i> - 1 + <i>x</i>(<i>t</i> - 1) + <i>y</i>(<i>t</i> - 1)</span></center><p>for $t > 0$, where the values of <span class=\"tex-span\">(<i>x</i>, <i>y</i>, <i>v</i><sub class=\"lower-index\"><i>x</i></sub>, <i>v</i><sub class=\"lower-index\"><i>y</i></sub>)(0)</span> are given as input parameters, and the time is 0-based.</p><p>Firstly, we want to get rid of the modulo function. We can't just compute all variables modulo <span class=\"tex-span\"><i>N</i></span>, because there's the -1, so we'll shift the coordinates to <span class=\"tex-span\">(<i>x</i>', <i>y</i>')(<i>t</i>)</span>, where <span class=\"tex-span\"><i>x</i>' = <i>x</i> - 1</span>, <span class=\"tex-span\"><i>y</i>' = <i>y</i> - 1</span>. Now the equations become</p> <center><span class=\"tex-span\"><i>x</i>'(<i>t</i>) = <i>x</i>'(<i>t</i> - 1) + <i>v</i><sub class=\"lower-index\"><i>x</i></sub>(<i>t</i>)</span></center> <center><span class=\"tex-span\"><i>y</i>'(<i>t</i>) = <i>y</i>'(<i>t</i> - 1) + <i>v</i><sub class=\"lower-index\"><i>y</i></sub>(<i>t</i>)</span></center> <center><span class=\"tex-span\"><i>v</i><sub class=\"lower-index\"><i>x</i></sub>(<i>t</i>) = <i>v</i><sub class=\"lower-index\"><i>x</i></sub>(<i>t</i> - 1) + <i>t</i> + 1 + <i>x</i>'(<i>t</i> - 1) + <i>y</i>'(<i>t</i> - 1)</span></center> <center><span class=\"tex-span\"><i>v</i><sub class=\"lower-index\"><i>y</i></sub>(<i>t</i>) = <i>v</i><sub class=\"lower-index\"><i>y</i></sub>(<i>t</i> - 1) + <i>t</i> + 1 + <i>x</i>'(<i>t</i> - 1) + <i>y</i>'(<i>t</i> - 1)</span></center><p>where all variables are computed modulo $N$ (we'll omit that from now on). We can compute <span class=\"tex-span\">(<i>x</i>, <i>y</i>, <i>v</i><sub class=\"lower-index\"><i>x</i></sub>, <i>v</i><sub class=\"lower-index\"><i>y</i></sub>)(1)</span> from this, and further substitute for <span class=\"tex-span\"><i>v</i><sub class=\"lower-index\"><i>x</i></sub>, <i>v</i><sub class=\"lower-index\"><i>y</i></sub></span>, which gives for <span class=\"tex-span\"><i>t</i> > 1</span></p> <center><span class=\"tex-span\"><i>x</i>'(<i>t</i>) - <i>x</i>'(<i>t</i> - 1) = <i>x</i>'(<i>t</i> - 1) - <i>x</i>'(<i>t</i> - 2) + <i>t</i> + 1 + <i>x</i>'(<i>t</i> - 1) + <i>y</i>'(<i>t</i> - 1)</span></center> <center><span class=\"tex-span\"><i>y</i>'(<i>t</i>) - <i>y</i>'(<i>t</i> - 1) = <i>y</i>'(<i>t</i> - 1) - <i>y</i>'(<i>t</i> - 2) + <i>t</i> + 1 + <i>x</i>'(<i>t</i> - 1) + <i>y</i>'(<i>t</i> - 1)</span></center><p>Let's now define</p> <center><span class=\"tex-span\"><i>s</i>(<i>t</i>) = <i>x</i>'(<i>t</i>) + <i>y</i>'(<i>t</i>)</span></center> <center><span class=\"tex-span\"><i>d</i>(<i>t</i>) = <i>x</i>'(<i>t</i>) - <i>y</i>'(<i>t</i>)</span></center><p>using which we can rewrite the sum and difference of the equations above to</p> <center><span class=\"tex-span\"><i>d</i>(<i>t</i>) - <i>d</i>(<i>t</i> - 1) = <i>d</i>(<i>t</i> - 1) - <i>d</i>(<i>t</i> - 2)</span></center> <center><span class=\"tex-span\"><i>s</i>(<i>t</i>) - <i>s</i>(<i>t</i> - 1) = <i>s</i>(<i>t</i> - 1) - <i>s</i>(<i>t</i> - 2) + 2(<i>t</i> + 1) + 2<i>s</i>(<i>t</i> - 1)</span></center><p>Once again, we define $q(t)=s(t)+t+2$ (actually, it's <span class=\"tex-span\"><i>s</i>(<i>t</i>) + <i>t</i> + <i>c</i></span>, and we compute the constant <span class=\"tex-span\"><i>c</i></span> by substituting and trying to get the constant term to 0), and rewrite our equations to</p> <center><span class=\"tex-span\"><i>d</i>(<i>t</i>) = 2<i>d</i>(<i>t</i> - 1) - <i>d</i>(<i>t</i> - 2)</span></center> <center><span class=\"tex-span\"><i>q</i>(<i>t</i>) = 4<i>q</i>(<i>t</i> - 1) - <i>q</i>(<i>t</i> - 2)</span></center><p>which can be solved explicitly (I'm lazy, so I'm just using Wolfram Alpha, read more about linear recurrent equations on Wikipedia or something):</p> <center><img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/5ec2a1c8cb9dd5c6d22e9c89f85ea721c45a9659.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></center> <center><span class=\"tex-span\"><i>d</i>(<i>t</i>) = <i>C</i> * <i>t</i> + <i>D</i></span></center><p>where the parameters $A..D$ are given by the values for <span class=\"tex-span\"><i>t</i> ≤ 1</span>.</p><p>This is more of a theoretical solution (since as long as we get the recurrences for <span class=\"tex-span\"><i>d</i>(<i>t</i>)</span> and <span class=\"tex-span\"><i>q</i>(<i>t</i>)</span>, it's best to use matrix multiplication), but I just wanted to do it this way :D</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159026 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159026 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159026\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159027\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/bilalyasar\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/88216/avatar/25c063de47c0f66a.jpg'/> </a>\n <div><a href=\"/profile/bilalyasar\" title=\"Expert bilalyasar\" class=\"rated-user user-blue\">bilalyasar</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/25/2014 03:59\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159027\" href=\"?#comment-159027\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"159027\" revisionCount=\"23\" revision=\"23\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">23</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"159027\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"88216\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159027\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>i think the matrix should be that: {2,1,1,1,0,0},</p><p>{1,2,1,1,0,0},</p><p>{1,0,1,0,0,0},</p><p>{0,1,0,1,0,0},</p><p>{0,0,1,1,1,0},</p><p>{0,0,0,0,1,1} };</p><p>i tried and solved it. with this matrix.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159027 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159027 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159027\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159144\" commentParentId=\"159027\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Amir.bh\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/29435/avatar/84331c66da301d6d.jpg'/> </a>\n <div><a href=\"/profile/Amir.bh\" title=\"Candidate Master Amir.bh\" class=\"rated-user user-violet\">Amir.bh</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/26/2014 15:32\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159144\" href=\"?#comment-159144\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159027\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159144\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"29435\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159144\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Rev. 23????! How could this happen?! :D</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159144 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159144 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159144\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159162\" commentParentId=\"159144\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Xellos\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/69675/avatar/8526bcfc8e687b43.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/Xellos\" title=\"International Grandmaster Xellos\" class=\"rated-user user-red\">Xellos</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/26/2014 17:13\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159162\" href=\"?#comment-159162\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159144\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159162\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"69675\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159162\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Maybe for the same reason as rev.7 of my comment above — I edit my comment, click "Save", nothing happens; I wait until my internet connection is stronger, click again, and nothing happens again, etc., until I lose patience and reload the page. And look what happened: the revisions were counted, but my comment wasn't edited. Some bug of CF, maybe.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159162 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159162 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159162\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159054\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/llaki\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/24382/avatar/6683eebf7eea08ec.jpg'/> </a>\n <div><a href=\"/profile/llaki\" title=\"Expert llaki\" class=\"rated-user user-blue\">llaki</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/25/2014 15:18\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159054\" href=\"?#comment-159054\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159054\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"24382\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159054\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Nice editorial. Anyways, I had a sense that explanation of problem E does not give you an idea of how you can come up with that solution. Let me clarify that: The state can be described by following variables: x — where is the bear currently (x-coordinate); y — where is the bear currently (y-coordinate); dx — the current speed towards X axis; dy — the current speed towards Y axis; t — time passed after the start;</p><p>This information is enough to describe a state. Now let's see how the state changes: (dx)' = dx + (x+y+t), (dy)' = dy+(x+y+t), (x)' = x + (dx)' = 2x+y+dx+t, (y)'=x+2y+dy+t, (t)'= t+1.</p><p>As we see, the new state is similar to linear combination of previous state components, except for t=t+1 (1 is not in a state). It is very similar to matrix multiplication, except for we don't have 1. So we can make a matrix this way: Let's say the state is (1x6) matrix : (x, y, dx, dy, t, 1) and the matrix (M) is 100001 021110 012110 010100 001010 011111 It's easy to see why the new state is the old state matrix multiplied by M. The rest is easy, our final state is going to be the initial state matrix multiplied by the T-th power of M. Of course we're gonna use the fast exponentiation. (The naive multiplication is fine here, because the sizes are too small)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159054 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159054 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159054\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159061\" commentParentId=\"159054\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/KKpoker\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/120167/avatar/297c9d6f6c6672be.jpg'/> </a>\n <div><a href=\"/profile/KKpoker\" title=\"Specialist KKpoker\" class=\"rated-user user-cyan\">KKpoker</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/25/2014 16:34\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159061\" href=\"?#comment-159061\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159054\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"159061\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"159061\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"4\"\r\n data-commentUserId=\"120167\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+4</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159061\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>thx a lot ~ during the exam i think the raspberry will be eaten all , then the number will change from x+y-->1 a silly misunderstanding T_T</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159061 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159061 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159061\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"372356\" commentParentId=\"159054\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/nguyenit67\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/509284/avatar/98668c3aa6c04ca6.jpg'/> </a>\n <div><a href=\"/profile/nguyenit67\" title=\"Pupil nguyenit67\" class=\"rated-user user-green\">nguyenit67</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/11/2017 14:02\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-372356\" href=\"?#comment-372356\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159054\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"372356\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"509284\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-372356\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I'm sorry :) but I don't see why (x)'= x+(dx)'? Could u explain that to me?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-372356 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-372356 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-372356\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"372645\" commentParentId=\"372356\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/nguyenit67\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/509284/avatar/98668c3aa6c04ca6.jpg'/> </a>\n <div><a href=\"/profile/nguyenit67\" title=\"Pupil nguyenit67\" class=\"rated-user user-green\">nguyenit67</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/12/2017 08:25\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-372645\" href=\"?#comment-372645\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-372356\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"372645\" revisionCount=\"4\" revision=\"4\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">4</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"372645\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"509284\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-372645\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Ah</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-372645 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-372645 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-372645\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"372646\" commentParentId=\"159054\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/nguyenit67\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/509284/avatar/98668c3aa6c04ca6.jpg'/> </a>\n <div><a href=\"/profile/nguyenit67\" title=\"Pupil nguyenit67\" class=\"rated-user user-green\">nguyenit67</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/12/2017 08:26\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-372646\" href=\"?#comment-372646\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159054\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"372646\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"509284\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-372646\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Ah now I see it. Thank you for your explanation :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-372646 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-372646 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-372646\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159079\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/MoustafaMaher\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/47658/avatar/48ad52ec2bf89c75.jpg'/> </a>\n <div><a href=\"/profile/MoustafaMaher\" title=\"Candidate Master MoustafaMaher\" class=\"rated-user user-violet\">MoustafaMaher</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/25/2014 19:18\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159079\" href=\"?#comment-159079\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159079\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"47658\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159079\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Problem D !?! </p><p>how u can calculate calc_rightmost_lighted_point() in ur Dp without keeping the last right_most_point u can get till before this state </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159079 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159079 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159079\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159093\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Lord_F\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/41018/avatar/1e2b817ca83c107e.jpg'/> </a>\n <div><a href=\"/profile/Lord_F\" title=\"Candidate Master Lord_F\" class=\"rated-user user-violet\">Lord_F</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/25/2014 21:37\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159093\" href=\"?#comment-159093\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"159093\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"159093\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"41018\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159093\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>By the way, in problem D you can use law of sines to find the distance that is lighted with some floodlight.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159093 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159093 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159093\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159105\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/-emli-\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/29285/avatar/9fa3a36fa8f9d060.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/-emli-\" title=\"Pupil -emli-\" class=\"rated-user user-green\">-emli-</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/25/2014 23:59\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159105\" href=\"?#comment-159105\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159105\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"29285\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159105\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In problem C , i can't understand why we add pre[i-1] to pre[i]?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159105 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159105 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159105\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159109\" commentParentId=\"159105\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/piotreekw\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/piotreekw\" title=\"Specialist piotreekw\" class=\"rated-user user-cyan\">piotreekw</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/26/2014 00:51\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159109\" href=\"?#comment-159109\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159105\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159109\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"151924\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159109\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>If you iterate i from 2 to n-1 adding pre[i-1] to pre[i], every new pre[i] will contain sum of all pre from 1 to i</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159109 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159109 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159109\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159126\" commentParentId=\"159109\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/-emli-\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/29285/avatar/9fa3a36fa8f9d060.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/-emli-\" title=\"Pupil -emli-\" class=\"rated-user user-green\">-emli-</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/26/2014 09:24\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159126\" href=\"?#comment-159126\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159109\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159126\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"29285\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159126\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thank you! one more question how to prove that pre[r]-pre[l-1] is answer of query?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159126 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159126 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159126\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159129\" commentParentId=\"159126\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ReekinAcer\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/ReekinAcer\" title=\"Expert ReekinAcer\" class=\"rated-user user-blue\">ReekinAcer</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/26/2014 12:01\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159129\" href=\"?#comment-159129\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159126\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159129\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"106426\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159129\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I think it is clearer if we denote Cnt[i] = f(i) and Sum[i] = Cnt[1] + Cnt[2] + ... + Cnt[i]. Now, the answer for a query on [l, r] is Sum[r]-Sum[l-1].</p><p>Sum[r]-Sum[l-1] = (Cnt[1] + Cnt[2] + ... + Cnt[r])-(Cnt[1] + Cnt[2] + ... + Cnt[l-1]) = [(Cnt[1] + ... + Cnt[l-1]) + (Cnt[l] + Cnt[l + 1] + ... + Cnt[r])] — (Cnt[1] + ... + Cnt[l-1]) = Cnt[l] + Cnt[l + 1] + ... + Cnt[r].</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159129 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159129 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159129\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"211346\" commentParentId=\"159105\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/G_Hani\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/119692/avatar/ea9b44051a710c1b.jpg'/> </a>\n <div><a href=\"/profile/G_Hani\" title=\"Specialist G_Hani\" class=\"rated-user user-cyan\">G_Hani</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/06/2015 00:49\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-211346\" href=\"?#comment-211346\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159105\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"211346\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"119692\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-211346\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p><a class=\"rated-user user-green\" href=\"/profile/-emli-\" title=\"Pupil -emli-\">-emli-</a> <a class=\"rated-user user-blue\" href=\"/profile/ReekinAcer\" title=\"Expert ReekinAcer\">ReekinAcer</a> can u help me please. here my code for C and get WA at tc 4 !! <a href=\"/contest/385/submission/9731769\" title=\"Submission 9731769 by G_Hani\">9731769</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-211346 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-211346 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-211346\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159138\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/shubh09\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/shubh09\" title=\"Expert shubh09\" class=\"rated-user user-blue\">shubh09</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/26/2014 13:36\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159138\" href=\"?#comment-159138\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159138\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"72364\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159138\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Nice editorial! But I suppose that a link to a solution implementing the idea outlined in the editorial for every question would help us understand them even better!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159138 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159138 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159138\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159141\" commentParentId=\"159138\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Lord_F\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/41018/avatar/1e2b817ca83c107e.jpg'/> </a>\n <div><a href=\"/profile/Lord_F\" title=\"Candidate Master Lord_F\" class=\"rated-user user-violet\">Lord_F</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/26/2014 14:13\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159141\" href=\"?#comment-159141\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159138\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"159141\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"159141\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"41018\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159141\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Well, you can use "Status filter"</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159141 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159141 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159141\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159178\" commentParentId=\"159141\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/shubh09\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/shubh09\" title=\"Expert shubh09\" class=\"rated-user user-blue\">shubh09</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/26/2014 18:14\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159178\" href=\"?#comment-159178\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159141\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159178\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"72364\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159178\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Well, not all the accepted solutions use the idea mentioned in the editorials. It's a bit inconvenient browsing through all accepted solutions to find the one which does.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159178 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159178 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159178\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"330629\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/adityagupta1089\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/337877/avatar/e2156094910d501.jpg'/> </a>\n <div><a href=\"/profile/adityagupta1089\" title=\"Expert adityagupta1089\" class=\"rated-user user-blue\">adityagupta1089</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Dec/14/2016 22:58\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-330629\" href=\"?#comment-330629\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"330629\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"330629\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"337877\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-330629\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In problem C, I did made a cnt array (or say a hashmap) and did find all primes below the maximum x using Sieve of Erathosthenes, then for each prime I iterated over every number and and found f(p) and stored them in a Binary Index Tree, but that didn't help. I believe my complexity is O(n(logn)(loglogn)+m(logn+logP)+PlogP) where P(664,579~10^7) is the count of primes below maximum x so total operations are around 5e6+6e7+4e7 but it has a TLE?.<a href=\"//codeforces.com/contest/385/submission/22981801\">This</a> is my submission.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-330629 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-330629 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-330629\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"587392\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/reet_bhaati\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1176149/avatar/7f68facc9bda856e.jpg'/> </a>\n <div><a href=\"/profile/reet_bhaati\" title=\"Specialist reet_bhaati\" class=\"rated-user user-cyan\">reet_bhaati</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/10/2020 10:46\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-587392\" href=\"?#comment-587392\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"587392\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"-8\"\r\n data-commentUserId=\"1176149\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-587392\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>can anyone help me out? I have tried 385C and it gives me a runtime error on test case 4 link to my code — <a href=\"https://ideone.com/fork/GMagWh\">https://ideone.com/fork/GMagWh</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-587392 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-587392 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-587392\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"642670\" commentParentId=\"587392\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/back_to_code\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1292092/avatar/b57b403a9af2ef26.jpg'/> </a>\n <div><a href=\"/profile/back_to_code\" title=\"Specialist back_to_code\" class=\"rated-user user-cyan\">back_to_code</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/15/2020 21:38\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-642670\" href=\"?#comment-642670\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-587392\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"642670\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"642670\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1292092\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-642670\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I don't know if you are still looking for this :</p><p>That might be because x or y i.e the query ranges might be going out of limits. Also it may help the others who attempt it.</p><p>Edit : Also if anyone is getting TLE even after implementing same approach use:</p> <pre><code>ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);\n</code></pre></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-642670 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-642670 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-642670\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"658423\" commentParentId=\"587392\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/apoorva222g\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1213778/avatar/2153e9cce1fd37f.jpg'/> </a>\n <div><a href=\"/profile/apoorva222g\" title=\"Expert apoorva222g\" class=\"rated-user user-blue\">apoorva222g</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/09/2020 11:58\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-658423\" href=\"?#comment-658423\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-587392\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"658423\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1213778\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-658423\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Reduce any l or r to 10^7 if it is greater than 10^7. Try this case 1 2000 1 1424767024 1629755604</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-658423 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-658423 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-658423\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"686007\" commentParentId=\"658423\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/y0g38h_kum4r\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1561883/avatar/5594dfbdb87a226d.jpg'/> </a>\n <div><a href=\"/profile/y0g38h_kum4r\" title=\"Expert y0g38h_kum4r\" class=\"rated-user user-blue\">y0g38h_kum4r</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/25/2020 02:40\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-686007\" href=\"?#comment-686007\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-658423\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"686007\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1561883\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-686007\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>OH! thanks a lot for this test case!!!!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-686007 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-686007 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-686007\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n <br/>\r\n\r\n<div id=\"editBox-10585\" style=\"width:50em;display:none;\">\r\n <div class=\"previewBody\" style=\"border: 1px solid #d4d4d4; margin-bottom: 0.5em; padding: 0.25em; display:none;\"> </div>\r\n <div style=\"width: 1px\"> </div>\r\n <div class=\"commentLocale\" style=\"position: relative; top: 0.5em;left:4px;display: none;\">\r\n <input type=\"radio\" name=\"locale\" value=\"en\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In English</span>\r\n <input style=\"margin-left:1em\" type=\"radio\" name=\"locale\" value=\"ru\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In Russian</span>\r\n </div>\r\n <textarea data-drafts-id=\"CommentReplyFrame\" class=\"wysiwyg\" name=\"editContent\" rows=\"20\" style=\"width:99%;\"></textarea>\r\n <div class=\"error error__content\"></div>\r\n <div style=\"text-align:center;\">\r\n <input type=\"button\" name=\"preview\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Preview\"/>\r\n <input type=\"button\" name=\"save\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Save\"/>\r\n </div>\r\n</div>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n\r\nvar firstPreview10585 = true;\r\nvar lastPreviewContent10585 = '';\r\n\r\nif (!window.moveCommentRevision) {\r\n moveCommentRevision = function(e, dir) {\r\n var p = e.parent();\r\n var revisionCount = parseInt(p.attr(\"revisionCount\"));\r\n var revision = parseInt(p.attr(\"revision\"));\r\n var next = revision + dir;\r\n var commentId = p.attr(\"commentId\");\r\n if (next >= 1 && next <= revisionCount) {\r\n $.post(\r\n \"/data/comment-data\",\r\n {action: \"revision\", commentId: commentId, revision: next},\r\n function(json) {\r\n if (json.success == \"true\") {\r\n var parentDiv = e;\r\n\r\n while (parentDiv !== null && (parentDiv[0].nodeName.toLowerCase() !== \"td\" || !parentDiv.hasClass(\"right\"))) {\r\n parentDiv = parentDiv.parent();\r\n }\r\n\r\n if (parentDiv === null) {\r\n return;\r\n }\r\n\r\n parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\").html(json.content);\r\n Codeforces.setupSpoilers(parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\"));\r\n p.attr(\"revision\", next);\r\n p.find(\"span.revision\").text(next);\r\n if (next == 1) {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"visible\");\r\n }\r\n if (next == revisionCount) {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"visible\");\r\n }\r\n\r\n window.updateTypography();\r\n MathJax.Hub.Typeset();\r\n } else {\r\n alert(e.error);\r\n }\r\n },\r\n \"json\"\r\n );\r\n }\r\n };\r\n}\r\n\r\n$(\"div[commentableId=10585] a.leftRevision\").click(function () {\r\n window.moveCommentRevision($(this), -1);\r\n return false;\r\n});\r\n\r\n$(\"div[commentableId=10585] a.rightRevision\").click(function () {\r\n window.moveCommentRevision($(this), +1);\r\n return false;\r\n});\r\n\r\n\r\n\r\n });\n </script>\n\r\n\r\n <script src=\"//codeforces.org/s/81027/js/swfobject-2.2.min.js\" type=\"text/javascript\"></script>\n <script src=\"//codeforces.org/s/81027/js/ftaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n if (window.evercookie) {\n var ec = new evercookie({\n history: false,\n silverlight: false,\n baseurl: '',\n asseturi: '/assets',\n phpuri: '/2fdcd78',\n pngPath: '/eps',\n etagPath: '/ees',\n cachePath: '/ecs'\n });\n\n var randomNumber = function () {\n return Math.random().toString(36).substr(2);\n };\n\n var randomToken = function () {\n return (randomNumber() + randomNumber()).substring(0, 18);\n };\n\n window._ftaa = \"\";\n\n ec.get(\"70a7c28f3de\", function (value) {\n window._ftaa = value;\n if (!window._ftaa) {\n window._ftaa = randomToken();\n ec.set(\"70a7c28f3de\", window._ftaa);\n }\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n } else {\n window._ftaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\n <script src=\"//codeforces.org/s/81027/js/bfaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n var fpCallback = function() {\n Fingerprint2.get({}, function(components) {\n window._bfaa = Fingerprint2.x64hash128(components.map(function (pair) { return pair.value }).join(), 31);\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n };\n if (typeof Fingerprint2 !== 'undefined') {\n if (window.requestIdleCallback) {\n requestIdleCallback(fpCallback)\n } else {\n setTimeout(fpCallback, 500)\n }\n } else {\n window._bfaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"a.new-root-comment\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n\r\n $(\".comment-table .reply a\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".vote-for-comment\").mouseover(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").mouseout(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").click(function () {\r\n var vote = $(this);\r\n var commentId = $(this).parent().attr(\"commentid\");\r\n var commentRating = $(this).parent().attr(\"data-commentRating\");\r\n var direction = $(this).attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n $.post(\"/data/comment/vote\", {commentId: commentId, _tta: Codeforces.tta(), vote: direction, commentRating: commentRating}, function(data) {\r\n if (direction != 0 && !ownComment && data[\"success\"] == \"true\") {\r\n vote.parent().find(\".vote-for-comment\").attr(\"voteDirection\", 0);\r\n if (direction == 1)\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n else {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.closest(\".CommentVoteFrame\").find(\".ComplaintFrame\").css(\"display\", \"inline-block\");\r\n }\r\n vote.find(\"img\").attr(\"popacity\", \"1.0\");\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n vote.parent().find(\".commentRating\").html(data[\"commentRating\"]);\r\n }\r\n Codeforces.showMessage(data[\"message\"]);\r\n }, \"json\");\r\n return false;\r\n });\r\n\r\n $(\".negative-comment-vote\").closest(\".comment-table\").addClass(\"comment-bad\");\r\n\r\n $(\".troll-comment-vote\").closest(\".comment\").css(\"display\", \"none\");\r\n\r\n $(\".too-negative-comment-vote\").closest(\".comment-table\").each(function () {\r\n var e = $(this);\r\n e.addClass(\"comment-too-bad\");\r\n var commentId = e.attr(\"commentId\");\r\n $(\"<div class='bad-comment-replacement ttypography'>The comment is hidden because of too negative feedback, click <a href=# class=show-bad-comment-link>here</a> to view it</div>\").appendTo(\r\n e.find(\".right\")\r\n );\r\n e.find(\".comment-content\").hide();\r\n e.find(\".show-bad-comment-link\").click(function () {\r\n e.find(\".comment-content\").show();\r\n e.find(\".bad-comment-replacement\").hide();\r\n return false;\r\n });\r\n });\r\n });\n </script>\n </div>\r\n\r\n <style type=\"text/css\">\r\n .new-comments-box {\r\n padding: 0.5em;\r\n width: 22px;\r\n font-size: 1.3rem;\r\n font-weight: bold !important;\r\n\r\n position: fixed;\r\n top: 40%;\r\n right: 0;\r\n opacity: 0.2;\r\n color: white;\r\n text-align: center;\r\n\r\n border: 1px solid #222;\r\n background-color: #888 !important;\r\n border-radius: 3px;\r\n -moz-border-radius: 3px;\r\n -webkit-border-radius: 3px;\r\n }\r\n\r\n .new-comments-box:hover {\r\n opacity: 1;\r\n }\r\n\r\n .new-comments-box .dir:hover {\r\n background: #3B5998 !important;\r\n cursor: pointer;\r\n }\r\n </style>\r\n\r\n <div class=\"new-comments-box\" data-position=\"outside\" data-index=\"-1\" style=\"display: none;\">\r\n <div class=\"up dir\" title=\"Ctrl+Up\">↑<hr/>\r\n </div>\r\n <div class=\"info\" title=\"New comments\"></div>\r\n <div class=\"down dir\" title=\"Ctrl+Down\">\r\n <hr/>↓\r\n </div>\r\n </div>\r\n\r\n <script>\r\n $(\".show-archived-checkbox\").change(function () {\r\n const checked = $(this).is(\":checked\");\r\n $.post(\"/data/comment-data\", {action: \"setShowArchived\", checked}, function (json) {\r\n if (json[\"success\"] !== \"true\") {\r\n alert(json[\"error\"]);\r\n } else {\r\n if (checked) {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are now displayed\")\r\n } else {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are no longer displayed\")\r\n }\r\n }\r\n });\r\n return false;\r\n });\r\n\r\n function gotoComment(direction) {\r\n var box = $(\".new-comments-box\");\r\n var index = parseInt(box.attr(\"data-index\"));\r\n if (index == -1)\r\n index = 0;\r\n else\r\n index = Math.max(0, Math.min(parseInt(box.find(\".info\").text()) - 1, index + direction));\r\n box.attr(\"data-index\", index);\r\n var comment = $($(\".comment .highlight-blue[commentId]\").get(index));\r\n $('html, body').animate({\r\n 'scrollTop': Math.max(0, comment.offset().top - ($(window).height() - comment.height()) / 2)\r\n });\r\n return false;\r\n }\r\n\r\n $(\".new-comments-box .down\").click(function () {\r\n return gotoComment(1);\r\n });\r\n\r\n $(\".new-comments-box .up\").click(function () {\r\n return gotoComment(-1);\r\n });\r\n\r\n $(document).keydown(function (e) {\r\n var code = (e.keyCode ? e.keyCode : e.which);\r\n if (e.ctrlKey) {\r\n if (code == 38 || code == 40) {\r\n gotoComment(code - 39);\r\n }\r\n }\r\n });\r\n\r\n var newCommentCount = $(\".comment .highlight-blue[commentId]\").length;\r\n if (newCommentCount > 0) {\r\n $(\".new-comments-box .info\").text(newCommentCount);\r\n $(\".new-comments-box\").show();\r\n }\r\n\r\n $('table.comment-table').mouseenter(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").addClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n\r\n $('table.comment-table').mouseleave(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").removeClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n </script>\r\n\r\n\r\n\r\n <script>\r\n function adjustTopicComplainFrames() {\r\n let topicIds = [];\r\n\r\n $(\".has-topic-id\").each(function () {\r\n const $this = $(this);\r\n const topicId = $this.attr(\"topicId\");\r\n if (topicId) {\r\n topicIds.push(topicId);\r\n }\r\n });\r\n\r\n $.post(\"/data/topics\", {\r\n action: \"findComplainableTopicIds\",\r\n topicIds: topicIds.join(\",\")\r\n }, function (json) {\r\n if (json[\"success\"] === \"true\") {\r\n for (const topicId of json[\"complainableTopicIds\"].split(\",\")) {\r\n $(\".has-topic-id[topicId=\" + topicId + \"]\").each(function () {\r\n $(this).find(\".meta .ComplaintFrame\").css(\"display\", \"inline-block\");\r\n });\r\n }\r\n }\r\n }, \"json\");\r\n }\r\n\r\n $(function () {\r\n adjustTopicComplainFrames();\r\n })\r\n </script>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-10569\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 10569, _tta: Codeforces.tta(), topicRevisionId: 36378, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-10569\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 10569, _tta: Codeforces.tta(), topicRevisionId: 36378, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n </div>\r\n </div>\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 22:13:04</span> (h1).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/81027/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/81027/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/81027/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/81027/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-81027.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'8128758f5b7075a7',t:'MTY5NjcwNTk4NC4yOTcwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"}}},{"rowIdx":1945,"cells":{"problem_id":{"kind":"string","value":"385B"},"contest":{"kind":"string","value":"385"},"problem":{"kind":"string","value":"B"},"lang":{"kind":"string","value":"en"},"problem_title":{"kind":"string","value":"B. Bear and Strings"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">B. Bear and Strings</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>The bear has a string <span class=\"tex-span\"><i>s</i> = <i>s</i><sub class=\"lower-index\">1</sub><i>s</i><sub class=\"lower-index\">2</sub>... <i>s</i><sub class=\"lower-index\">|<i>s</i>|</sub></span> (record <span class=\"tex-span\">|<i>s</i>|</span> is the string's length), consisting of lowercase English letters. The bear wants to count the number of such pairs of indices <span class=\"tex-span\"><i>i</i>, <i>j</i></span> <span class=\"tex-span\">(1 ≤ <i>i</i> ≤ <i>j</i> ≤ |<i>s</i>|)</span>, that string <span class=\"tex-span\"><i>x</i>(<i>i</i>, <i>j</i>) = <i>s</i><sub class=\"lower-index\"><i>i</i></sub><i>s</i><sub class=\"lower-index\"><i>i</i> + 1</sub>... <i>s</i><sub class=\"lower-index\"><i>j</i></sub></span> contains at least one string \"<span class=\"tex-font-style-tt\">bear</span>\" as a substring.</p><p>String <span class=\"tex-span\"><i>x</i>(<i>i</i>, <i>j</i>)</span> contains string \"<span class=\"tex-font-style-tt\">bear</span>\", if there is such index <span class=\"tex-span\"><i>k</i></span> <span class=\"tex-span\">(<i>i</i> ≤ <i>k</i> ≤ <i>j</i> - 3)</span>, that <span class=\"tex-span\"><i>s</i><sub class=\"lower-index\"><i>k</i></sub> = <i>b</i></span>, <span class=\"tex-span\"><i>s</i><sub class=\"lower-index\"><i>k</i> + 1</sub> = <i>e</i></span>, <span class=\"tex-span\"><i>s</i><sub class=\"lower-index\"><i>k</i> + 2</sub> = <i>a</i></span>, <span class=\"tex-span\"><i>s</i><sub class=\"lower-index\"><i>k</i> + 3</sub> = <i>r</i></span>.</p><p>Help the bear cope with the given problem.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains a non-empty string <span class=\"tex-span\"><i>s</i></span> <span class=\"tex-span\">(1 ≤ |<i>s</i>| ≤ 5000)</span>. It is guaranteed that the string only consists of lowercase English letters.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print a single number — the answer to the problem.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>bearbtear<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>6<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>bearaabearc<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>20<br/></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>In the first sample, the following pairs <span class=\"tex-span\">(<i>i</i>, <i>j</i>)</span> match: <span class=\"tex-span\">(1, 4), (1, 5), (1, 6), (1, 7), (1, 8), (1, 9)</span>.</p><p>In the second sample, the following pairs <span class=\"tex-span\">(<i>i</i>, <i>j</i>)</span> match: <span class=\"tex-span\">(1, 4), (1, 5), (1, 6), (1, 7), (1, 8), (1, 9), (1, 10), (1, 11), (2, 10), (2, 11), (3, 10), (3, 11), (4, 10), (4, 11), (5, 10), (5, 11), (6, 10), (6, 11), (7, 10), (7, 11)</span>.</p></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"383f86638d999508540ae0591d51e0b0\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - B - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"3200a641fa0ca6f78af7a41b57e5016ab7be9096\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - B - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/73366/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/73366/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/73366/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/73366/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/73366/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/73366/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/73366/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/73366/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/73366/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/73366/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/73366/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/73366/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/73366/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/73366/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/sidebar-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/a037fe51637846d9c7c725713cd840ea/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='383f86638d999508540ae0591d51e0b0'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/73366/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/73366/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fcontest%2F385%2Fproblem%2FB%3Flocale%3Den\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"current\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='383f86638d999508540ae0591d51e0b0'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:100%;\"><a style=\"color: black\" href=\"/contest/385\">Codeforces Round 226 (Div. 2)</a></th>\n </tr>\n <tr>\n <td class=\"left bottom\" colspan=\"1\"><span class=\"contest-state-phase\">Finished</span></td>\n </tr>\n </tbody>\n </table>\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Practice?\n <div class=\"top-links\">\n </div>\n </div>\n<div>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Want to solve the contest problems after the official contest ends? Just register for practice and you will be able to submit solutions.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"\" method=\"post\"><input type='hidden' name='csrf_token' value='383f86638d999508540ae0591d51e0b0'/>\r\n <input type=\"hidden\" name=\"action\" value=\"registerForPractice\"/>\r\n <input type=\"submit\" name=\"submit\" value=\"Register for practice\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div> \r\n</div>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox ContestVirtualFrame borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Virtual participation <i class=\"sidebar-caption-icon las la-angle-down\"></i>\r\n\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\" \"\r\n\r\n data-page-url=\"/data/sidebarFrames\"\r\n\r\n>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests.\n\nIf you've seen these problems, a virtual contest is not for you - solve these problems in the archive.\n\nIf you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.\n\nNever use someone else's code, read the tutorials or communicate with other person during a virtual contest.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"/contest/385/virtual\" method=\"get\">\r\n <input type=\"submit\" name=\"submit\" value=\"Start virtual contest\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div>\r\n</div>\r\n <script>\r\n $(function () {\r\n $(\".ContestVirtualFrame .sidebar-caption-icon\").click(function() {\r\n $(this).toggleClass(\"la-angle-down la-angle-right\");\r\n const $target = $(this).parent().next();\r\n $target.toggle();\r\n const dataPageUrl = $target.attr(\"data-page-url\");\r\n const collapsed = $(this).hasClass(\"la-angle-right\");\r\n const params = {\r\n action: \"setCollapsed\",\r\n sidebarFrameSimpleClassName: \"ContestVirtualFrame\",\r\n collapsed\r\n };\r\n $.each($target[0].attributes, function(i, a) {\r\n const name = a.name;\r\n if (name.startsWith(\"data-extra-key-\")) {\r\n const key = a.value;\r\n const keyIndex = parseInt(name.substring(\"data-extra-key-\".length));\r\n const value = $target.attr(\"data-extra-value-\" + keyIndex);\r\n params[key] = value;\r\n }\r\n });\r\n $.post(dataPageUrl, params, function (result) {\r\n if (result[\"success\"] !== \"true\") {\r\n Codeforces.showMessage(\"Failed to save collapsed state.\");\r\n }\r\n }, \"json\");\r\n return false;\r\n });\r\n })\r\n </script>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Problem tags\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Brute force\">\r\n brute force\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Greedy algorithms\">\r\n greedy\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Implementation problems, programming technics, simulation\">\r\n implementation\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Mathematics including integration, differential equations, etc\">\r\n math\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Prefix- and Z-functions, suffix structures, Knuth–Morris–Pratt algorithm, etc\">\r\n strings\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Difficulty\">\r\n *1200\r\n</span>\r\n </div>\n <div style=\"clear:both;text-align:right;font-size:1.1rem;\">\r\n <span title=\"Please login into the Codeforces\" class=\"notice\">No tag edit access</span>\r\n </div>\r\n</div>\r\n </div>\n\r\n<form id=\"addTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='383f86638d999508540ae0591d51e0b0'/>\r\n <input name=\"action\" type=\"hidden\" value=\"addTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"5932\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<form id=\"removeTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='383f86638d999508540ae0591d51e0b0'/>\r\n <input name=\"action\" type=\"hidden\" value=\"removeTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"5932\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<script type=\"text/javascript\">\r\n $(\".tag-box img\").click(function () {\r\n var tagName = $(this).attr(\"value\");\r\n Codeforces.confirm(\"Are you sure you want to remove this tag?\", function () {\r\n $(\"#removeTagForm input[name=tagName]\").val(tagName);\r\n $(\"#removeTagForm\").submit();\r\n }, function () {\r\n }, \"Yes\", \"No\");\r\n });\r\n\r\n $(\"#addTagLink\").click(function () {\r\n $(this).hide();\r\n $(\"#addTagLabel\").show();\r\n return false;\r\n });\r\n\r\n $(\"#addTagSelect\").change(function () {\r\n var tagName = $(this).val();\r\n if (tagName === \"\") {\r\n $(\"#addTagLabel\").hide();\r\n $(\"#addTagLink\").show();\r\n } else {\r\n $(\"#addTagForm input[name=tagName]\").val(tagName);\r\n $(\"#addTagForm\").submit();\r\n }\r\n });\r\n</script>\r\n\r\n<style type=\"text/css\">\r\n#new-resource-form tr td {\r\npadding-top: 0.5em;\r\n}\r\n#new-resource-form input:not([type=\"submit\"]) {\r\nfont-size: 0.8em;\r\n}\r\n#new-resource-form select {\r\nfont-size: 0.8em;\r\n}\r\n.new-resource-error {\r\nfont-size: 0.8em;\r\n}\r\n.resource-locale {\r\ncolor: #666;\r\nfont-family: Consolas, \"Andale Mono WT\", \"Andale Mono\", \"Lucida Console\", \"Lucida Sans Typewriter\", \"DejaVu Sans Mono\", \"Bitstream Vera Sans Mono\", \"Liberation Mono\", \"Nimbus Mono L\", Monaco, \"Courier New\", Courier, monospace;\r\n}\r\n</style>\r\n<div class=\"roundbox sidebox sidebar-menu borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Contest materials\n<div class=\"top-links\">\n</div>\n</div>\n<ul>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/10512\" title=\"Codeforces Round #226 (Div. 2)\" target=\"_blank\">Announcement</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"2193:2194\" resourceName=\"Announcement\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/10514\" title=\"Codeforces Round #226 (Div. 2) — Editorial\" target=\"_blank\">Tutorial</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"2197:2198\" resourceName=\"Tutorial\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n</ul>\r\n</div></div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li class=\"current selectedLava\"><a\r\n href=\"/contest/385\">Problems</a></li>\r\n <li><a\r\n href=\"/contest/385/submit\">Submit Code</a></li>\r\n <li><a\r\n href=\"/contest/385/my\">My Submissions</a></li>\r\n <li><a\r\n href=\"/contest/385/status\">Status</a></li>\r\n <li><a\r\n href=\"/contest/385/hacks\">Hacks</a></li>\r\n <li><a\r\n href=\"/contest/385/room/1\">Room</a></li>\r\n <li><a\r\n href=\"/contest/385/standings\">Standings</a></li>\r\n <li><a\r\n href=\"/contest/385/customtest\">Custom Invocation</a></li>\r\n</ul>\r\n</div>\n\r\n <style>\r\n #facebox .content:has(.diff-popup) {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n }\r\n\r\n .testCaseMarker {\r\n position: absolute;\r\n font-weight: bold;\r\n font-size: 1rem;\r\n }\r\n\r\n .diff-popup {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n display: none;\r\n overflow: auto;\r\n }\r\n\r\n .input-output-copier {\r\n font-size: 1.2rem;\r\n float: right;\r\n color: #888 !important;\r\n cursor: pointer;\r\n border: 1px solid rgb(185, 185, 185);\r\n padding: 3px;\r\n margin: 1px;\r\n line-height: 1.1rem;\r\n text-transform: none;\r\n }\r\n\r\n .input-output-copier:hover {\r\n background-color: #def;\r\n }\r\n\r\n .test-explanation textarea {\r\n width: 100%;\r\n height: 1.5em;\r\n }\r\n\r\n .pending-submission-message {\r\n color: darkorange !important;\r\n }\r\n </style>\r\n <script>\r\n const OPENING_SPACE = String.fromCharCode(1001);\r\n const CLOSING_SPACE = String.fromCharCode(1002);\r\n\r\n const nodeToText = function (node, pre) {\r\n let result = [];\r\n\r\n if (node.tagName === \"SCRIPT\" || node.tagName === \"math\"\r\n || (node.classList && node.classList.contains(\"input-output-copier\")))\r\n return [];\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(OPENING_SPACE);\r\n }\r\n\r\n if (node.nodeType === Node.TEXT_NODE) {\r\n let s = node.textContent;\r\n if (!pre) {\r\n s = s.replace(/\\s+/g, \" \");\r\n }\r\n if (s.length > 0) {\r\n result.push(s);\r\n }\r\n }\r\n\r\n if (pre && node.tagName === \"BR\") {\r\n result.push(\"\\n\");\r\n }\r\n\r\n node.childNodes.forEach(function (child) {\r\n result.push(nodeToText(child, node.tagName === \"PRE\").join(\"\"));\r\n });\r\n\r\n if (node.tagName === \"DIV\"\r\n || node.tagName === \"P\"\r\n || node.tagName === \"PRE\"\r\n || node.tagName === \"UL\"\r\n || node.tagName === \"LI\"\r\n ) {\r\n result.push(\"\\n\");\r\n }\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(CLOSING_SPACE);\r\n }\r\n\r\n return result;\r\n }\r\n\r\n const isSpecial = function (c) {\r\n return c === ',' || c === '.' || c === ';' || c === ')' || c === ' ';\r\n }\r\n\r\n const convertStatementToText = function(statmentNode) {\r\n const text = nodeToText(statmentNode, false).join(\"\").replace(/ +/g, \" \").replace(/\\n\\n+/g, \"\\n\\n\");\r\n let result = [];\r\n for (let i = 0; i < text.length; i++) {\r\n const c = text.charAt(i);\r\n if (c === OPENING_SPACE) {\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"B\" data-uuid=\"ps_bc9341a75e2073a4b18bae0419f7be32fe5e55b1\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">B. Bear and Strings</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>The bear has a string <span class=\"tex-span\"><i>s</i> = <i>s</i><sub class=\"lower-index\">1</sub><i>s</i><sub class=\"lower-index\">2</sub>... <i>s</i><sub class=\"lower-index\">|<i>s</i>|</sub></span> (record <span class=\"tex-span\">|<i>s</i>|</span> is the string's length), consisting of lowercase English letters. The bear wants to count the number of such pairs of indices <span class=\"tex-span\"><i>i</i>, <i>j</i></span> <span class=\"tex-span\">(1 ≤ <i>i</i> ≤ <i>j</i> ≤ |<i>s</i>|)</span>, that string <span class=\"tex-span\"><i>x</i>(<i>i</i>, <i>j</i>) = <i>s</i><sub class=\"lower-index\"><i>i</i></sub><i>s</i><sub class=\"lower-index\"><i>i</i> + 1</sub>... <i>s</i><sub class=\"lower-index\"><i>j</i></sub></span> contains at least one string "<span class=\"tex-font-style-tt\">bear</span>" as a substring.</p><p>String <span class=\"tex-span\"><i>x</i>(<i>i</i>, <i>j</i>)</span> contains string "<span class=\"tex-font-style-tt\">bear</span>", if there is such index <span class=\"tex-span\"><i>k</i></span> <span class=\"tex-span\">(<i>i</i> ≤ <i>k</i> ≤ <i>j</i> - 3)</span>, that <span class=\"tex-span\"><i>s</i><sub class=\"lower-index\"><i>k</i></sub> = <i>b</i></span>, <span class=\"tex-span\"><i>s</i><sub class=\"lower-index\"><i>k</i> + 1</sub> = <i>e</i></span>, <span class=\"tex-span\"><i>s</i><sub class=\"lower-index\"><i>k</i> + 2</sub> = <i>a</i></span>, <span class=\"tex-span\"><i>s</i><sub class=\"lower-index\"><i>k</i> + 3</sub> = <i>r</i></span>.</p><p>Help the bear cope with the given problem.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains a non-empty string <span class=\"tex-span\"><i>s</i></span> <span class=\"tex-span\">(1 ≤ |<i>s</i>| ≤ 5000)</span>. It is guaranteed that the string only consists of lowercase English letters.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print a single number — the answer to the problem.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>bearbtear<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>6<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>bearaabearc<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>20<br /></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>In the first sample, the following pairs <span class=\"tex-span\">(<i>i</i>, <i>j</i>)</span> match: <span class=\"tex-span\">(1, 4), (1, 5), (1, 6), (1, 7), (1, 8), (1, 9)</span>.</p><p>In the second sample, the following pairs <span class=\"tex-span\">(<i>i</i>, <i>j</i>)</span> match: <span class=\"tex-span\">(1, 4), (1, 5), (1, 6), (1, 7), (1, 8), (1, 9), (1, 10), (1, 11), (2, 10), (2, 11), (3, 10), (3, 11), (4, 10), (4, 11), (5, 10), (5, 11), (6, 10), (6, 11), (7, 10), (7, 11)</span>.</p></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=B]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== statementText) {\r\n $problem.find(\".diff-notifier\").show();\r\n\r\n $problem.find(\".diff-notifier-close\").click(function() {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n $problem.find(\".diff-notifier\").hide();\r\n });\r\n\r\n $problem.find(\"a.view-changes\").click(function() {\r\n $.post(\"/data/diff\", {action: \"getDiff\", a: previousStatementText, b: statementText}, function (result) {\r\n if (result[\"success\"] === \"true\") {\r\n Codeforces.facebox(\".diff-popup\", \"//codeforces.org/s/73366\");\r\n $(\"#facebox .diff-popup\").html(result[\"diff\"]);\r\n }\r\n }, \"json\");\r\n });\r\n }\r\n } else {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n }\r\n });\r\n });\r\n </script>\r\n\r\n\r\n<script type=\"text/javascript\">\r\n $(document).ready(function () {\r\n window.changedTests = new Set();\r\n\r\n function endsWith(string, suffix) {\r\n return string.indexOf(suffix, string.length - suffix.length) !== -1;\r\n }\r\n\r\n const inputFileDiv = $(\"div.input-file\");\r\n const inputFile = inputFileDiv.text();\r\n const outputFileDiv = $(\"div.output-file\");\r\n const outputFile = outputFileDiv.text();\r\n\r\n\r\n if (!endsWith(inputFile, \"standard input\")\r\n && !endsWith(inputFile, \"standard input\")) {\r\n inputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n if (!endsWith(outputFile, \"standard output\")\r\n && !endsWith(outputFile, \"standard output\")) {\r\n outputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n const titleDiv = $(\"div.header div.title\");\r\n\r\n\r\n\r\n String.prototype.replaceAll = function (search, replace) {\r\n return this.split(search).join(replace);\r\n };\r\n\r\n $(\".sample-test .title\").each(function () {\r\n const preId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n const cpyId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n\r\n $(this).parent().find(\"pre\").attr(\"id\", preId);\r\n const $copy = $(\"<div title='Copy' data-clipboard-target='#\" + preId + \"' id='\" + cpyId + \"' class='input-output-copier'>Copy</div>\");\r\n $(this).append($copy);\r\n\r\n const clipboard = new Clipboard('#' + cpyId, {\r\n text: function (trigger) {\r\n const pre = document.querySelector('#' + preId);\r\n const lines = pre.querySelectorAll(\".test-example-line\");\r\n return Codeforces.filterClipboardText(pre.innerText, lines.length);\r\n }\r\n });\r\n\r\n const isInput = $(this).parent().hasClass(\"input\");\r\n\r\n clipboard.on('success', function (e) {\r\n if (isInput) {\r\n Codeforces.showMessage(\"The example input has been copied into the clipboard\");\r\n } else {\r\n Codeforces.showMessage(\"The example output has been copied into the clipboard\");\r\n }\r\n e.clearSelection();\r\n });\r\n });\r\n\r\n $(\".test-form-item input\").change(function () {\r\n addPendingSubmissionMessage($($(this).closest(\"form\")), \"You changed the answer, do not forget to submit it if you want to save the changes\");\r\n const index = $(this).closest(\".problemindexholder\").attr(\"problemindex\");\r\n let test = \"\";\r\n $(this).closest(\"form input\").each(function () {\r\n const test_ = $(this).attr(\"name\");\r\n if (test_ && test_.substring(0, 4) === \"test\") {\r\n test = test_;\r\n }\r\n });\r\n if (index.length > 0 && test.length > 0) {\r\n const indexTest = index + \"::\" + test;\r\n window.changedTests.add(indexTest);\r\n }\r\n });\r\n\r\n $(window).on('beforeunload', function () {\r\n if (window.changedTests.size > 0) {\r\n return 'Dialog text here';\r\n }\r\n });\r\n\r\n autosize($('.test-explanation textarea'));\r\n\r\n $(\".test-example-line\").hover(function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n let top = 1E20;\r\n let left = 1E20;\r\n let problem = $(this).closest(\".problemindexholder\");\r\n $(this).closest(\".input\").find(\".\" + clazz).css(\"background-color\", \"#FFFDE7\").each(function() {\r\n top = Math.min(top, $(this).offset().top);\r\n left = Math.min(left, $(this).offset().left);\r\n });\r\n let testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n if (testCaseMarker.length === 0) {\r\n const html = \"<div class=\\\"testCaseMarker testCaseMarker_\" + end + \" notice\\\"></div>\";\r\n problem.append($(html));\r\n testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n }\r\n if (testCaseMarker) {\r\n testCaseMarker.show()\r\n .offset({top, left: left - 20})\r\n .text(end);\r\n }\r\n }\r\n }\r\n });\r\n }, function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n $(\".\" + clazz).css(\"background-color\", \"\");\r\n $(this).closest(\".problemindexholder\").find(\".testCaseMarker_\" + end).hide();\r\n }\r\n }\r\n });\r\n });\r\n\r\n });\r\n</script>\r\n\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 05:38:12</span> (j3).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/73366/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/73366/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/73366/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/73366/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-73366.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'8122c43cb9e99d3f',t:'MTY5NjY0NjI5Mi4wMjkwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"},"long_tags":{"kind":"string","value":"[\"Brute force\", \"Greedy algorithms\", \"Implementation problems, programming technics, simulation\", \"Mathematics including integration, differential equations, etc\", \"Prefix- and Z-functions, suffix structures, Knuth\\u2013Morris\\u2013Pratt algorithm, etc\"]"},"short_tags":{"kind":"string","value":"[\"brute force\", \"greedy\", \"implementation\", \"math\", \"strings\", \"*1200\"]"},"tutorial_link":{"kind":"string","value":"https://codeforces.com/blog/entry/10514"},"tutorial_page":{"kind":"string","value":"\r\n\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"b0edd04b6e615eea61c4a67daabca579\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"h1\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Codeforces Round #226 (Div. 2) — Editorial - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n \n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Codeforces Round #226 (Div. 2) — Editorial - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/81027/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/81027/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/81027/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/81027/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/81027/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/81027/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/81027/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/81027/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/81027/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/81027/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/81027/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/81027/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/81027/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/81027/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/573cedc6b04c15481941f418269f4057/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='b0edd04b6e615eea61c4a67daabca579'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/81027/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fblog%2Fentry%2F10514\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='b0edd04b6e615eea61c4a67daabca579'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Pay attention\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n <div style=\"text-align:center;border-bottom: 1px solid rgb(185, 185, 185);margin:0 -0.5em 0.5em -0.5em;padding: 0 1em 0.5em 1em;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 1, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:51:56</span><br/><a href=\"/contestRegistration/1876\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n <div style=\"text-align:center;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 2, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:51:56</span><br/><a href=\"/contestRegistration/1877\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='b0edd04b6e615eea61c4a67daabca579'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n </label>\r\n </div>\r\n <div style=\"padding: 0 1em 1em 1em;text-align:right;\">\r\n <input style=\"height:1.65em;padding:0 0.75em;\" type=\"submit\" value=\"Find\"/>\r\n </div>\r\n </form>\r\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".handleBox\").autocomplete(\"/data/handles\", {\r\n delay: 200,\r\n width: 200,\r\n selectFirst: false,\r\n matchContains: true,\r\n minChars: 3\r\n });\r\n $(\".handleForm\").attr(\"autocomplete\", \"off\").submit(function () {\r\n var link = \"/profile/userHandle\".replace(\r\n \"userHandle\", $(this).find(\".handleBox\").val()\r\n );\r\n window.location = link;\r\n return false;\r\n });\r\n });\n </script>\n\r\n\r\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Recent actions\n <div class=\"top-links\">\n </div>\n </div>\n <div class=\"recent-actions\">\r\n <ul>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/121073\">Meta Hacker Cup 2023 Round 1</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/.Danet\" title=\"Expert .Danet\" class=\"rated-user user-blue\">.Danet</a> →\r\n <a href=\"/blog/entry/121172\">[TLE on pretest1]</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\" class=\"rated-user user-red\">Pyqe</a> →\r\n <a href=\"/blog/entry/121025\">Codeforces Round #902 (Div. 1, Div. 2, based on COMPFEST 15 — Final Round)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pranshu_Pandya\" title=\"Specialist Pranshu_Pandya\" class=\"rated-user user-cyan\">Pranshu_Pandya</a> →\r\n <a href=\"/blog/entry/121171\">An Interesting Tree Problem</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/sszcdjr\" title=\"Master sszcdjr\" class=\"rated-user user-orange\">sszcdjr</a> →\r\n <a href=\"/blog/entry/119859\">Codeforces Round 896 (Div. 1, Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/119880\">It's Happening! Meta Hacker Cup 2023 Schedule</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/DaviddeGea1\" title=\"Expert DaviddeGea1\" class=\"rated-user user-blue\">DaviddeGea1</a> →\r\n <a href=\"/blog/entry/70917\">Number of ways of dividing an array into 2 parts such that sum of each part is > k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bekh\" title=\"Master Bekh\" class=\"rated-user user-orange\">Bekh</a> →\r\n <a href=\"/blog/entry/74245\">Questions and doubts regarding Aliens DP trick</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a> →\r\n <a href=\"/blog/entry/8192\">Codeforces Round #190 — Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/hocky\" title=\"Candidate Master hocky\" class=\"rated-user user-violet\">hocky</a> →\r\n <a href=\"/blog/entry/95323\">FBHC wuining uw Day? Incwease uw stacc size! (ㅅ´ ˘ `)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/liouzhou_101\" title=\"International Master liouzhou_101\" class=\"rated-user user-orange\">liouzhou_101</a> →\r\n <a href=\"/blog/entry/87598\">Editorial of Codeforces Round #700</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/yeon_gist\" title=\"Newbie yeon_gist\" class=\"rated-user user-gray\">yeon_gist</a> →\r\n <a href=\"/blog/entry/121170\">plusMinusPermutation computing error</a>\r\n <img alt=\"Text created or updated\" title=\"Text created or updated\" src=\"//codeforces.org/s/81027/images/icons/x-update-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/altforminuscontribution\" title=\"Newbie altforminuscontribution\" class=\"rated-user user-gray\">altforminuscontribution</a> →\r\n <a href=\"/blog/entry/121162\">My screen get unexpectedly big, what should I do</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/atcoder_official\" title=\"Unrated, atcoder_official\" class=\"rated-user user-black\">atcoder_official</a> →\r\n <a href=\"/blog/entry/121120\">We will hold UNIQUE VISION Programming Contest 2023 Autumn(AtCoder Beginner Contest 323)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/YouStill_DontKnowMeYet\" title=\"Candidate Master YouStill_DontKnowMeYet\" class=\"rated-user user-violet\">YouStill_DontKnowMeYet</a> →\r\n <a href=\"/blog/entry/117659\">[GYM] Al-Baath Collegiate Programming Contest 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/ankancool\" title=\"Expert ankancool\" class=\"rated-user user-blue\">ankancool</a> →\r\n <a href=\"/blog/entry/121136\">Invitation to AstroByte 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/GeZhiyuan\" title=\"Grandmaster GeZhiyuan\" class=\"rated-user user-red\">GeZhiyuan</a> →\r\n <a href=\"/blog/entry/120943\">Codeforces Round 901 (Div. 1, Div. 2) Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a> →\r\n <a href=\"/blog/entry/120772\">PSA: Increase your stack size before the Meta Hacker Cup, here's how</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/dino_merlin\" title=\"Expert dino_merlin\" class=\"rated-user user-blue\">dino_merlin</a> →\r\n <a href=\"/blog/entry/121145\">Intuitive approach for CEOI Kangaroo?</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/icecuber\" title=\"Grandmaster icecuber\" class=\"rated-user user-red\">icecuber</a> →\r\n <a href=\"/blog/entry/70018\">CSES DP section editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bn00b\" title=\"Newbie Bn00b\" class=\"rated-user user-gray\">Bn00b</a> →\r\n <a href=\"/blog/entry/98820\">[FEATURE REQUEST : ATCODER] TOPICS TAGS AND SORTING BY SOLVE COUNT</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a> →\r\n <a href=\"/blog/entry/121163\">AtCoder Regular Contest 166 Announcement</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/windva\" title=\"Grandmaster windva\" class=\"rated-user user-red\">windva</a> →\r\n <a href=\"/blog/entry/120644\">Codeforces Round 899 (Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Misa-Misa\" title=\"Expert Misa-Misa\" class=\"rated-user user-blue\">Misa-Misa</a> →\r\n <a href=\"/blog/entry/121157\">Someone please help me understand this.</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/shivam565\" title=\"Specialist shivam565\" class=\"rated-user user-cyan\">shivam565</a> →\r\n <a href=\"/blog/entry/108348\">Total number of subarrays with sum atmost k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n </ul>\r\n </div>\r\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/recent-actions\">Detailed →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n</div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li><a\r\n href=\"/profile/CleRIC\">CleRIC</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/CleRIC\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/CleRIC\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/CleRIC\">Submissions</a></li>\r\n <li><a\r\n href=\"/groups/with/CleRIC\">Groups</a></li>\r\n <li><a\r\n href=\"/contests/with/CleRIC\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/CleRIC\">Problemsetting</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/CleRIC\" style=\"text-decoration:none;color:black !important;\">CleRIC's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"10569\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/10514\"> <p>Codeforces Round #226 (Div. 2) — Editorial</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/CleRIC\" title=\"Candidate Master CleRIC\" class=\"rated-user user-violet\">CleRIC</a>,\r\n <span class=\"format-humantime\" title=\"Jan/23/2014 19:33\">10 years ago</span>,\r\n translation,\r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p><a href=\"/contest/385/problem/A\" title=\"Codeforces Round 226 (Div. 2)\">385A - Bear and Raspberry</a></p><p>In this task required to understand that the answer max(<span class=\"tex-span\"><i>a</i>[<i>i</i>] - <i>a</i>[<i>i</i> - 1] - <i>c</i></span>),<span class=\"tex-span\"><i>i</i></span> = <span class=\"tex-span\">2..<i>n</i></span> and don't forget that the answer not negative as Bear can not borrow in the debt barrel of honey.</p><p><a href=\"/contest/385/problem/B\" title=\"Codeforces Round 226 (Div. 2)\">385B - Bear and Strings</a></p><p>In this problem you could write a better solution than the naive. To do this, you can iterate through the first cycle of the left index <span class=\"tex-span\"><i>l</i></span> considered substring and the second cycle of the right index <span class=\"tex-span\"><i>r</i></span> considered substring <span class=\"tex-span\">(<i>l</i> ≤ <i>r</i>)</span>. If any position has been substring "bear", means all the strings <span class=\"tex-span\"><i>x</i>(<i>l</i>, <i>j</i>)</span> <span class=\"tex-span\">(<i>i</i> ≤ <i>j</i>)</span>, also contain "bear" as a substring. So we can add to the answer <span class=\"tex-span\">|<i>s</i>| - <i>j</i> + 1</span> and exit from the second cycle. Also needed to understand, that if the string <span class=\"tex-span\"><i>x</i>(<i>l</i>, <i>j</i>)</span> was not a substring "bear", then in row <span class=\"tex-span\"><i>x</i>(<i>l</i>, <i>j</i> + 1)</span> substring "bear" could appear only in the last four characters.</p><p><a href=\"/contest/385/problem/C\" title=\"Codeforces Round 226 (Div. 2)\">385C - Bear and Prime Numbers</a></p><p>In order to solve given problem, contestant should solve several subproblems :</p><p>1) First one is to compute amount of entries of each natural number between <span class=\"tex-span\">2</span> and <span class=\"tex-span\">10<sup class=\"upper-index\">7</sup></span> in given list. This subproblem can be solved by creating array <span class=\"tex-span\"><i>count</i></span> of <span class=\"tex-span\">10<sup class=\"upper-index\">7</sup></span> elements and increasing corresponding element when scanning input.</p><p>2) Second one is to compute <span class=\"tex-span\"><i>f</i>(<i>n</i>)</span>.</p><p>First of all, we need to find all primes less than <span class=\"tex-span\">10<sup class=\"upper-index\">7</sup></span> and then for each prime <span class=\"tex-span\"><i>n</i></span> compute <span class=\"tex-span\"><i>f</i>(<i>n</i>)</span>.</p><p>How to compute <span class=\"tex-span\"><i>f</i>(2)</span>? We should sum <span class=\"tex-span\"><i>count</i>[2]</span>,<span class=\"tex-span\"><i>count</i>[4]</span>,<span class=\"tex-span\"><i>count</i>[6]</span>,<span class=\"tex-span\"><i>count</i>[8]</span>,...</p><p>How to compute <span class=\"tex-span\"><i>f</i>(5)</span>? We should sum <span class=\"tex-span\"><i>count</i>[5]</span>,<span class=\"tex-span\"><i>count</i>[10]</span>,<span class=\"tex-span\"><i>count</i>[15]</span>,<span class=\"tex-span\"><i>count</i>[20]</span>,...</p><p>How to compute <span class=\"tex-span\"><i>f</i>(<i>n</i>)</span>? We should sum <span class=\"tex-span\"><i>count</i>[<i>n</i>]</span>,<span class=\"tex-span\"><i>count</i>[2·<i>n</i>]</span>,<span class=\"tex-span\"><i>count</i>[3·<i>n</i>]</span>,<span class=\"tex-span\"><i>count</i>[4·<i>n</i>]</span>,...</p><p>It can be seen that given algo is very similar to Sieve of Eratosthenes. (Info here <a href=\"http://e-maxx.ru/algo/eratosthenes_sieve\">http://e-maxx.ru/algo/eratosthenes_sieve</a>) So we can use this algo if we change it a little bit. Also, we will store results of calculation in array, e.g. <span class=\"tex-span\"><i>pre</i></span>. Namely, <span class=\"tex-span\"><i>pre</i>[<i>n</i>]</span> = <span class=\"tex-span\"><i>f</i>(<i>n</i>)</span>.</p><p>3) Now we can calculate partial sums of <span class=\"tex-span\"><i>pre</i></span> array. It can be made in a single pass just adding <span class=\"tex-span\"><i>pre</i>[<i>i</i> - 1]</span> to <span class=\"tex-span\"><i>pre</i>[<i>i</i>]</span>.</p><p>4) If we know partial sums of array then we can calculate sum of array elements between <span class=\"tex-span\"><i>l</i></span> and <span class=\"tex-span\"><i>r</i></span> in time proportional <span class=\"tex-span\"><i>O</i>(1)</span>, just calculate <span class=\"tex-span\"><i>pre</i>[<i>r</i>] - <i>pre</i>[<i>l</i> - 1]</span>.</p><p>5) Now we can read queries and immediately response to them. You shouldn't forget that right boundaries of intervals can be greater than <span class=\"tex-span\">10<sup class=\"upper-index\">7</sup></span>, so you can always decrease it to <span class=\"tex-span\">10<sup class=\"upper-index\">7</sup></span>, because all numbers in given list are less than <span class=\"tex-span\">10<sup class=\"upper-index\">7</sup></span>.</p><p><a href=\"/contest/385/problem/D\" title=\"Codeforces Round 226 (Div. 2)\">385D - Bear and Floodlight</a></p><p>In this task, it is crucial to understand that whether there is lighted part of road with length <span class=\"tex-span\"><i>dist</i></span> then next part should be lit in a such way that leftmost lighted point is touching with <span class=\"tex-span\"><i>dist</i></span>.</p><p>Let's suppose that road is lit from <span class=\"tex-span\"><i>l</i></span> to <span class=\"tex-span\"><i>d</i></span>. How we can find rightmost point on X axis that would be lit by next floodlight?</p><p>We can just use concepts of vector and rotation matrix.</p><p>Let's find vector <span class=\"tex-span\">(<i>dx</i>, <i>dy</i>)</span> from floodlight to point on X axis <span class=\"tex-span\">(<i>d</i>, 0)</span>. <span class=\"tex-span\">(<i>dx</i>, <i>dy</i>)</span> = <span class=\"tex-span\">(<i>d</i> - <i>x</i>, 0 - <i>y</i>)</span>.</p><p>Next point to rotate vector by <span class=\"tex-span\"><i>angle</i></span> degrees. We can use rotation matrix for this purpose.</p><p><span class=\"tex-span\">(<i>dx</i>, <i>dy</i>)</span> = <span class=\"tex-span\">(<i>dx</i>·<i>cos</i>(<i>angle</i>) - <i>dy</i>·<i>sin</i>(<i>angle</i>), <i>dx</i>·<i>sin</i>(<i>angle</i>) + <i>dy</i>·<i>cos</i>(<i>angle</i>))</span></p><p>Next, we should make second component <span class=\"tex-span\"><i>dy</i></span> of <span class=\"tex-span\">(<i>dx</i>, <i>dy</i>)</span> equal to <span class=\"tex-span\">1</span> by multiplying on coefficient <span class=\"tex-span\"><i>k</i></span>.</p><p>Now we can determine rightmost lighted point of X axis. It is <span class=\"tex-span\"><i>x</i> - <i>y</i>·<i>dx</i></span>.</p><p>You shouldn't forget that there is possibility for rightmost point to be infinitely far point.</p><p>From now on we can forget about geometry in this task.</p><p>Let's find fast way to determine optimal order of floodlights.</p><p>To achieve this goal, we can use dynamic programming approach. Namely, let's calculate answer for subsets of floodlights. Each subset would be represented as integer where <span class=\"tex-span\"><i>k</i></span> bit would be <span class=\"tex-span\">1</span> if <span class=\"tex-span\"><i>k</i></span> floodlight is presented in subset and <span class=\"tex-span\">0</span> if it is not, i.e. so named binary mask.</p><p>For example, <span class=\"tex-span\"><i>dp</i>[6]</span> — (<span class=\"tex-span\">6</span> — <span class=\"tex-span\">110<sub class=\"lower-index\">2</sub></span>) is optimal answer for subset from <span class=\"tex-span\">2</span> and <span class=\"tex-span\">3</span> floodlight.</p><p>Now, let's look through subsets <span class=\"tex-span\"><i>i</i></span> in <span class=\"tex-span\"><i>dp</i>[<i>i</i>]</span>. In subset <span class=\"tex-span\"><i>i</i></span> let's go through absent floodlights <span class=\"tex-span\"><i>j</i></span> and update result for subset where <span class=\"tex-span\"><i>j</i></span> floodlight is present, i.e. dp[ <span class=\"tex-span\"><i>i</i></span> or <span class=\"tex-span\">2<sup class=\"upper-index\"><i>j</i></sup></span> ] = max(dp[ <span class=\"tex-span\"><i>i</i></span> or <span class=\"tex-span\">2<sup class=\"upper-index\"><i>j</i></sup></span>], dp[ <span class=\"tex-span\"><i>i</i></span> ] + calc_rightmost_lighted_point() ). As we can calculate rightmost lighted point, so updating of answer shouldn't be a problem.</p><p><a href=\"/contest/385/problem/E\" title=\"Codeforces Round 226 (Div. 2)\">385E - Bear in the Field</a></p><p>In this task there are several problems that should be concerned:</p><p>1) Simple modeling of bear movement would cause TLE due to <span class=\"tex-span\"><i>t</i></span> <span class=\"tex-span\"> ≤ </span> <span class=\"tex-span\">10<sup class=\"upper-index\">18</sup></span>.</p><p>2) Task can't be solved by separating <span class=\"tex-span\"><i>x</i></span> and <span class=\"tex-span\"><i>y</i></span> axes because <span class=\"tex-span\"><i>x</i></span> and <span class=\"tex-span\"><i>y</i></span> depends on each other.</p><p>3) Also, we can't use standart method of cycle finding via modeling for a short time and checking on collisions because coordinates limitations are very large.</p><p>Let's say we have matrix <span class=\"tex-span\">(<i>x</i><sub class=\"lower-index\"><i>i</i></sub>, <i>y</i><sub class=\"lower-index\"><i>i</i></sub>, <i>dx</i><sub class=\"lower-index\"><i>i</i></sub>, <i>dy</i><sub class=\"lower-index\"><i>i</i></sub>, <i>t</i><sub class=\"lower-index\"><i>i</i></sub>, 1)</span>.</p><p>If we multiply previous matrix by following matrix long long base[6][6] = {</p><p>{2,1,1,1,0,0},</p><p>{1,2,1,1,0,0},</p><p>{1,0,1,0,0,0},</p><p>{0,1,0,1,0,0},</p><p>{0,0,1,1,1,0},</p><p>{0,0,2,2,1,1} };</p><p>we will have get parameters on next step.</p><p>Where did the matrix? Let us write out how to change parameters with each step and see the similarity matrix.</p><p><span class=\"tex-span\"><i>x</i></span> = <span class=\"tex-span\">2·<i>x</i></span> + <span class=\"tex-span\">1·<i>y</i></span> + <span class=\"tex-span\">1·<i>dx</i></span> + <span class=\"tex-span\">0·<i>dy</i></span> + <span class=\"tex-span\">0·<i>t</i></span> + <span class=\"tex-span\">0·1</span>.</p><p><span class=\"tex-span\"><i>y</i></span> = <span class=\"tex-span\">1·<i>x</i></span> + <span class=\"tex-span\">2·<i>y</i></span> + <span class=\"tex-span\">0·<i>dx</i></span> + <span class=\"tex-span\">1·<i>dy</i></span> + <span class=\"tex-span\">0·<i>t</i></span> + <span class=\"tex-span\">0·1</span>.</p><p><span class=\"tex-span\"><i>dx</i></span> = <span class=\"tex-span\">1·<i>x</i></span> + <span class=\"tex-span\">1·<i>y</i></span> + <span class=\"tex-span\">1·<i>dx</i></span> + <span class=\"tex-span\">0·<i>dy</i></span> + <span class=\"tex-span\">1·<i>t</i></span> + <span class=\"tex-span\">2·1</span>.</p><p><span class=\"tex-span\"><i>dy</i></span> = <span class=\"tex-span\">1·<i>x</i></span> + <span class=\"tex-span\">1·<i>y</i></span> + <span class=\"tex-span\">0·<i>dx</i></span> + <span class=\"tex-span\">1·<i>dy</i></span> + <span class=\"tex-span\">1·<i>t</i></span> + <span class=\"tex-span\">2·1</span>.</p><p><span class=\"tex-span\"><i>t</i></span> = <span class=\"tex-span\">0·<i>x</i></span> + <span class=\"tex-span\">0·<i>y</i></span> + <span class=\"tex-span\">0·<i>dx</i></span> + <span class=\"tex-span\">0·<i>dy</i></span> + <span class=\"tex-span\">1·<i>t</i></span> + <span class=\"tex-span\">1·1</span>.</p><p><span class=\"tex-span\">1</span> = <span class=\"tex-span\">0·<i>x</i></span> + <span class=\"tex-span\">0·<i>y</i></span> + <span class=\"tex-span\">0·<i>dx</i></span> + <span class=\"tex-span\">0·<i>dy</i></span> + <span class=\"tex-span\">0·<i>t</i></span> + <span class=\"tex-span\">1·1</span>.</p><p>So if we calculate <span class=\"tex-span\"><i>t</i> - 1</span> power of <span class=\"tex-span\"><i>base</i></span> and then multiply <span class=\"tex-span\">(<i>sx</i>, <i>sy</i>, <i>dx</i>, <i>dy</i>, <i>t</i>, 1)</span> by it we will calculate parameters at moment <span class=\"tex-span\"><i>t</i></span>.</p><p>Power of matrix can be calculated via binary power modulo algo due to associativity of matrix multiplication. More info at <a href=\"http://e-maxx.ru/algo/binary_pow\">http://e-maxx.ru/algo/binary_pow</a></p><p>Using trivial matrix multiplication algo we will solve this task in time proportional <span class=\"tex-span\">6<sup class=\"upper-index\">3</sup>·<i>log</i>(<i>t</i>)</span>.</p></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/385\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 226 (Div. 2)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-2930-10569\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"2930\",\n blogEntryId: \"10514\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-10569\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+85</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-10569\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/CleRIC\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/CleRIC\">\n CleRIC\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Jan/23/2014 19:33\">10 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/10514#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/10514#comments\">\n 30\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"10585\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (25)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158988\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/OpalDshawn\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/40047/avatar/c26edf07c13c133a.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/OpalDshawn\" title=\"Master OpalDshawn\" class=\"rated-user user-orange\">OpalDshawn</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2014 22:59\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158988\" href=\"?#comment-158988\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"158988\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"158988\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"40047\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158988\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Great Editorial!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158988 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158988 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158988\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159026\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Xellos\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/69675/avatar/8526bcfc8e687b43.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/Xellos\" title=\"International Grandmaster Xellos\" class=\"rated-user user-red\">Xellos</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/25/2014 02:06\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159026\" href=\"?#comment-159026\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"159026\" revisionCount=\"7\" revision=\"7\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">7</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"159026\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"28\"\r\n data-commentUserId=\"69675\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+28</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159026\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I solved E (theoretically, I don't really want to implement it) by solving the system of equations:</p> <center><span class=\"tex-span\"><i>x</i>(<i>t</i>) = [<i>x</i>(<i>t</i> - 1) + <i>v</i><sub class=\"lower-index\"><i>x</i></sub>(<i>t</i>) - 1]%<i>N</i> + 1</span></center> <center><span class=\"tex-span\"><i>y</i>(<i>t</i>) = [<i>y</i>(<i>t</i> - 1) + <i>v</i><sub class=\"lower-index\"><i>y</i></sub>(<i>t</i>) - 1]%<i>N</i> + 1</span></center> <center><span class=\"tex-span\"><i>v</i><sub class=\"lower-index\"><i>x</i></sub>(<i>t</i>) = <i>v</i><sub class=\"lower-index\"><i>x</i></sub>(<i>t</i> - 1) + <i>t</i> - 1 + <i>x</i>(<i>t</i> - 1) + <i>y</i>(<i>t</i> - 1)</span></center> <center><span class=\"tex-span\"><i>v</i><sub class=\"lower-index\"><i>y</i></sub>(<i>t</i>) = <i>v</i><sub class=\"lower-index\"><i>y</i></sub>(<i>t</i> - 1) + <i>t</i> - 1 + <i>x</i>(<i>t</i> - 1) + <i>y</i>(<i>t</i> - 1)</span></center><p>for $t > 0$, where the values of <span class=\"tex-span\">(<i>x</i>, <i>y</i>, <i>v</i><sub class=\"lower-index\"><i>x</i></sub>, <i>v</i><sub class=\"lower-index\"><i>y</i></sub>)(0)</span> are given as input parameters, and the time is 0-based.</p><p>Firstly, we want to get rid of the modulo function. We can't just compute all variables modulo <span class=\"tex-span\"><i>N</i></span>, because there's the -1, so we'll shift the coordinates to <span class=\"tex-span\">(<i>x</i>', <i>y</i>')(<i>t</i>)</span>, where <span class=\"tex-span\"><i>x</i>' = <i>x</i> - 1</span>, <span class=\"tex-span\"><i>y</i>' = <i>y</i> - 1</span>. Now the equations become</p> <center><span class=\"tex-span\"><i>x</i>'(<i>t</i>) = <i>x</i>'(<i>t</i> - 1) + <i>v</i><sub class=\"lower-index\"><i>x</i></sub>(<i>t</i>)</span></center> <center><span class=\"tex-span\"><i>y</i>'(<i>t</i>) = <i>y</i>'(<i>t</i> - 1) + <i>v</i><sub class=\"lower-index\"><i>y</i></sub>(<i>t</i>)</span></center> <center><span class=\"tex-span\"><i>v</i><sub class=\"lower-index\"><i>x</i></sub>(<i>t</i>) = <i>v</i><sub class=\"lower-index\"><i>x</i></sub>(<i>t</i> - 1) + <i>t</i> + 1 + <i>x</i>'(<i>t</i> - 1) + <i>y</i>'(<i>t</i> - 1)</span></center> <center><span class=\"tex-span\"><i>v</i><sub class=\"lower-index\"><i>y</i></sub>(<i>t</i>) = <i>v</i><sub class=\"lower-index\"><i>y</i></sub>(<i>t</i> - 1) + <i>t</i> + 1 + <i>x</i>'(<i>t</i> - 1) + <i>y</i>'(<i>t</i> - 1)</span></center><p>where all variables are computed modulo $N$ (we'll omit that from now on). We can compute <span class=\"tex-span\">(<i>x</i>, <i>y</i>, <i>v</i><sub class=\"lower-index\"><i>x</i></sub>, <i>v</i><sub class=\"lower-index\"><i>y</i></sub>)(1)</span> from this, and further substitute for <span class=\"tex-span\"><i>v</i><sub class=\"lower-index\"><i>x</i></sub>, <i>v</i><sub class=\"lower-index\"><i>y</i></sub></span>, which gives for <span class=\"tex-span\"><i>t</i> > 1</span></p> <center><span class=\"tex-span\"><i>x</i>'(<i>t</i>) - <i>x</i>'(<i>t</i> - 1) = <i>x</i>'(<i>t</i> - 1) - <i>x</i>'(<i>t</i> - 2) + <i>t</i> + 1 + <i>x</i>'(<i>t</i> - 1) + <i>y</i>'(<i>t</i> - 1)</span></center> <center><span class=\"tex-span\"><i>y</i>'(<i>t</i>) - <i>y</i>'(<i>t</i> - 1) = <i>y</i>'(<i>t</i> - 1) - <i>y</i>'(<i>t</i> - 2) + <i>t</i> + 1 + <i>x</i>'(<i>t</i> - 1) + <i>y</i>'(<i>t</i> - 1)</span></center><p>Let's now define</p> <center><span class=\"tex-span\"><i>s</i>(<i>t</i>) = <i>x</i>'(<i>t</i>) + <i>y</i>'(<i>t</i>)</span></center> <center><span class=\"tex-span\"><i>d</i>(<i>t</i>) = <i>x</i>'(<i>t</i>) - <i>y</i>'(<i>t</i>)</span></center><p>using which we can rewrite the sum and difference of the equations above to</p> <center><span class=\"tex-span\"><i>d</i>(<i>t</i>) - <i>d</i>(<i>t</i> - 1) = <i>d</i>(<i>t</i> - 1) - <i>d</i>(<i>t</i> - 2)</span></center> <center><span class=\"tex-span\"><i>s</i>(<i>t</i>) - <i>s</i>(<i>t</i> - 1) = <i>s</i>(<i>t</i> - 1) - <i>s</i>(<i>t</i> - 2) + 2(<i>t</i> + 1) + 2<i>s</i>(<i>t</i> - 1)</span></center><p>Once again, we define $q(t)=s(t)+t+2$ (actually, it's <span class=\"tex-span\"><i>s</i>(<i>t</i>) + <i>t</i> + <i>c</i></span>, and we compute the constant <span class=\"tex-span\"><i>c</i></span> by substituting and trying to get the constant term to 0), and rewrite our equations to</p> <center><span class=\"tex-span\"><i>d</i>(<i>t</i>) = 2<i>d</i>(<i>t</i> - 1) - <i>d</i>(<i>t</i> - 2)</span></center> <center><span class=\"tex-span\"><i>q</i>(<i>t</i>) = 4<i>q</i>(<i>t</i> - 1) - <i>q</i>(<i>t</i> - 2)</span></center><p>which can be solved explicitly (I'm lazy, so I'm just using Wolfram Alpha, read more about linear recurrent equations on Wikipedia or something):</p> <center><img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/5ec2a1c8cb9dd5c6d22e9c89f85ea721c45a9659.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></center> <center><span class=\"tex-span\"><i>d</i>(<i>t</i>) = <i>C</i> * <i>t</i> + <i>D</i></span></center><p>where the parameters $A..D$ are given by the values for <span class=\"tex-span\"><i>t</i> ≤ 1</span>.</p><p>This is more of a theoretical solution (since as long as we get the recurrences for <span class=\"tex-span\"><i>d</i>(<i>t</i>)</span> and <span class=\"tex-span\"><i>q</i>(<i>t</i>)</span>, it's best to use matrix multiplication), but I just wanted to do it this way :D</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159026 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159026 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159026\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159027\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/bilalyasar\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/88216/avatar/25c063de47c0f66a.jpg'/> </a>\n <div><a href=\"/profile/bilalyasar\" title=\"Expert bilalyasar\" class=\"rated-user user-blue\">bilalyasar</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/25/2014 03:59\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159027\" href=\"?#comment-159027\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"159027\" revisionCount=\"23\" revision=\"23\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">23</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"159027\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"88216\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159027\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>i think the matrix should be that: {2,1,1,1,0,0},</p><p>{1,2,1,1,0,0},</p><p>{1,0,1,0,0,0},</p><p>{0,1,0,1,0,0},</p><p>{0,0,1,1,1,0},</p><p>{0,0,0,0,1,1} };</p><p>i tried and solved it. with this matrix.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159027 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159027 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159027\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159144\" commentParentId=\"159027\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Amir.bh\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/29435/avatar/84331c66da301d6d.jpg'/> </a>\n <div><a href=\"/profile/Amir.bh\" title=\"Candidate Master Amir.bh\" class=\"rated-user user-violet\">Amir.bh</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/26/2014 15:32\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159144\" href=\"?#comment-159144\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159027\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159144\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"29435\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159144\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Rev. 23????! How could this happen?! :D</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159144 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159144 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159144\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159162\" commentParentId=\"159144\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Xellos\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/69675/avatar/8526bcfc8e687b43.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/Xellos\" title=\"International Grandmaster Xellos\" class=\"rated-user user-red\">Xellos</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/26/2014 17:13\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159162\" href=\"?#comment-159162\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159144\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159162\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"69675\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159162\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Maybe for the same reason as rev.7 of my comment above — I edit my comment, click "Save", nothing happens; I wait until my internet connection is stronger, click again, and nothing happens again, etc., until I lose patience and reload the page. And look what happened: the revisions were counted, but my comment wasn't edited. Some bug of CF, maybe.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159162 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159162 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159162\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159054\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/llaki\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/24382/avatar/6683eebf7eea08ec.jpg'/> </a>\n <div><a href=\"/profile/llaki\" title=\"Expert llaki\" class=\"rated-user user-blue\">llaki</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/25/2014 15:18\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159054\" href=\"?#comment-159054\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159054\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"24382\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159054\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Nice editorial. Anyways, I had a sense that explanation of problem E does not give you an idea of how you can come up with that solution. Let me clarify that: The state can be described by following variables: x — where is the bear currently (x-coordinate); y — where is the bear currently (y-coordinate); dx — the current speed towards X axis; dy — the current speed towards Y axis; t — time passed after the start;</p><p>This information is enough to describe a state. Now let's see how the state changes: (dx)' = dx + (x+y+t), (dy)' = dy+(x+y+t), (x)' = x + (dx)' = 2x+y+dx+t, (y)'=x+2y+dy+t, (t)'= t+1.</p><p>As we see, the new state is similar to linear combination of previous state components, except for t=t+1 (1 is not in a state). It is very similar to matrix multiplication, except for we don't have 1. So we can make a matrix this way: Let's say the state is (1x6) matrix : (x, y, dx, dy, t, 1) and the matrix (M) is 100001 021110 012110 010100 001010 011111 It's easy to see why the new state is the old state matrix multiplied by M. The rest is easy, our final state is going to be the initial state matrix multiplied by the T-th power of M. Of course we're gonna use the fast exponentiation. (The naive multiplication is fine here, because the sizes are too small)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159054 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159054 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159054\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159061\" commentParentId=\"159054\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/KKpoker\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/120167/avatar/297c9d6f6c6672be.jpg'/> </a>\n <div><a href=\"/profile/KKpoker\" title=\"Specialist KKpoker\" class=\"rated-user user-cyan\">KKpoker</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/25/2014 16:34\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159061\" href=\"?#comment-159061\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159054\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"159061\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"159061\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"4\"\r\n data-commentUserId=\"120167\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+4</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159061\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>thx a lot ~ during the exam i think the raspberry will be eaten all , then the number will change from x+y-->1 a silly misunderstanding T_T</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159061 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159061 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159061\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"372356\" commentParentId=\"159054\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/nguyenit67\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/509284/avatar/98668c3aa6c04ca6.jpg'/> </a>\n <div><a href=\"/profile/nguyenit67\" title=\"Pupil nguyenit67\" class=\"rated-user user-green\">nguyenit67</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/11/2017 14:02\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-372356\" href=\"?#comment-372356\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159054\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"372356\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"509284\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-372356\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I'm sorry :) but I don't see why (x)'= x+(dx)'? Could u explain that to me?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-372356 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-372356 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-372356\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"372645\" commentParentId=\"372356\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/nguyenit67\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/509284/avatar/98668c3aa6c04ca6.jpg'/> </a>\n <div><a href=\"/profile/nguyenit67\" title=\"Pupil nguyenit67\" class=\"rated-user user-green\">nguyenit67</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/12/2017 08:25\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-372645\" href=\"?#comment-372645\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-372356\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"372645\" revisionCount=\"4\" revision=\"4\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">4</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"372645\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"509284\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-372645\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Ah</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-372645 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-372645 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-372645\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"372646\" commentParentId=\"159054\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/nguyenit67\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/509284/avatar/98668c3aa6c04ca6.jpg'/> </a>\n <div><a href=\"/profile/nguyenit67\" title=\"Pupil nguyenit67\" class=\"rated-user user-green\">nguyenit67</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/12/2017 08:26\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-372646\" href=\"?#comment-372646\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159054\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"372646\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"509284\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-372646\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Ah now I see it. Thank you for your explanation :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-372646 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-372646 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-372646\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159079\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/MoustafaMaher\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/47658/avatar/48ad52ec2bf89c75.jpg'/> </a>\n <div><a href=\"/profile/MoustafaMaher\" title=\"Candidate Master MoustafaMaher\" class=\"rated-user user-violet\">MoustafaMaher</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/25/2014 19:18\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159079\" href=\"?#comment-159079\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159079\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"47658\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159079\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Problem D !?! </p><p>how u can calculate calc_rightmost_lighted_point() in ur Dp without keeping the last right_most_point u can get till before this state </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159079 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159079 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159079\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159093\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Lord_F\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/41018/avatar/1e2b817ca83c107e.jpg'/> </a>\n <div><a href=\"/profile/Lord_F\" title=\"Candidate Master Lord_F\" class=\"rated-user user-violet\">Lord_F</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/25/2014 21:37\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159093\" href=\"?#comment-159093\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"159093\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"159093\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"41018\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159093\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>By the way, in problem D you can use law of sines to find the distance that is lighted with some floodlight.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159093 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159093 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159093\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159105\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/-emli-\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/29285/avatar/9fa3a36fa8f9d060.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/-emli-\" title=\"Pupil -emli-\" class=\"rated-user user-green\">-emli-</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/25/2014 23:59\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159105\" href=\"?#comment-159105\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159105\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"29285\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159105\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In problem C , i can't understand why we add pre[i-1] to pre[i]?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159105 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159105 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159105\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159109\" commentParentId=\"159105\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/piotreekw\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/piotreekw\" title=\"Specialist piotreekw\" class=\"rated-user user-cyan\">piotreekw</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/26/2014 00:51\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159109\" href=\"?#comment-159109\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159105\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159109\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"151924\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159109\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>If you iterate i from 2 to n-1 adding pre[i-1] to pre[i], every new pre[i] will contain sum of all pre from 1 to i</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159109 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159109 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159109\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159126\" commentParentId=\"159109\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/-emli-\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/29285/avatar/9fa3a36fa8f9d060.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/-emli-\" title=\"Pupil -emli-\" class=\"rated-user user-green\">-emli-</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/26/2014 09:24\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159126\" href=\"?#comment-159126\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159109\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159126\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"29285\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159126\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thank you! one more question how to prove that pre[r]-pre[l-1] is answer of query?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159126 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159126 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159126\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159129\" commentParentId=\"159126\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ReekinAcer\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/ReekinAcer\" title=\"Expert ReekinAcer\" class=\"rated-user user-blue\">ReekinAcer</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/26/2014 12:01\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159129\" href=\"?#comment-159129\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159126\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159129\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"106426\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159129\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I think it is clearer if we denote Cnt[i] = f(i) and Sum[i] = Cnt[1] + Cnt[2] + ... + Cnt[i]. Now, the answer for a query on [l, r] is Sum[r]-Sum[l-1].</p><p>Sum[r]-Sum[l-1] = (Cnt[1] + Cnt[2] + ... + Cnt[r])-(Cnt[1] + Cnt[2] + ... + Cnt[l-1]) = [(Cnt[1] + ... + Cnt[l-1]) + (Cnt[l] + Cnt[l + 1] + ... + Cnt[r])] — (Cnt[1] + ... + Cnt[l-1]) = Cnt[l] + Cnt[l + 1] + ... + Cnt[r].</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159129 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159129 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159129\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"211346\" commentParentId=\"159105\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/G_Hani\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/119692/avatar/ea9b44051a710c1b.jpg'/> </a>\n <div><a href=\"/profile/G_Hani\" title=\"Specialist G_Hani\" class=\"rated-user user-cyan\">G_Hani</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/06/2015 00:49\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-211346\" href=\"?#comment-211346\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159105\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"211346\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"119692\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-211346\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p><a class=\"rated-user user-green\" href=\"/profile/-emli-\" title=\"Pupil -emli-\">-emli-</a> <a class=\"rated-user user-blue\" href=\"/profile/ReekinAcer\" title=\"Expert ReekinAcer\">ReekinAcer</a> can u help me please. here my code for C and get WA at tc 4 !! <a href=\"/contest/385/submission/9731769\" title=\"Submission 9731769 by G_Hani\">9731769</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-211346 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-211346 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-211346\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159138\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/shubh09\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/shubh09\" title=\"Expert shubh09\" class=\"rated-user user-blue\">shubh09</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/26/2014 13:36\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159138\" href=\"?#comment-159138\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159138\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"72364\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159138\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Nice editorial! But I suppose that a link to a solution implementing the idea outlined in the editorial for every question would help us understand them even better!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159138 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159138 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159138\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159141\" commentParentId=\"159138\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Lord_F\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/41018/avatar/1e2b817ca83c107e.jpg'/> </a>\n <div><a href=\"/profile/Lord_F\" title=\"Candidate Master Lord_F\" class=\"rated-user user-violet\">Lord_F</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/26/2014 14:13\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159141\" href=\"?#comment-159141\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159138\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"159141\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"159141\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"41018\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159141\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Well, you can use "Status filter"</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159141 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159141 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159141\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159178\" commentParentId=\"159141\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/shubh09\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/shubh09\" title=\"Expert shubh09\" class=\"rated-user user-blue\">shubh09</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/26/2014 18:14\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159178\" href=\"?#comment-159178\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159141\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159178\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"72364\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159178\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Well, not all the accepted solutions use the idea mentioned in the editorials. It's a bit inconvenient browsing through all accepted solutions to find the one which does.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159178 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159178 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159178\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"330629\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/adityagupta1089\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/337877/avatar/e2156094910d501.jpg'/> </a>\n <div><a href=\"/profile/adityagupta1089\" title=\"Expert adityagupta1089\" class=\"rated-user user-blue\">adityagupta1089</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Dec/14/2016 22:58\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-330629\" href=\"?#comment-330629\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"330629\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"330629\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"337877\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-330629\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In problem C, I did made a cnt array (or say a hashmap) and did find all primes below the maximum x using Sieve of Erathosthenes, then for each prime I iterated over every number and and found f(p) and stored them in a Binary Index Tree, but that didn't help. I believe my complexity is O(n(logn)(loglogn)+m(logn+logP)+PlogP) where P(664,579~10^7) is the count of primes below maximum x so total operations are around 5e6+6e7+4e7 but it has a TLE?.<a href=\"//codeforces.com/contest/385/submission/22981801\">This</a> is my submission.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-330629 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-330629 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-330629\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"587392\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/reet_bhaati\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1176149/avatar/7f68facc9bda856e.jpg'/> </a>\n <div><a href=\"/profile/reet_bhaati\" title=\"Specialist reet_bhaati\" class=\"rated-user user-cyan\">reet_bhaati</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/10/2020 10:46\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-587392\" href=\"?#comment-587392\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"587392\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"-8\"\r\n data-commentUserId=\"1176149\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-587392\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>can anyone help me out? I have tried 385C and it gives me a runtime error on test case 4 link to my code — <a href=\"https://ideone.com/fork/GMagWh\">https://ideone.com/fork/GMagWh</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-587392 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-587392 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-587392\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"642670\" commentParentId=\"587392\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/back_to_code\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1292092/avatar/b57b403a9af2ef26.jpg'/> </a>\n <div><a href=\"/profile/back_to_code\" title=\"Specialist back_to_code\" class=\"rated-user user-cyan\">back_to_code</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/15/2020 21:38\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-642670\" href=\"?#comment-642670\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-587392\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"642670\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"642670\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1292092\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-642670\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I don't know if you are still looking for this :</p><p>That might be because x or y i.e the query ranges might be going out of limits. Also it may help the others who attempt it.</p><p>Edit : Also if anyone is getting TLE even after implementing same approach use:</p> <pre><code>ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);\n</code></pre></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-642670 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-642670 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-642670\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"658423\" commentParentId=\"587392\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/apoorva222g\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1213778/avatar/2153e9cce1fd37f.jpg'/> </a>\n <div><a href=\"/profile/apoorva222g\" title=\"Expert apoorva222g\" class=\"rated-user user-blue\">apoorva222g</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/09/2020 11:58\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-658423\" href=\"?#comment-658423\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-587392\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"658423\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1213778\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-658423\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Reduce any l or r to 10^7 if it is greater than 10^7. Try this case 1 2000 1 1424767024 1629755604</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-658423 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-658423 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-658423\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"686007\" commentParentId=\"658423\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/y0g38h_kum4r\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1561883/avatar/5594dfbdb87a226d.jpg'/> </a>\n <div><a href=\"/profile/y0g38h_kum4r\" title=\"Expert y0g38h_kum4r\" class=\"rated-user user-blue\">y0g38h_kum4r</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/25/2020 02:40\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-686007\" href=\"?#comment-686007\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-658423\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"686007\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1561883\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-686007\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>OH! thanks a lot for this test case!!!!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-686007 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-686007 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-686007\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n <br/>\r\n\r\n<div id=\"editBox-10585\" style=\"width:50em;display:none;\">\r\n <div class=\"previewBody\" style=\"border: 1px solid #d4d4d4; margin-bottom: 0.5em; padding: 0.25em; display:none;\"> </div>\r\n <div style=\"width: 1px\"> </div>\r\n <div class=\"commentLocale\" style=\"position: relative; top: 0.5em;left:4px;display: none;\">\r\n <input type=\"radio\" name=\"locale\" value=\"en\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In English</span>\r\n <input style=\"margin-left:1em\" type=\"radio\" name=\"locale\" value=\"ru\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In Russian</span>\r\n </div>\r\n <textarea data-drafts-id=\"CommentReplyFrame\" class=\"wysiwyg\" name=\"editContent\" rows=\"20\" style=\"width:99%;\"></textarea>\r\n <div class=\"error error__content\"></div>\r\n <div style=\"text-align:center;\">\r\n <input type=\"button\" name=\"preview\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Preview\"/>\r\n <input type=\"button\" name=\"save\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Save\"/>\r\n </div>\r\n</div>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n\r\nvar firstPreview10585 = true;\r\nvar lastPreviewContent10585 = '';\r\n\r\nif (!window.moveCommentRevision) {\r\n moveCommentRevision = function(e, dir) {\r\n var p = e.parent();\r\n var revisionCount = parseInt(p.attr(\"revisionCount\"));\r\n var revision = parseInt(p.attr(\"revision\"));\r\n var next = revision + dir;\r\n var commentId = p.attr(\"commentId\");\r\n if (next >= 1 && next <= revisionCount) {\r\n $.post(\r\n \"/data/comment-data\",\r\n {action: \"revision\", commentId: commentId, revision: next},\r\n function(json) {\r\n if (json.success == \"true\") {\r\n var parentDiv = e;\r\n\r\n while (parentDiv !== null && (parentDiv[0].nodeName.toLowerCase() !== \"td\" || !parentDiv.hasClass(\"right\"))) {\r\n parentDiv = parentDiv.parent();\r\n }\r\n\r\n if (parentDiv === null) {\r\n return;\r\n }\r\n\r\n parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\").html(json.content);\r\n Codeforces.setupSpoilers(parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\"));\r\n p.attr(\"revision\", next);\r\n p.find(\"span.revision\").text(next);\r\n if (next == 1) {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"visible\");\r\n }\r\n if (next == revisionCount) {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"visible\");\r\n }\r\n\r\n window.updateTypography();\r\n MathJax.Hub.Typeset();\r\n } else {\r\n alert(e.error);\r\n }\r\n },\r\n \"json\"\r\n );\r\n }\r\n };\r\n}\r\n\r\n$(\"div[commentableId=10585] a.leftRevision\").click(function () {\r\n window.moveCommentRevision($(this), -1);\r\n return false;\r\n});\r\n\r\n$(\"div[commentableId=10585] a.rightRevision\").click(function () {\r\n window.moveCommentRevision($(this), +1);\r\n return false;\r\n});\r\n\r\n\r\n\r\n });\n </script>\n\r\n\r\n <script src=\"//codeforces.org/s/81027/js/swfobject-2.2.min.js\" type=\"text/javascript\"></script>\n <script src=\"//codeforces.org/s/81027/js/ftaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n if (window.evercookie) {\n var ec = new evercookie({\n history: false,\n silverlight: false,\n baseurl: '',\n asseturi: '/assets',\n phpuri: '/2fdcd78',\n pngPath: '/eps',\n etagPath: '/ees',\n cachePath: '/ecs'\n });\n\n var randomNumber = function () {\n return Math.random().toString(36).substr(2);\n };\n\n var randomToken = function () {\n return (randomNumber() + randomNumber()).substring(0, 18);\n };\n\n window._ftaa = \"\";\n\n ec.get(\"70a7c28f3de\", function (value) {\n window._ftaa = value;\n if (!window._ftaa) {\n window._ftaa = randomToken();\n ec.set(\"70a7c28f3de\", window._ftaa);\n }\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n } else {\n window._ftaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\n <script src=\"//codeforces.org/s/81027/js/bfaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n var fpCallback = function() {\n Fingerprint2.get({}, function(components) {\n window._bfaa = Fingerprint2.x64hash128(components.map(function (pair) { return pair.value }).join(), 31);\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n };\n if (typeof Fingerprint2 !== 'undefined') {\n if (window.requestIdleCallback) {\n requestIdleCallback(fpCallback)\n } else {\n setTimeout(fpCallback, 500)\n }\n } else {\n window._bfaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"a.new-root-comment\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n\r\n $(\".comment-table .reply a\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".vote-for-comment\").mouseover(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").mouseout(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").click(function () {\r\n var vote = $(this);\r\n var commentId = $(this).parent().attr(\"commentid\");\r\n var commentRating = $(this).parent().attr(\"data-commentRating\");\r\n var direction = $(this).attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n $.post(\"/data/comment/vote\", {commentId: commentId, _tta: Codeforces.tta(), vote: direction, commentRating: commentRating}, function(data) {\r\n if (direction != 0 && !ownComment && data[\"success\"] == \"true\") {\r\n vote.parent().find(\".vote-for-comment\").attr(\"voteDirection\", 0);\r\n if (direction == 1)\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n else {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.closest(\".CommentVoteFrame\").find(\".ComplaintFrame\").css(\"display\", \"inline-block\");\r\n }\r\n vote.find(\"img\").attr(\"popacity\", \"1.0\");\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n vote.parent().find(\".commentRating\").html(data[\"commentRating\"]);\r\n }\r\n Codeforces.showMessage(data[\"message\"]);\r\n }, \"json\");\r\n return false;\r\n });\r\n\r\n $(\".negative-comment-vote\").closest(\".comment-table\").addClass(\"comment-bad\");\r\n\r\n $(\".troll-comment-vote\").closest(\".comment\").css(\"display\", \"none\");\r\n\r\n $(\".too-negative-comment-vote\").closest(\".comment-table\").each(function () {\r\n var e = $(this);\r\n e.addClass(\"comment-too-bad\");\r\n var commentId = e.attr(\"commentId\");\r\n $(\"<div class='bad-comment-replacement ttypography'>The comment is hidden because of too negative feedback, click <a href=# class=show-bad-comment-link>here</a> to view it</div>\").appendTo(\r\n e.find(\".right\")\r\n );\r\n e.find(\".comment-content\").hide();\r\n e.find(\".show-bad-comment-link\").click(function () {\r\n e.find(\".comment-content\").show();\r\n e.find(\".bad-comment-replacement\").hide();\r\n return false;\r\n });\r\n });\r\n });\n </script>\n </div>\r\n\r\n <style type=\"text/css\">\r\n .new-comments-box {\r\n padding: 0.5em;\r\n width: 22px;\r\n font-size: 1.3rem;\r\n font-weight: bold !important;\r\n\r\n position: fixed;\r\n top: 40%;\r\n right: 0;\r\n opacity: 0.2;\r\n color: white;\r\n text-align: center;\r\n\r\n border: 1px solid #222;\r\n background-color: #888 !important;\r\n border-radius: 3px;\r\n -moz-border-radius: 3px;\r\n -webkit-border-radius: 3px;\r\n }\r\n\r\n .new-comments-box:hover {\r\n opacity: 1;\r\n }\r\n\r\n .new-comments-box .dir:hover {\r\n background: #3B5998 !important;\r\n cursor: pointer;\r\n }\r\n </style>\r\n\r\n <div class=\"new-comments-box\" data-position=\"outside\" data-index=\"-1\" style=\"display: none;\">\r\n <div class=\"up dir\" title=\"Ctrl+Up\">↑<hr/>\r\n </div>\r\n <div class=\"info\" title=\"New comments\"></div>\r\n <div class=\"down dir\" title=\"Ctrl+Down\">\r\n <hr/>↓\r\n </div>\r\n </div>\r\n\r\n <script>\r\n $(\".show-archived-checkbox\").change(function () {\r\n const checked = $(this).is(\":checked\");\r\n $.post(\"/data/comment-data\", {action: \"setShowArchived\", checked}, function (json) {\r\n if (json[\"success\"] !== \"true\") {\r\n alert(json[\"error\"]);\r\n } else {\r\n if (checked) {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are now displayed\")\r\n } else {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are no longer displayed\")\r\n }\r\n }\r\n });\r\n return false;\r\n });\r\n\r\n function gotoComment(direction) {\r\n var box = $(\".new-comments-box\");\r\n var index = parseInt(box.attr(\"data-index\"));\r\n if (index == -1)\r\n index = 0;\r\n else\r\n index = Math.max(0, Math.min(parseInt(box.find(\".info\").text()) - 1, index + direction));\r\n box.attr(\"data-index\", index);\r\n var comment = $($(\".comment .highlight-blue[commentId]\").get(index));\r\n $('html, body').animate({\r\n 'scrollTop': Math.max(0, comment.offset().top - ($(window).height() - comment.height()) / 2)\r\n });\r\n return false;\r\n }\r\n\r\n $(\".new-comments-box .down\").click(function () {\r\n return gotoComment(1);\r\n });\r\n\r\n $(\".new-comments-box .up\").click(function () {\r\n return gotoComment(-1);\r\n });\r\n\r\n $(document).keydown(function (e) {\r\n var code = (e.keyCode ? e.keyCode : e.which);\r\n if (e.ctrlKey) {\r\n if (code == 38 || code == 40) {\r\n gotoComment(code - 39);\r\n }\r\n }\r\n });\r\n\r\n var newCommentCount = $(\".comment .highlight-blue[commentId]\").length;\r\n if (newCommentCount > 0) {\r\n $(\".new-comments-box .info\").text(newCommentCount);\r\n $(\".new-comments-box\").show();\r\n }\r\n\r\n $('table.comment-table').mouseenter(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").addClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n\r\n $('table.comment-table').mouseleave(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").removeClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n </script>\r\n\r\n\r\n\r\n <script>\r\n function adjustTopicComplainFrames() {\r\n let topicIds = [];\r\n\r\n $(\".has-topic-id\").each(function () {\r\n const $this = $(this);\r\n const topicId = $this.attr(\"topicId\");\r\n if (topicId) {\r\n topicIds.push(topicId);\r\n }\r\n });\r\n\r\n $.post(\"/data/topics\", {\r\n action: \"findComplainableTopicIds\",\r\n topicIds: topicIds.join(\",\")\r\n }, function (json) {\r\n if (json[\"success\"] === \"true\") {\r\n for (const topicId of json[\"complainableTopicIds\"].split(\",\")) {\r\n $(\".has-topic-id[topicId=\" + topicId + \"]\").each(function () {\r\n $(this).find(\".meta .ComplaintFrame\").css(\"display\", \"inline-block\");\r\n });\r\n }\r\n }\r\n }, \"json\");\r\n }\r\n\r\n $(function () {\r\n adjustTopicComplainFrames();\r\n })\r\n </script>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-10569\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 10569, _tta: Codeforces.tta(), topicRevisionId: 36378, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-10569\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 10569, _tta: Codeforces.tta(), topicRevisionId: 36378, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n </div>\r\n </div>\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 22:13:04</span> (h1).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/81027/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/81027/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/81027/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/81027/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-81027.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'8128758f5b7075a7',t:'MTY5NjcwNTk4NC4yOTcwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"}}},{"rowIdx":1946,"cells":{"problem_id":{"kind":"string","value":"385C"},"contest":{"kind":"string","value":"385"},"problem":{"kind":"string","value":"C"},"lang":{"kind":"string","value":"en"},"problem_title":{"kind":"string","value":"C. Bear and Prime Numbers"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">C. Bear and Prime Numbers</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>512 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Recently, the bear started studying data structures and faced the following problem.</p><p>You are given a sequence of integers <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">1</sub>, <i>x</i><sub class=\"lower-index\">2</sub>, ..., <i>x</i><sub class=\"lower-index\"><i>n</i></sub></span> of length <span class=\"tex-span\"><i>n</i></span> and <span class=\"tex-span\"><i>m</i></span> queries, each of them is characterized by two integers <span class=\"tex-span\"><i>l</i><sub class=\"lower-index\"><i>i</i></sub>, <i>r</i><sub class=\"lower-index\"><i>i</i></sub></span>. Let's introduce <span class=\"tex-span\"><i>f</i>(<i>p</i>)</span> to represent the number of such indexes <span class=\"tex-span\"><i>k</i></span>, that <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>k</i></sub></span> is divisible by <span class=\"tex-span\"><i>p</i></span>. The answer to the query <span class=\"tex-span\"><i>l</i><sub class=\"lower-index\"><i>i</i></sub>, <i>r</i><sub class=\"lower-index\"><i>i</i></sub></span> is the sum: <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/5e448f6c1a0e40843cecdbbeb95970464626032f.png\" style=\"max-width: 100.0%;max-height: 100.0%;\"/>, where <span class=\"tex-span\"><i>S</i>(<i>l</i><sub class=\"lower-index\"><i>i</i></sub>, <i>r</i><sub class=\"lower-index\"><i>i</i></sub>)</span> is a set of prime numbers from segment <span class=\"tex-span\">[<i>l</i><sub class=\"lower-index\"><i>i</i></sub>, <i>r</i><sub class=\"lower-index\"><i>i</i></sub>]</span> (both borders are included in the segment).</p><p>Help the bear cope with the problem.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains integer <span class=\"tex-span\"><i>n</i></span> <span class=\"tex-span\">(1 ≤ <i>n</i> ≤ 10<sup class=\"upper-index\">6</sup>)</span>. The second line contains <span class=\"tex-span\"><i>n</i></span> integers <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">1</sub>, <i>x</i><sub class=\"lower-index\">2</sub>, ..., <i>x</i><sub class=\"lower-index\"><i>n</i></sub></span> <span class=\"tex-span\">(2 ≤ <i>x</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 10<sup class=\"upper-index\">7</sup>)</span>. The numbers are not necessarily distinct.</p><p>The third line contains integer <span class=\"tex-span\"><i>m</i></span> <span class=\"tex-span\">(1 ≤ <i>m</i> ≤ 50000)</span>. Each of the following <span class=\"tex-span\"><i>m</i></span> lines contains a pair of space-separated integers, <span class=\"tex-span\"><i>l</i><sub class=\"lower-index\"><i>i</i></sub></span> and <span class=\"tex-span\"><i>r</i><sub class=\"lower-index\"><i>i</i></sub></span> <span class=\"tex-span\">(2 ≤ <i>l</i><sub class=\"lower-index\"><i>i</i></sub> ≤ <i>r</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 2·10<sup class=\"upper-index\">9</sup>)</span> — the numbers that characterize the current query.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print <span class=\"tex-span\"><i>m</i></span> integers — the answers to the queries on the order the queries appear in the input.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>6<br/>5 5 7 10 14 15<br/>3<br/>2 11<br/>3 12<br/>4 4<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>9<br/>7<br/>0<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>7<br/>2 3 5 7 11 4 8<br/>2<br/>8 10<br/>2 123<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>0<br/>7<br/></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>Consider the first sample. Overall, the first sample has 3 queries.</p><ol> <li> The first query <span class=\"tex-span\"><i>l</i> = 2</span>, <span class=\"tex-span\"><i>r</i> = 11</span> comes. You need to count <span class=\"tex-span\"><i>f</i>(2) + <i>f</i>(3) + <i>f</i>(5) + <i>f</i>(7) + <i>f</i>(11) = 2 + 1 + 4 + 2 + 0 = 9</span>. </li><li> The second query comes <span class=\"tex-span\"><i>l</i> = 3</span>, <span class=\"tex-span\"><i>r</i> = 12</span>. You need to count <span class=\"tex-span\"><i>f</i>(3) + <i>f</i>(5) + <i>f</i>(7) + <i>f</i>(11) = 1 + 4 + 2 + 0 = 7</span>. </li><li> The third query comes <span class=\"tex-span\"><i>l</i> = 4</span>, <span class=\"tex-span\"><i>r</i> = 4</span>. As this interval has no prime numbers, then the sum equals 0. </li></ol></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"33b7ecc30f9907cc9d5848d9c5941aed\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - C - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"3200a641fa0ca6f78af7a41b57e5016ab7be9096\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - C - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/73366/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/73366/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/73366/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/73366/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/73366/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/73366/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/73366/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/73366/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/73366/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/73366/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/73366/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/73366/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/73366/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/73366/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/sidebar-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/a037fe51637846d9c7c725713cd840ea/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='33b7ecc30f9907cc9d5848d9c5941aed'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/73366/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/73366/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fcontest%2F385%2Fproblem%2FC%3Flocale%3Den\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"current\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='33b7ecc30f9907cc9d5848d9c5941aed'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:100%;\"><a style=\"color: black\" href=\"/contest/385\">Codeforces Round 226 (Div. 2)</a></th>\n </tr>\n <tr>\n <td class=\"left bottom\" colspan=\"1\"><span class=\"contest-state-phase\">Finished</span></td>\n </tr>\n </tbody>\n </table>\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Practice?\n <div class=\"top-links\">\n </div>\n </div>\n<div>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Want to solve the contest problems after the official contest ends? Just register for practice and you will be able to submit solutions.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"\" method=\"post\"><input type='hidden' name='csrf_token' value='33b7ecc30f9907cc9d5848d9c5941aed'/>\r\n <input type=\"hidden\" name=\"action\" value=\"registerForPractice\"/>\r\n <input type=\"submit\" name=\"submit\" value=\"Register for practice\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div> \r\n</div>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox ContestVirtualFrame borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Virtual participation <i class=\"sidebar-caption-icon las la-angle-down\"></i>\r\n\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\" \"\r\n\r\n data-page-url=\"/data/sidebarFrames\"\r\n\r\n>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests.\n\nIf you've seen these problems, a virtual contest is not for you - solve these problems in the archive.\n\nIf you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.\n\nNever use someone else's code, read the tutorials or communicate with other person during a virtual contest.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"/contest/385/virtual\" method=\"get\">\r\n <input type=\"submit\" name=\"submit\" value=\"Start virtual contest\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div>\r\n</div>\r\n <script>\r\n $(function () {\r\n $(\".ContestVirtualFrame .sidebar-caption-icon\").click(function() {\r\n $(this).toggleClass(\"la-angle-down la-angle-right\");\r\n const $target = $(this).parent().next();\r\n $target.toggle();\r\n const dataPageUrl = $target.attr(\"data-page-url\");\r\n const collapsed = $(this).hasClass(\"la-angle-right\");\r\n const params = {\r\n action: \"setCollapsed\",\r\n sidebarFrameSimpleClassName: \"ContestVirtualFrame\",\r\n collapsed\r\n };\r\n $.each($target[0].attributes, function(i, a) {\r\n const name = a.name;\r\n if (name.startsWith(\"data-extra-key-\")) {\r\n const key = a.value;\r\n const keyIndex = parseInt(name.substring(\"data-extra-key-\".length));\r\n const value = $target.attr(\"data-extra-value-\" + keyIndex);\r\n params[key] = value;\r\n }\r\n });\r\n $.post(dataPageUrl, params, function (result) {\r\n if (result[\"success\"] !== \"true\") {\r\n Codeforces.showMessage(\"Failed to save collapsed state.\");\r\n }\r\n }, \"json\");\r\n return false;\r\n });\r\n })\r\n </script>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Problem tags\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Binary search\">\r\n binary search\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Brute force\">\r\n brute force\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Heaps, binary search trees, segment trees, hash tables, etc\">\r\n data structures\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Dynamic programming\">\r\n dp\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Implementation problems, programming technics, simulation\">\r\n implementation\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Mathematics including integration, differential equations, etc\">\r\n math\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Number theory: Euler function, GCD, divisibility, etc\">\r\n number theory\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Difficulty\">\r\n *1700\r\n</span>\r\n </div>\n <div style=\"clear:both;text-align:right;font-size:1.1rem;\">\r\n <span title=\"Please login into the Codeforces\" class=\"notice\">No tag edit access</span>\r\n </div>\r\n</div>\r\n </div>\n\r\n<form id=\"addTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='33b7ecc30f9907cc9d5848d9c5941aed'/>\r\n <input name=\"action\" type=\"hidden\" value=\"addTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"5933\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<form id=\"removeTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='33b7ecc30f9907cc9d5848d9c5941aed'/>\r\n <input name=\"action\" type=\"hidden\" value=\"removeTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"5933\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<script type=\"text/javascript\">\r\n $(\".tag-box img\").click(function () {\r\n var tagName = $(this).attr(\"value\");\r\n Codeforces.confirm(\"Are you sure you want to remove this tag?\", function () {\r\n $(\"#removeTagForm input[name=tagName]\").val(tagName);\r\n $(\"#removeTagForm\").submit();\r\n }, function () {\r\n }, \"Yes\", \"No\");\r\n });\r\n\r\n $(\"#addTagLink\").click(function () {\r\n $(this).hide();\r\n $(\"#addTagLabel\").show();\r\n return false;\r\n });\r\n\r\n $(\"#addTagSelect\").change(function () {\r\n var tagName = $(this).val();\r\n if (tagName === \"\") {\r\n $(\"#addTagLabel\").hide();\r\n $(\"#addTagLink\").show();\r\n } else {\r\n $(\"#addTagForm input[name=tagName]\").val(tagName);\r\n $(\"#addTagForm\").submit();\r\n }\r\n });\r\n</script>\r\n\r\n<style type=\"text/css\">\r\n#new-resource-form tr td {\r\npadding-top: 0.5em;\r\n}\r\n#new-resource-form input:not([type=\"submit\"]) {\r\nfont-size: 0.8em;\r\n}\r\n#new-resource-form select {\r\nfont-size: 0.8em;\r\n}\r\n.new-resource-error {\r\nfont-size: 0.8em;\r\n}\r\n.resource-locale {\r\ncolor: #666;\r\nfont-family: Consolas, \"Andale Mono WT\", \"Andale Mono\", \"Lucida Console\", \"Lucida Sans Typewriter\", \"DejaVu Sans Mono\", \"Bitstream Vera Sans Mono\", \"Liberation Mono\", \"Nimbus Mono L\", Monaco, \"Courier New\", Courier, monospace;\r\n}\r\n</style>\r\n<div class=\"roundbox sidebox sidebar-menu borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Contest materials\n<div class=\"top-links\">\n</div>\n</div>\n<ul>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/10512\" title=\"Codeforces Round #226 (Div. 2)\" target=\"_blank\">Announcement</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"2193:2194\" resourceName=\"Announcement\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/10514\" title=\"Codeforces Round #226 (Div. 2) — Editorial\" target=\"_blank\">Tutorial</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"2197:2198\" resourceName=\"Tutorial\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n</ul>\r\n</div></div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li class=\"current selectedLava\"><a\r\n href=\"/contest/385\">Problems</a></li>\r\n <li><a\r\n href=\"/contest/385/submit\">Submit Code</a></li>\r\n <li><a\r\n href=\"/contest/385/my\">My Submissions</a></li>\r\n <li><a\r\n href=\"/contest/385/status\">Status</a></li>\r\n <li><a\r\n href=\"/contest/385/hacks\">Hacks</a></li>\r\n <li><a\r\n href=\"/contest/385/room/1\">Room</a></li>\r\n <li><a\r\n href=\"/contest/385/standings\">Standings</a></li>\r\n <li><a\r\n href=\"/contest/385/customtest\">Custom Invocation</a></li>\r\n</ul>\r\n</div>\n\r\n <style>\r\n #facebox .content:has(.diff-popup) {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n }\r\n\r\n .testCaseMarker {\r\n position: absolute;\r\n font-weight: bold;\r\n font-size: 1rem;\r\n }\r\n\r\n .diff-popup {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n display: none;\r\n overflow: auto;\r\n }\r\n\r\n .input-output-copier {\r\n font-size: 1.2rem;\r\n float: right;\r\n color: #888 !important;\r\n cursor: pointer;\r\n border: 1px solid rgb(185, 185, 185);\r\n padding: 3px;\r\n margin: 1px;\r\n line-height: 1.1rem;\r\n text-transform: none;\r\n }\r\n\r\n .input-output-copier:hover {\r\n background-color: #def;\r\n }\r\n\r\n .test-explanation textarea {\r\n width: 100%;\r\n height: 1.5em;\r\n }\r\n\r\n .pending-submission-message {\r\n color: darkorange !important;\r\n }\r\n </style>\r\n <script>\r\n const OPENING_SPACE = String.fromCharCode(1001);\r\n const CLOSING_SPACE = String.fromCharCode(1002);\r\n\r\n const nodeToText = function (node, pre) {\r\n let result = [];\r\n\r\n if (node.tagName === \"SCRIPT\" || node.tagName === \"math\"\r\n || (node.classList && node.classList.contains(\"input-output-copier\")))\r\n return [];\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(OPENING_SPACE);\r\n }\r\n\r\n if (node.nodeType === Node.TEXT_NODE) {\r\n let s = node.textContent;\r\n if (!pre) {\r\n s = s.replace(/\\s+/g, \" \");\r\n }\r\n if (s.length > 0) {\r\n result.push(s);\r\n }\r\n }\r\n\r\n if (pre && node.tagName === \"BR\") {\r\n result.push(\"\\n\");\r\n }\r\n\r\n node.childNodes.forEach(function (child) {\r\n result.push(nodeToText(child, node.tagName === \"PRE\").join(\"\"));\r\n });\r\n\r\n if (node.tagName === \"DIV\"\r\n || node.tagName === \"P\"\r\n || node.tagName === \"PRE\"\r\n || node.tagName === \"UL\"\r\n || node.tagName === \"LI\"\r\n ) {\r\n result.push(\"\\n\");\r\n }\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(CLOSING_SPACE);\r\n }\r\n\r\n return result;\r\n }\r\n\r\n const isSpecial = function (c) {\r\n return c === ',' || c === '.' || c === ';' || c === ')' || c === ' ';\r\n }\r\n\r\n const convertStatementToText = function(statmentNode) {\r\n const text = nodeToText(statmentNode, false).join(\"\").replace(/ +/g, \" \").replace(/\\n\\n+/g, \"\\n\\n\");\r\n let result = [];\r\n for (let i = 0; i < text.length; i++) {\r\n const c = text.charAt(i);\r\n if (c === OPENING_SPACE) {\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"C\" data-uuid=\"ps_0d0af58821ab648c99b83cddb68503d247017e32\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">C. Bear and Prime Numbers</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>512 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Recently, the bear started studying data structures and faced the following problem.</p><p>You are given a sequence of integers <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">1</sub>, <i>x</i><sub class=\"lower-index\">2</sub>, ..., <i>x</i><sub class=\"lower-index\"><i>n</i></sub></span> of length <span class=\"tex-span\"><i>n</i></span> and <span class=\"tex-span\"><i>m</i></span> queries, each of them is characterized by two integers <span class=\"tex-span\"><i>l</i><sub class=\"lower-index\"><i>i</i></sub>, <i>r</i><sub class=\"lower-index\"><i>i</i></sub></span>. Let's introduce <span class=\"tex-span\"><i>f</i>(<i>p</i>)</span> to represent the number of such indexes <span class=\"tex-span\"><i>k</i></span>, that <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>k</i></sub></span> is divisible by <span class=\"tex-span\"><i>p</i></span>. The answer to the query <span class=\"tex-span\"><i>l</i><sub class=\"lower-index\"><i>i</i></sub>, <i>r</i><sub class=\"lower-index\"><i>i</i></sub></span> is the sum: <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/5e448f6c1a0e40843cecdbbeb95970464626032f.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />, where <span class=\"tex-span\"><i>S</i>(<i>l</i><sub class=\"lower-index\"><i>i</i></sub>, <i>r</i><sub class=\"lower-index\"><i>i</i></sub>)</span> is a set of prime numbers from segment <span class=\"tex-span\">[<i>l</i><sub class=\"lower-index\"><i>i</i></sub>, <i>r</i><sub class=\"lower-index\"><i>i</i></sub>]</span> (both borders are included in the segment).</p><p>Help the bear cope with the problem.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains integer <span class=\"tex-span\"><i>n</i></span> <span class=\"tex-span\">(1 ≤ <i>n</i> ≤ 10<sup class=\"upper-index\">6</sup>)</span>. The second line contains <span class=\"tex-span\"><i>n</i></span> integers <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">1</sub>, <i>x</i><sub class=\"lower-index\">2</sub>, ..., <i>x</i><sub class=\"lower-index\"><i>n</i></sub></span> <span class=\"tex-span\">(2 ≤ <i>x</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 10<sup class=\"upper-index\">7</sup>)</span>. The numbers are not necessarily distinct.</p><p>The third line contains integer <span class=\"tex-span\"><i>m</i></span> <span class=\"tex-span\">(1 ≤ <i>m</i> ≤ 50000)</span>. Each of the following <span class=\"tex-span\"><i>m</i></span> lines contains a pair of space-separated integers, <span class=\"tex-span\"><i>l</i><sub class=\"lower-index\"><i>i</i></sub></span> and <span class=\"tex-span\"><i>r</i><sub class=\"lower-index\"><i>i</i></sub></span> <span class=\"tex-span\">(2 ≤ <i>l</i><sub class=\"lower-index\"><i>i</i></sub> ≤ <i>r</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 2·10<sup class=\"upper-index\">9</sup>)</span> — the numbers that characterize the current query.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print <span class=\"tex-span\"><i>m</i></span> integers — the answers to the queries on the order the queries appear in the input.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>6<br />5 5 7 10 14 15<br />3<br />2 11<br />3 12<br />4 4<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>9<br />7<br />0<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>7<br />2 3 5 7 11 4 8<br />2<br />8 10<br />2 123<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>0<br />7<br /></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>Consider the first sample. Overall, the first sample has 3 queries.</p><ol> <li> The first query <span class=\"tex-span\"><i>l</i> = 2</span>, <span class=\"tex-span\"><i>r</i> = 11</span> comes. You need to count <span class=\"tex-span\"><i>f</i>(2) + <i>f</i>(3) + <i>f</i>(5) + <i>f</i>(7) + <i>f</i>(11) = 2 + 1 + 4 + 2 + 0 = 9</span>. </li><li> The second query comes <span class=\"tex-span\"><i>l</i> = 3</span>, <span class=\"tex-span\"><i>r</i> = 12</span>. You need to count <span class=\"tex-span\"><i>f</i>(3) + <i>f</i>(5) + <i>f</i>(7) + <i>f</i>(11) = 1 + 4 + 2 + 0 = 7</span>. </li><li> The third query comes <span class=\"tex-span\"><i>l</i> = 4</span>, <span class=\"tex-span\"><i>r</i> = 4</span>. As this interval has no prime numbers, then the sum equals 0. </li></ol></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=C]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== statementText) {\r\n $problem.find(\".diff-notifier\").show();\r\n\r\n $problem.find(\".diff-notifier-close\").click(function() {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n $problem.find(\".diff-notifier\").hide();\r\n });\r\n\r\n $problem.find(\"a.view-changes\").click(function() {\r\n $.post(\"/data/diff\", {action: \"getDiff\", a: previousStatementText, b: statementText}, function (result) {\r\n if (result[\"success\"] === \"true\") {\r\n Codeforces.facebox(\".diff-popup\", \"//codeforces.org/s/73366\");\r\n $(\"#facebox .diff-popup\").html(result[\"diff\"]);\r\n }\r\n }, \"json\");\r\n });\r\n }\r\n } else {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n }\r\n });\r\n });\r\n </script>\r\n\r\n\r\n<script type=\"text/javascript\">\r\n $(document).ready(function () {\r\n window.changedTests = new Set();\r\n\r\n function endsWith(string, suffix) {\r\n return string.indexOf(suffix, string.length - suffix.length) !== -1;\r\n }\r\n\r\n const inputFileDiv = $(\"div.input-file\");\r\n const inputFile = inputFileDiv.text();\r\n const outputFileDiv = $(\"div.output-file\");\r\n const outputFile = outputFileDiv.text();\r\n\r\n\r\n if (!endsWith(inputFile, \"standard input\")\r\n && !endsWith(inputFile, \"standard input\")) {\r\n inputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n if (!endsWith(outputFile, \"standard output\")\r\n && !endsWith(outputFile, \"standard output\")) {\r\n outputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n const titleDiv = $(\"div.header div.title\");\r\n\r\n\r\n\r\n String.prototype.replaceAll = function (search, replace) {\r\n return this.split(search).join(replace);\r\n };\r\n\r\n $(\".sample-test .title\").each(function () {\r\n const preId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n const cpyId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n\r\n $(this).parent().find(\"pre\").attr(\"id\", preId);\r\n const $copy = $(\"<div title='Copy' data-clipboard-target='#\" + preId + \"' id='\" + cpyId + \"' class='input-output-copier'>Copy</div>\");\r\n $(this).append($copy);\r\n\r\n const clipboard = new Clipboard('#' + cpyId, {\r\n text: function (trigger) {\r\n const pre = document.querySelector('#' + preId);\r\n const lines = pre.querySelectorAll(\".test-example-line\");\r\n return Codeforces.filterClipboardText(pre.innerText, lines.length);\r\n }\r\n });\r\n\r\n const isInput = $(this).parent().hasClass(\"input\");\r\n\r\n clipboard.on('success', function (e) {\r\n if (isInput) {\r\n Codeforces.showMessage(\"The example input has been copied into the clipboard\");\r\n } else {\r\n Codeforces.showMessage(\"The example output has been copied into the clipboard\");\r\n }\r\n e.clearSelection();\r\n });\r\n });\r\n\r\n $(\".test-form-item input\").change(function () {\r\n addPendingSubmissionMessage($($(this).closest(\"form\")), \"You changed the answer, do not forget to submit it if you want to save the changes\");\r\n const index = $(this).closest(\".problemindexholder\").attr(\"problemindex\");\r\n let test = \"\";\r\n $(this).closest(\"form input\").each(function () {\r\n const test_ = $(this).attr(\"name\");\r\n if (test_ && test_.substring(0, 4) === \"test\") {\r\n test = test_;\r\n }\r\n });\r\n if (index.length > 0 && test.length > 0) {\r\n const indexTest = index + \"::\" + test;\r\n window.changedTests.add(indexTest);\r\n }\r\n });\r\n\r\n $(window).on('beforeunload', function () {\r\n if (window.changedTests.size > 0) {\r\n return 'Dialog text here';\r\n }\r\n });\r\n\r\n autosize($('.test-explanation textarea'));\r\n\r\n $(\".test-example-line\").hover(function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n let top = 1E20;\r\n let left = 1E20;\r\n let problem = $(this).closest(\".problemindexholder\");\r\n $(this).closest(\".input\").find(\".\" + clazz).css(\"background-color\", \"#FFFDE7\").each(function() {\r\n top = Math.min(top, $(this).offset().top);\r\n left = Math.min(left, $(this).offset().left);\r\n });\r\n let testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n if (testCaseMarker.length === 0) {\r\n const html = \"<div class=\\\"testCaseMarker testCaseMarker_\" + end + \" notice\\\"></div>\";\r\n problem.append($(html));\r\n testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n }\r\n if (testCaseMarker) {\r\n testCaseMarker.show()\r\n .offset({top, left: left - 20})\r\n .text(end);\r\n }\r\n }\r\n }\r\n });\r\n }, function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n $(\".\" + clazz).css(\"background-color\", \"\");\r\n $(this).closest(\".problemindexholder\").find(\".testCaseMarker_\" + end).hide();\r\n }\r\n }\r\n });\r\n });\r\n\r\n });\r\n</script>\r\n\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 05:38:13</span> (j3).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/73366/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/73366/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/73366/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/73366/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-73366.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'8122c444c86215f2',t:'MTY5NjY0NjI5My4zNjUwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"},"long_tags":{"kind":"string","value":"[\"Binary search\", \"Brute force\", \"Heaps, binary search trees, segment trees, hash tables, etc\", \"Dynamic programming\", \"Implementation problems, programming technics, simulation\", \"Mathematics including integration, differential equations, etc\", \"Number theory: Euler function, GCD, divisibility, etc\"]"},"short_tags":{"kind":"string","value":"[\"binary search\", \"brute force\", \"data structures\", \"dp\", \"implementation\", \"math\", \"number theory\", \"*1700\"]"},"tutorial_link":{"kind":"string","value":"https://codeforces.com/blog/entry/10514"},"tutorial_page":{"kind":"string","value":"\r\n\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"b0edd04b6e615eea61c4a67daabca579\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"h1\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Codeforces Round #226 (Div. 2) — Editorial - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n \n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Codeforces Round #226 (Div. 2) — Editorial - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/81027/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/81027/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/81027/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/81027/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/81027/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/81027/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/81027/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/81027/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/81027/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/81027/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/81027/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/81027/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/81027/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/81027/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/573cedc6b04c15481941f418269f4057/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='b0edd04b6e615eea61c4a67daabca579'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/81027/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fblog%2Fentry%2F10514\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='b0edd04b6e615eea61c4a67daabca579'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Pay attention\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n <div style=\"text-align:center;border-bottom: 1px solid rgb(185, 185, 185);margin:0 -0.5em 0.5em -0.5em;padding: 0 1em 0.5em 1em;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 1, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:51:56</span><br/><a href=\"/contestRegistration/1876\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n <div style=\"text-align:center;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 2, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:51:56</span><br/><a href=\"/contestRegistration/1877\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='b0edd04b6e615eea61c4a67daabca579'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n </label>\r\n </div>\r\n <div style=\"padding: 0 1em 1em 1em;text-align:right;\">\r\n <input style=\"height:1.65em;padding:0 0.75em;\" type=\"submit\" value=\"Find\"/>\r\n </div>\r\n </form>\r\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".handleBox\").autocomplete(\"/data/handles\", {\r\n delay: 200,\r\n width: 200,\r\n selectFirst: false,\r\n matchContains: true,\r\n minChars: 3\r\n });\r\n $(\".handleForm\").attr(\"autocomplete\", \"off\").submit(function () {\r\n var link = \"/profile/userHandle\".replace(\r\n \"userHandle\", $(this).find(\".handleBox\").val()\r\n );\r\n window.location = link;\r\n return false;\r\n });\r\n });\n </script>\n\r\n\r\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Recent actions\n <div class=\"top-links\">\n </div>\n </div>\n <div class=\"recent-actions\">\r\n <ul>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/121073\">Meta Hacker Cup 2023 Round 1</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/.Danet\" title=\"Expert .Danet\" class=\"rated-user user-blue\">.Danet</a> →\r\n <a href=\"/blog/entry/121172\">[TLE on pretest1]</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\" class=\"rated-user user-red\">Pyqe</a> →\r\n <a href=\"/blog/entry/121025\">Codeforces Round #902 (Div. 1, Div. 2, based on COMPFEST 15 — Final Round)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pranshu_Pandya\" title=\"Specialist Pranshu_Pandya\" class=\"rated-user user-cyan\">Pranshu_Pandya</a> →\r\n <a href=\"/blog/entry/121171\">An Interesting Tree Problem</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/sszcdjr\" title=\"Master sszcdjr\" class=\"rated-user user-orange\">sszcdjr</a> →\r\n <a href=\"/blog/entry/119859\">Codeforces Round 896 (Div. 1, Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/119880\">It's Happening! Meta Hacker Cup 2023 Schedule</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/DaviddeGea1\" title=\"Expert DaviddeGea1\" class=\"rated-user user-blue\">DaviddeGea1</a> →\r\n <a href=\"/blog/entry/70917\">Number of ways of dividing an array into 2 parts such that sum of each part is > k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bekh\" title=\"Master Bekh\" class=\"rated-user user-orange\">Bekh</a> →\r\n <a href=\"/blog/entry/74245\">Questions and doubts regarding Aliens DP trick</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a> →\r\n <a href=\"/blog/entry/8192\">Codeforces Round #190 — Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/hocky\" title=\"Candidate Master hocky\" class=\"rated-user user-violet\">hocky</a> →\r\n <a href=\"/blog/entry/95323\">FBHC wuining uw Day? Incwease uw stacc size! (ㅅ´ ˘ `)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/liouzhou_101\" title=\"International Master liouzhou_101\" class=\"rated-user user-orange\">liouzhou_101</a> →\r\n <a href=\"/blog/entry/87598\">Editorial of Codeforces Round #700</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/yeon_gist\" title=\"Newbie yeon_gist\" class=\"rated-user user-gray\">yeon_gist</a> →\r\n <a href=\"/blog/entry/121170\">plusMinusPermutation computing error</a>\r\n <img alt=\"Text created or updated\" title=\"Text created or updated\" src=\"//codeforces.org/s/81027/images/icons/x-update-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/altforminuscontribution\" title=\"Newbie altforminuscontribution\" class=\"rated-user user-gray\">altforminuscontribution</a> →\r\n <a href=\"/blog/entry/121162\">My screen get unexpectedly big, what should I do</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/atcoder_official\" title=\"Unrated, atcoder_official\" class=\"rated-user user-black\">atcoder_official</a> →\r\n <a href=\"/blog/entry/121120\">We will hold UNIQUE VISION Programming Contest 2023 Autumn(AtCoder Beginner Contest 323)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/YouStill_DontKnowMeYet\" title=\"Candidate Master YouStill_DontKnowMeYet\" class=\"rated-user user-violet\">YouStill_DontKnowMeYet</a> →\r\n <a href=\"/blog/entry/117659\">[GYM] Al-Baath Collegiate Programming Contest 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/ankancool\" title=\"Expert ankancool\" class=\"rated-user user-blue\">ankancool</a> →\r\n <a href=\"/blog/entry/121136\">Invitation to AstroByte 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/GeZhiyuan\" title=\"Grandmaster GeZhiyuan\" class=\"rated-user user-red\">GeZhiyuan</a> →\r\n <a href=\"/blog/entry/120943\">Codeforces Round 901 (Div. 1, Div. 2) Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a> →\r\n <a href=\"/blog/entry/120772\">PSA: Increase your stack size before the Meta Hacker Cup, here's how</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/dino_merlin\" title=\"Expert dino_merlin\" class=\"rated-user user-blue\">dino_merlin</a> →\r\n <a href=\"/blog/entry/121145\">Intuitive approach for CEOI Kangaroo?</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/icecuber\" title=\"Grandmaster icecuber\" class=\"rated-user user-red\">icecuber</a> →\r\n <a href=\"/blog/entry/70018\">CSES DP section editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bn00b\" title=\"Newbie Bn00b\" class=\"rated-user user-gray\">Bn00b</a> →\r\n <a href=\"/blog/entry/98820\">[FEATURE REQUEST : ATCODER] TOPICS TAGS AND SORTING BY SOLVE COUNT</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a> →\r\n <a href=\"/blog/entry/121163\">AtCoder Regular Contest 166 Announcement</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/windva\" title=\"Grandmaster windva\" class=\"rated-user user-red\">windva</a> →\r\n <a href=\"/blog/entry/120644\">Codeforces Round 899 (Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Misa-Misa\" title=\"Expert Misa-Misa\" class=\"rated-user user-blue\">Misa-Misa</a> →\r\n <a href=\"/blog/entry/121157\">Someone please help me understand this.</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/shivam565\" title=\"Specialist shivam565\" class=\"rated-user user-cyan\">shivam565</a> →\r\n <a href=\"/blog/entry/108348\">Total number of subarrays with sum atmost k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n </ul>\r\n </div>\r\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/recent-actions\">Detailed →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n</div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li><a\r\n href=\"/profile/CleRIC\">CleRIC</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/CleRIC\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/CleRIC\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/CleRIC\">Submissions</a></li>\r\n <li><a\r\n href=\"/groups/with/CleRIC\">Groups</a></li>\r\n <li><a\r\n href=\"/contests/with/CleRIC\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/CleRIC\">Problemsetting</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/CleRIC\" style=\"text-decoration:none;color:black !important;\">CleRIC's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"10569\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/10514\"> <p>Codeforces Round #226 (Div. 2) — Editorial</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/CleRIC\" title=\"Candidate Master CleRIC\" class=\"rated-user user-violet\">CleRIC</a>,\r\n <span class=\"format-humantime\" title=\"Jan/23/2014 19:33\">10 years ago</span>,\r\n translation,\r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p><a href=\"/contest/385/problem/A\" title=\"Codeforces Round 226 (Div. 2)\">385A - Bear and Raspberry</a></p><p>In this task required to understand that the answer max(<span class=\"tex-span\"><i>a</i>[<i>i</i>] - <i>a</i>[<i>i</i> - 1] - <i>c</i></span>),<span class=\"tex-span\"><i>i</i></span> = <span class=\"tex-span\">2..<i>n</i></span> and don't forget that the answer not negative as Bear can not borrow in the debt barrel of honey.</p><p><a href=\"/contest/385/problem/B\" title=\"Codeforces Round 226 (Div. 2)\">385B - Bear and Strings</a></p><p>In this problem you could write a better solution than the naive. To do this, you can iterate through the first cycle of the left index <span class=\"tex-span\"><i>l</i></span> considered substring and the second cycle of the right index <span class=\"tex-span\"><i>r</i></span> considered substring <span class=\"tex-span\">(<i>l</i> ≤ <i>r</i>)</span>. If any position has been substring "bear", means all the strings <span class=\"tex-span\"><i>x</i>(<i>l</i>, <i>j</i>)</span> <span class=\"tex-span\">(<i>i</i> ≤ <i>j</i>)</span>, also contain "bear" as a substring. So we can add to the answer <span class=\"tex-span\">|<i>s</i>| - <i>j</i> + 1</span> and exit from the second cycle. Also needed to understand, that if the string <span class=\"tex-span\"><i>x</i>(<i>l</i>, <i>j</i>)</span> was not a substring "bear", then in row <span class=\"tex-span\"><i>x</i>(<i>l</i>, <i>j</i> + 1)</span> substring "bear" could appear only in the last four characters.</p><p><a href=\"/contest/385/problem/C\" title=\"Codeforces Round 226 (Div. 2)\">385C - Bear and Prime Numbers</a></p><p>In order to solve given problem, contestant should solve several subproblems :</p><p>1) First one is to compute amount of entries of each natural number between <span class=\"tex-span\">2</span> and <span class=\"tex-span\">10<sup class=\"upper-index\">7</sup></span> in given list. This subproblem can be solved by creating array <span class=\"tex-span\"><i>count</i></span> of <span class=\"tex-span\">10<sup class=\"upper-index\">7</sup></span> elements and increasing corresponding element when scanning input.</p><p>2) Second one is to compute <span class=\"tex-span\"><i>f</i>(<i>n</i>)</span>.</p><p>First of all, we need to find all primes less than <span class=\"tex-span\">10<sup class=\"upper-index\">7</sup></span> and then for each prime <span class=\"tex-span\"><i>n</i></span> compute <span class=\"tex-span\"><i>f</i>(<i>n</i>)</span>.</p><p>How to compute <span class=\"tex-span\"><i>f</i>(2)</span>? We should sum <span class=\"tex-span\"><i>count</i>[2]</span>,<span class=\"tex-span\"><i>count</i>[4]</span>,<span class=\"tex-span\"><i>count</i>[6]</span>,<span class=\"tex-span\"><i>count</i>[8]</span>,...</p><p>How to compute <span class=\"tex-span\"><i>f</i>(5)</span>? We should sum <span class=\"tex-span\"><i>count</i>[5]</span>,<span class=\"tex-span\"><i>count</i>[10]</span>,<span class=\"tex-span\"><i>count</i>[15]</span>,<span class=\"tex-span\"><i>count</i>[20]</span>,...</p><p>How to compute <span class=\"tex-span\"><i>f</i>(<i>n</i>)</span>? We should sum <span class=\"tex-span\"><i>count</i>[<i>n</i>]</span>,<span class=\"tex-span\"><i>count</i>[2·<i>n</i>]</span>,<span class=\"tex-span\"><i>count</i>[3·<i>n</i>]</span>,<span class=\"tex-span\"><i>count</i>[4·<i>n</i>]</span>,...</p><p>It can be seen that given algo is very similar to Sieve of Eratosthenes. (Info here <a href=\"http://e-maxx.ru/algo/eratosthenes_sieve\">http://e-maxx.ru/algo/eratosthenes_sieve</a>) So we can use this algo if we change it a little bit. Also, we will store results of calculation in array, e.g. <span class=\"tex-span\"><i>pre</i></span>. Namely, <span class=\"tex-span\"><i>pre</i>[<i>n</i>]</span> = <span class=\"tex-span\"><i>f</i>(<i>n</i>)</span>.</p><p>3) Now we can calculate partial sums of <span class=\"tex-span\"><i>pre</i></span> array. It can be made in a single pass just adding <span class=\"tex-span\"><i>pre</i>[<i>i</i> - 1]</span> to <span class=\"tex-span\"><i>pre</i>[<i>i</i>]</span>.</p><p>4) If we know partial sums of array then we can calculate sum of array elements between <span class=\"tex-span\"><i>l</i></span> and <span class=\"tex-span\"><i>r</i></span> in time proportional <span class=\"tex-span\"><i>O</i>(1)</span>, just calculate <span class=\"tex-span\"><i>pre</i>[<i>r</i>] - <i>pre</i>[<i>l</i> - 1]</span>.</p><p>5) Now we can read queries and immediately response to them. You shouldn't forget that right boundaries of intervals can be greater than <span class=\"tex-span\">10<sup class=\"upper-index\">7</sup></span>, so you can always decrease it to <span class=\"tex-span\">10<sup class=\"upper-index\">7</sup></span>, because all numbers in given list are less than <span class=\"tex-span\">10<sup class=\"upper-index\">7</sup></span>.</p><p><a href=\"/contest/385/problem/D\" title=\"Codeforces Round 226 (Div. 2)\">385D - Bear and Floodlight</a></p><p>In this task, it is crucial to understand that whether there is lighted part of road with length <span class=\"tex-span\"><i>dist</i></span> then next part should be lit in a such way that leftmost lighted point is touching with <span class=\"tex-span\"><i>dist</i></span>.</p><p>Let's suppose that road is lit from <span class=\"tex-span\"><i>l</i></span> to <span class=\"tex-span\"><i>d</i></span>. How we can find rightmost point on X axis that would be lit by next floodlight?</p><p>We can just use concepts of vector and rotation matrix.</p><p>Let's find vector <span class=\"tex-span\">(<i>dx</i>, <i>dy</i>)</span> from floodlight to point on X axis <span class=\"tex-span\">(<i>d</i>, 0)</span>. <span class=\"tex-span\">(<i>dx</i>, <i>dy</i>)</span> = <span class=\"tex-span\">(<i>d</i> - <i>x</i>, 0 - <i>y</i>)</span>.</p><p>Next point to rotate vector by <span class=\"tex-span\"><i>angle</i></span> degrees. We can use rotation matrix for this purpose.</p><p><span class=\"tex-span\">(<i>dx</i>, <i>dy</i>)</span> = <span class=\"tex-span\">(<i>dx</i>·<i>cos</i>(<i>angle</i>) - <i>dy</i>·<i>sin</i>(<i>angle</i>), <i>dx</i>·<i>sin</i>(<i>angle</i>) + <i>dy</i>·<i>cos</i>(<i>angle</i>))</span></p><p>Next, we should make second component <span class=\"tex-span\"><i>dy</i></span> of <span class=\"tex-span\">(<i>dx</i>, <i>dy</i>)</span> equal to <span class=\"tex-span\">1</span> by multiplying on coefficient <span class=\"tex-span\"><i>k</i></span>.</p><p>Now we can determine rightmost lighted point of X axis. It is <span class=\"tex-span\"><i>x</i> - <i>y</i>·<i>dx</i></span>.</p><p>You shouldn't forget that there is possibility for rightmost point to be infinitely far point.</p><p>From now on we can forget about geometry in this task.</p><p>Let's find fast way to determine optimal order of floodlights.</p><p>To achieve this goal, we can use dynamic programming approach. Namely, let's calculate answer for subsets of floodlights. Each subset would be represented as integer where <span class=\"tex-span\"><i>k</i></span> bit would be <span class=\"tex-span\">1</span> if <span class=\"tex-span\"><i>k</i></span> floodlight is presented in subset and <span class=\"tex-span\">0</span> if it is not, i.e. so named binary mask.</p><p>For example, <span class=\"tex-span\"><i>dp</i>[6]</span> — (<span class=\"tex-span\">6</span> — <span class=\"tex-span\">110<sub class=\"lower-index\">2</sub></span>) is optimal answer for subset from <span class=\"tex-span\">2</span> and <span class=\"tex-span\">3</span> floodlight.</p><p>Now, let's look through subsets <span class=\"tex-span\"><i>i</i></span> in <span class=\"tex-span\"><i>dp</i>[<i>i</i>]</span>. In subset <span class=\"tex-span\"><i>i</i></span> let's go through absent floodlights <span class=\"tex-span\"><i>j</i></span> and update result for subset where <span class=\"tex-span\"><i>j</i></span> floodlight is present, i.e. dp[ <span class=\"tex-span\"><i>i</i></span> or <span class=\"tex-span\">2<sup class=\"upper-index\"><i>j</i></sup></span> ] = max(dp[ <span class=\"tex-span\"><i>i</i></span> or <span class=\"tex-span\">2<sup class=\"upper-index\"><i>j</i></sup></span>], dp[ <span class=\"tex-span\"><i>i</i></span> ] + calc_rightmost_lighted_point() ). As we can calculate rightmost lighted point, so updating of answer shouldn't be a problem.</p><p><a href=\"/contest/385/problem/E\" title=\"Codeforces Round 226 (Div. 2)\">385E - Bear in the Field</a></p><p>In this task there are several problems that should be concerned:</p><p>1) Simple modeling of bear movement would cause TLE due to <span class=\"tex-span\"><i>t</i></span> <span class=\"tex-span\"> ≤ </span> <span class=\"tex-span\">10<sup class=\"upper-index\">18</sup></span>.</p><p>2) Task can't be solved by separating <span class=\"tex-span\"><i>x</i></span> and <span class=\"tex-span\"><i>y</i></span> axes because <span class=\"tex-span\"><i>x</i></span> and <span class=\"tex-span\"><i>y</i></span> depends on each other.</p><p>3) Also, we can't use standart method of cycle finding via modeling for a short time and checking on collisions because coordinates limitations are very large.</p><p>Let's say we have matrix <span class=\"tex-span\">(<i>x</i><sub class=\"lower-index\"><i>i</i></sub>, <i>y</i><sub class=\"lower-index\"><i>i</i></sub>, <i>dx</i><sub class=\"lower-index\"><i>i</i></sub>, <i>dy</i><sub class=\"lower-index\"><i>i</i></sub>, <i>t</i><sub class=\"lower-index\"><i>i</i></sub>, 1)</span>.</p><p>If we multiply previous matrix by following matrix long long base[6][6] = {</p><p>{2,1,1,1,0,0},</p><p>{1,2,1,1,0,0},</p><p>{1,0,1,0,0,0},</p><p>{0,1,0,1,0,0},</p><p>{0,0,1,1,1,0},</p><p>{0,0,2,2,1,1} };</p><p>we will have get parameters on next step.</p><p>Where did the matrix? Let us write out how to change parameters with each step and see the similarity matrix.</p><p><span class=\"tex-span\"><i>x</i></span> = <span class=\"tex-span\">2·<i>x</i></span> + <span class=\"tex-span\">1·<i>y</i></span> + <span class=\"tex-span\">1·<i>dx</i></span> + <span class=\"tex-span\">0·<i>dy</i></span> + <span class=\"tex-span\">0·<i>t</i></span> + <span class=\"tex-span\">0·1</span>.</p><p><span class=\"tex-span\"><i>y</i></span> = <span class=\"tex-span\">1·<i>x</i></span> + <span class=\"tex-span\">2·<i>y</i></span> + <span class=\"tex-span\">0·<i>dx</i></span> + <span class=\"tex-span\">1·<i>dy</i></span> + <span class=\"tex-span\">0·<i>t</i></span> + <span class=\"tex-span\">0·1</span>.</p><p><span class=\"tex-span\"><i>dx</i></span> = <span class=\"tex-span\">1·<i>x</i></span> + <span class=\"tex-span\">1·<i>y</i></span> + <span class=\"tex-span\">1·<i>dx</i></span> + <span class=\"tex-span\">0·<i>dy</i></span> + <span class=\"tex-span\">1·<i>t</i></span> + <span class=\"tex-span\">2·1</span>.</p><p><span class=\"tex-span\"><i>dy</i></span> = <span class=\"tex-span\">1·<i>x</i></span> + <span class=\"tex-span\">1·<i>y</i></span> + <span class=\"tex-span\">0·<i>dx</i></span> + <span class=\"tex-span\">1·<i>dy</i></span> + <span class=\"tex-span\">1·<i>t</i></span> + <span class=\"tex-span\">2·1</span>.</p><p><span class=\"tex-span\"><i>t</i></span> = <span class=\"tex-span\">0·<i>x</i></span> + <span class=\"tex-span\">0·<i>y</i></span> + <span class=\"tex-span\">0·<i>dx</i></span> + <span class=\"tex-span\">0·<i>dy</i></span> + <span class=\"tex-span\">1·<i>t</i></span> + <span class=\"tex-span\">1·1</span>.</p><p><span class=\"tex-span\">1</span> = <span class=\"tex-span\">0·<i>x</i></span> + <span class=\"tex-span\">0·<i>y</i></span> + <span class=\"tex-span\">0·<i>dx</i></span> + <span class=\"tex-span\">0·<i>dy</i></span> + <span class=\"tex-span\">0·<i>t</i></span> + <span class=\"tex-span\">1·1</span>.</p><p>So if we calculate <span class=\"tex-span\"><i>t</i> - 1</span> power of <span class=\"tex-span\"><i>base</i></span> and then multiply <span class=\"tex-span\">(<i>sx</i>, <i>sy</i>, <i>dx</i>, <i>dy</i>, <i>t</i>, 1)</span> by it we will calculate parameters at moment <span class=\"tex-span\"><i>t</i></span>.</p><p>Power of matrix can be calculated via binary power modulo algo due to associativity of matrix multiplication. More info at <a href=\"http://e-maxx.ru/algo/binary_pow\">http://e-maxx.ru/algo/binary_pow</a></p><p>Using trivial matrix multiplication algo we will solve this task in time proportional <span class=\"tex-span\">6<sup class=\"upper-index\">3</sup>·<i>log</i>(<i>t</i>)</span>.</p></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/385\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 226 (Div. 2)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-2930-10569\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"2930\",\n blogEntryId: \"10514\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-10569\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+85</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-10569\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/CleRIC\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/CleRIC\">\n CleRIC\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Jan/23/2014 19:33\">10 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/10514#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/10514#comments\">\n 30\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"10585\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (25)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158988\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/OpalDshawn\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/40047/avatar/c26edf07c13c133a.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/OpalDshawn\" title=\"Master OpalDshawn\" class=\"rated-user user-orange\">OpalDshawn</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2014 22:59\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158988\" href=\"?#comment-158988\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"158988\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"158988\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"40047\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158988\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Great Editorial!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158988 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158988 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158988\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159026\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Xellos\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/69675/avatar/8526bcfc8e687b43.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/Xellos\" title=\"International Grandmaster Xellos\" class=\"rated-user user-red\">Xellos</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/25/2014 02:06\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159026\" href=\"?#comment-159026\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"159026\" revisionCount=\"7\" revision=\"7\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">7</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"159026\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"28\"\r\n data-commentUserId=\"69675\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+28</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159026\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I solved E (theoretically, I don't really want to implement it) by solving the system of equations:</p> <center><span class=\"tex-span\"><i>x</i>(<i>t</i>) = [<i>x</i>(<i>t</i> - 1) + <i>v</i><sub class=\"lower-index\"><i>x</i></sub>(<i>t</i>) - 1]%<i>N</i> + 1</span></center> <center><span class=\"tex-span\"><i>y</i>(<i>t</i>) = [<i>y</i>(<i>t</i> - 1) + <i>v</i><sub class=\"lower-index\"><i>y</i></sub>(<i>t</i>) - 1]%<i>N</i> + 1</span></center> <center><span class=\"tex-span\"><i>v</i><sub class=\"lower-index\"><i>x</i></sub>(<i>t</i>) = <i>v</i><sub class=\"lower-index\"><i>x</i></sub>(<i>t</i> - 1) + <i>t</i> - 1 + <i>x</i>(<i>t</i> - 1) + <i>y</i>(<i>t</i> - 1)</span></center> <center><span class=\"tex-span\"><i>v</i><sub class=\"lower-index\"><i>y</i></sub>(<i>t</i>) = <i>v</i><sub class=\"lower-index\"><i>y</i></sub>(<i>t</i> - 1) + <i>t</i> - 1 + <i>x</i>(<i>t</i> - 1) + <i>y</i>(<i>t</i> - 1)</span></center><p>for $t > 0$, where the values of <span class=\"tex-span\">(<i>x</i>, <i>y</i>, <i>v</i><sub class=\"lower-index\"><i>x</i></sub>, <i>v</i><sub class=\"lower-index\"><i>y</i></sub>)(0)</span> are given as input parameters, and the time is 0-based.</p><p>Firstly, we want to get rid of the modulo function. We can't just compute all variables modulo <span class=\"tex-span\"><i>N</i></span>, because there's the -1, so we'll shift the coordinates to <span class=\"tex-span\">(<i>x</i>', <i>y</i>')(<i>t</i>)</span>, where <span class=\"tex-span\"><i>x</i>' = <i>x</i> - 1</span>, <span class=\"tex-span\"><i>y</i>' = <i>y</i> - 1</span>. Now the equations become</p> <center><span class=\"tex-span\"><i>x</i>'(<i>t</i>) = <i>x</i>'(<i>t</i> - 1) + <i>v</i><sub class=\"lower-index\"><i>x</i></sub>(<i>t</i>)</span></center> <center><span class=\"tex-span\"><i>y</i>'(<i>t</i>) = <i>y</i>'(<i>t</i> - 1) + <i>v</i><sub class=\"lower-index\"><i>y</i></sub>(<i>t</i>)</span></center> <center><span class=\"tex-span\"><i>v</i><sub class=\"lower-index\"><i>x</i></sub>(<i>t</i>) = <i>v</i><sub class=\"lower-index\"><i>x</i></sub>(<i>t</i> - 1) + <i>t</i> + 1 + <i>x</i>'(<i>t</i> - 1) + <i>y</i>'(<i>t</i> - 1)</span></center> <center><span class=\"tex-span\"><i>v</i><sub class=\"lower-index\"><i>y</i></sub>(<i>t</i>) = <i>v</i><sub class=\"lower-index\"><i>y</i></sub>(<i>t</i> - 1) + <i>t</i> + 1 + <i>x</i>'(<i>t</i> - 1) + <i>y</i>'(<i>t</i> - 1)</span></center><p>where all variables are computed modulo $N$ (we'll omit that from now on). We can compute <span class=\"tex-span\">(<i>x</i>, <i>y</i>, <i>v</i><sub class=\"lower-index\"><i>x</i></sub>, <i>v</i><sub class=\"lower-index\"><i>y</i></sub>)(1)</span> from this, and further substitute for <span class=\"tex-span\"><i>v</i><sub class=\"lower-index\"><i>x</i></sub>, <i>v</i><sub class=\"lower-index\"><i>y</i></sub></span>, which gives for <span class=\"tex-span\"><i>t</i> > 1</span></p> <center><span class=\"tex-span\"><i>x</i>'(<i>t</i>) - <i>x</i>'(<i>t</i> - 1) = <i>x</i>'(<i>t</i> - 1) - <i>x</i>'(<i>t</i> - 2) + <i>t</i> + 1 + <i>x</i>'(<i>t</i> - 1) + <i>y</i>'(<i>t</i> - 1)</span></center> <center><span class=\"tex-span\"><i>y</i>'(<i>t</i>) - <i>y</i>'(<i>t</i> - 1) = <i>y</i>'(<i>t</i> - 1) - <i>y</i>'(<i>t</i> - 2) + <i>t</i> + 1 + <i>x</i>'(<i>t</i> - 1) + <i>y</i>'(<i>t</i> - 1)</span></center><p>Let's now define</p> <center><span class=\"tex-span\"><i>s</i>(<i>t</i>) = <i>x</i>'(<i>t</i>) + <i>y</i>'(<i>t</i>)</span></center> <center><span class=\"tex-span\"><i>d</i>(<i>t</i>) = <i>x</i>'(<i>t</i>) - <i>y</i>'(<i>t</i>)</span></center><p>using which we can rewrite the sum and difference of the equations above to</p> <center><span class=\"tex-span\"><i>d</i>(<i>t</i>) - <i>d</i>(<i>t</i> - 1) = <i>d</i>(<i>t</i> - 1) - <i>d</i>(<i>t</i> - 2)</span></center> <center><span class=\"tex-span\"><i>s</i>(<i>t</i>) - <i>s</i>(<i>t</i> - 1) = <i>s</i>(<i>t</i> - 1) - <i>s</i>(<i>t</i> - 2) + 2(<i>t</i> + 1) + 2<i>s</i>(<i>t</i> - 1)</span></center><p>Once again, we define $q(t)=s(t)+t+2$ (actually, it's <span class=\"tex-span\"><i>s</i>(<i>t</i>) + <i>t</i> + <i>c</i></span>, and we compute the constant <span class=\"tex-span\"><i>c</i></span> by substituting and trying to get the constant term to 0), and rewrite our equations to</p> <center><span class=\"tex-span\"><i>d</i>(<i>t</i>) = 2<i>d</i>(<i>t</i> - 1) - <i>d</i>(<i>t</i> - 2)</span></center> <center><span class=\"tex-span\"><i>q</i>(<i>t</i>) = 4<i>q</i>(<i>t</i> - 1) - <i>q</i>(<i>t</i> - 2)</span></center><p>which can be solved explicitly (I'm lazy, so I'm just using Wolfram Alpha, read more about linear recurrent equations on Wikipedia or something):</p> <center><img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/5ec2a1c8cb9dd5c6d22e9c89f85ea721c45a9659.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></center> <center><span class=\"tex-span\"><i>d</i>(<i>t</i>) = <i>C</i> * <i>t</i> + <i>D</i></span></center><p>where the parameters $A..D$ are given by the values for <span class=\"tex-span\"><i>t</i> ≤ 1</span>.</p><p>This is more of a theoretical solution (since as long as we get the recurrences for <span class=\"tex-span\"><i>d</i>(<i>t</i>)</span> and <span class=\"tex-span\"><i>q</i>(<i>t</i>)</span>, it's best to use matrix multiplication), but I just wanted to do it this way :D</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159026 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159026 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159026\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159027\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/bilalyasar\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/88216/avatar/25c063de47c0f66a.jpg'/> </a>\n <div><a href=\"/profile/bilalyasar\" title=\"Expert bilalyasar\" class=\"rated-user user-blue\">bilalyasar</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/25/2014 03:59\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159027\" href=\"?#comment-159027\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"159027\" revisionCount=\"23\" revision=\"23\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">23</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"159027\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"88216\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159027\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>i think the matrix should be that: {2,1,1,1,0,0},</p><p>{1,2,1,1,0,0},</p><p>{1,0,1,0,0,0},</p><p>{0,1,0,1,0,0},</p><p>{0,0,1,1,1,0},</p><p>{0,0,0,0,1,1} };</p><p>i tried and solved it. with this matrix.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159027 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159027 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159027\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159144\" commentParentId=\"159027\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Amir.bh\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/29435/avatar/84331c66da301d6d.jpg'/> </a>\n <div><a href=\"/profile/Amir.bh\" title=\"Candidate Master Amir.bh\" class=\"rated-user user-violet\">Amir.bh</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/26/2014 15:32\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159144\" href=\"?#comment-159144\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159027\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159144\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"29435\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159144\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Rev. 23????! How could this happen?! :D</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159144 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159144 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159144\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159162\" commentParentId=\"159144\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Xellos\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/69675/avatar/8526bcfc8e687b43.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/Xellos\" title=\"International Grandmaster Xellos\" class=\"rated-user user-red\">Xellos</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/26/2014 17:13\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159162\" href=\"?#comment-159162\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159144\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159162\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"69675\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159162\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Maybe for the same reason as rev.7 of my comment above — I edit my comment, click "Save", nothing happens; I wait until my internet connection is stronger, click again, and nothing happens again, etc., until I lose patience and reload the page. And look what happened: the revisions were counted, but my comment wasn't edited. Some bug of CF, maybe.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159162 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159162 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159162\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159054\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/llaki\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/24382/avatar/6683eebf7eea08ec.jpg'/> </a>\n <div><a href=\"/profile/llaki\" title=\"Expert llaki\" class=\"rated-user user-blue\">llaki</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/25/2014 15:18\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159054\" href=\"?#comment-159054\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159054\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"24382\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159054\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Nice editorial. Anyways, I had a sense that explanation of problem E does not give you an idea of how you can come up with that solution. Let me clarify that: The state can be described by following variables: x — where is the bear currently (x-coordinate); y — where is the bear currently (y-coordinate); dx — the current speed towards X axis; dy — the current speed towards Y axis; t — time passed after the start;</p><p>This information is enough to describe a state. Now let's see how the state changes: (dx)' = dx + (x+y+t), (dy)' = dy+(x+y+t), (x)' = x + (dx)' = 2x+y+dx+t, (y)'=x+2y+dy+t, (t)'= t+1.</p><p>As we see, the new state is similar to linear combination of previous state components, except for t=t+1 (1 is not in a state). It is very similar to matrix multiplication, except for we don't have 1. So we can make a matrix this way: Let's say the state is (1x6) matrix : (x, y, dx, dy, t, 1) and the matrix (M) is 100001 021110 012110 010100 001010 011111 It's easy to see why the new state is the old state matrix multiplied by M. The rest is easy, our final state is going to be the initial state matrix multiplied by the T-th power of M. Of course we're gonna use the fast exponentiation. (The naive multiplication is fine here, because the sizes are too small)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159054 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159054 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159054\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159061\" commentParentId=\"159054\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/KKpoker\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/120167/avatar/297c9d6f6c6672be.jpg'/> </a>\n <div><a href=\"/profile/KKpoker\" title=\"Specialist KKpoker\" class=\"rated-user user-cyan\">KKpoker</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/25/2014 16:34\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159061\" href=\"?#comment-159061\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159054\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"159061\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"159061\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"4\"\r\n data-commentUserId=\"120167\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+4</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159061\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>thx a lot ~ during the exam i think the raspberry will be eaten all , then the number will change from x+y-->1 a silly misunderstanding T_T</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159061 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159061 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159061\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"372356\" commentParentId=\"159054\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/nguyenit67\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/509284/avatar/98668c3aa6c04ca6.jpg'/> </a>\n <div><a href=\"/profile/nguyenit67\" title=\"Pupil nguyenit67\" class=\"rated-user user-green\">nguyenit67</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/11/2017 14:02\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-372356\" href=\"?#comment-372356\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159054\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"372356\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"509284\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-372356\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I'm sorry :) but I don't see why (x)'= x+(dx)'? Could u explain that to me?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-372356 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-372356 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-372356\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"372645\" commentParentId=\"372356\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/nguyenit67\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/509284/avatar/98668c3aa6c04ca6.jpg'/> </a>\n <div><a href=\"/profile/nguyenit67\" title=\"Pupil nguyenit67\" class=\"rated-user user-green\">nguyenit67</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/12/2017 08:25\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-372645\" href=\"?#comment-372645\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-372356\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"372645\" revisionCount=\"4\" revision=\"4\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">4</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"372645\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"509284\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-372645\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Ah</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-372645 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-372645 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-372645\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"372646\" commentParentId=\"159054\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/nguyenit67\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/509284/avatar/98668c3aa6c04ca6.jpg'/> </a>\n <div><a href=\"/profile/nguyenit67\" title=\"Pupil nguyenit67\" class=\"rated-user user-green\">nguyenit67</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/12/2017 08:26\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-372646\" href=\"?#comment-372646\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159054\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"372646\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"509284\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-372646\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Ah now I see it. Thank you for your explanation :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-372646 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-372646 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-372646\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159079\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/MoustafaMaher\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/47658/avatar/48ad52ec2bf89c75.jpg'/> </a>\n <div><a href=\"/profile/MoustafaMaher\" title=\"Candidate Master MoustafaMaher\" class=\"rated-user user-violet\">MoustafaMaher</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/25/2014 19:18\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159079\" href=\"?#comment-159079\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159079\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"47658\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159079\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Problem D !?! </p><p>how u can calculate calc_rightmost_lighted_point() in ur Dp without keeping the last right_most_point u can get till before this state </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159079 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159079 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159079\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159093\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Lord_F\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/41018/avatar/1e2b817ca83c107e.jpg'/> </a>\n <div><a href=\"/profile/Lord_F\" title=\"Candidate Master Lord_F\" class=\"rated-user user-violet\">Lord_F</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/25/2014 21:37\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159093\" href=\"?#comment-159093\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"159093\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"159093\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"41018\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159093\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>By the way, in problem D you can use law of sines to find the distance that is lighted with some floodlight.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159093 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159093 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159093\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159105\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/-emli-\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/29285/avatar/9fa3a36fa8f9d060.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/-emli-\" title=\"Pupil -emli-\" class=\"rated-user user-green\">-emli-</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/25/2014 23:59\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159105\" href=\"?#comment-159105\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159105\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"29285\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159105\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In problem C , i can't understand why we add pre[i-1] to pre[i]?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159105 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159105 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159105\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159109\" commentParentId=\"159105\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/piotreekw\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/piotreekw\" title=\"Specialist piotreekw\" class=\"rated-user user-cyan\">piotreekw</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/26/2014 00:51\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159109\" href=\"?#comment-159109\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159105\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159109\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"151924\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159109\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>If you iterate i from 2 to n-1 adding pre[i-1] to pre[i], every new pre[i] will contain sum of all pre from 1 to i</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159109 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159109 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159109\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159126\" commentParentId=\"159109\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/-emli-\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/29285/avatar/9fa3a36fa8f9d060.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/-emli-\" title=\"Pupil -emli-\" class=\"rated-user user-green\">-emli-</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/26/2014 09:24\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159126\" href=\"?#comment-159126\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159109\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159126\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"29285\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159126\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thank you! one more question how to prove that pre[r]-pre[l-1] is answer of query?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159126 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159126 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159126\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159129\" commentParentId=\"159126\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ReekinAcer\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/ReekinAcer\" title=\"Expert ReekinAcer\" class=\"rated-user user-blue\">ReekinAcer</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/26/2014 12:01\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159129\" href=\"?#comment-159129\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159126\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159129\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"106426\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159129\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I think it is clearer if we denote Cnt[i] = f(i) and Sum[i] = Cnt[1] + Cnt[2] + ... + Cnt[i]. Now, the answer for a query on [l, r] is Sum[r]-Sum[l-1].</p><p>Sum[r]-Sum[l-1] = (Cnt[1] + Cnt[2] + ... + Cnt[r])-(Cnt[1] + Cnt[2] + ... + Cnt[l-1]) = [(Cnt[1] + ... + Cnt[l-1]) + (Cnt[l] + Cnt[l + 1] + ... + Cnt[r])] — (Cnt[1] + ... + Cnt[l-1]) = Cnt[l] + Cnt[l + 1] + ... + Cnt[r].</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159129 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159129 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159129\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"211346\" commentParentId=\"159105\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/G_Hani\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/119692/avatar/ea9b44051a710c1b.jpg'/> </a>\n <div><a href=\"/profile/G_Hani\" title=\"Specialist G_Hani\" class=\"rated-user user-cyan\">G_Hani</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/06/2015 00:49\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-211346\" href=\"?#comment-211346\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159105\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"211346\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"119692\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-211346\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p><a class=\"rated-user user-green\" href=\"/profile/-emli-\" title=\"Pupil -emli-\">-emli-</a> <a class=\"rated-user user-blue\" href=\"/profile/ReekinAcer\" title=\"Expert ReekinAcer\">ReekinAcer</a> can u help me please. here my code for C and get WA at tc 4 !! <a href=\"/contest/385/submission/9731769\" title=\"Submission 9731769 by G_Hani\">9731769</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-211346 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-211346 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-211346\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159138\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/shubh09\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/shubh09\" title=\"Expert shubh09\" class=\"rated-user user-blue\">shubh09</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/26/2014 13:36\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159138\" href=\"?#comment-159138\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159138\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"72364\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159138\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Nice editorial! But I suppose that a link to a solution implementing the idea outlined in the editorial for every question would help us understand them even better!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159138 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159138 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159138\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159141\" commentParentId=\"159138\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Lord_F\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/41018/avatar/1e2b817ca83c107e.jpg'/> </a>\n <div><a href=\"/profile/Lord_F\" title=\"Candidate Master Lord_F\" class=\"rated-user user-violet\">Lord_F</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/26/2014 14:13\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159141\" href=\"?#comment-159141\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159138\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"159141\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"159141\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"41018\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159141\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Well, you can use "Status filter"</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159141 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159141 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159141\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159178\" commentParentId=\"159141\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/shubh09\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/shubh09\" title=\"Expert shubh09\" class=\"rated-user user-blue\">shubh09</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/26/2014 18:14\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159178\" href=\"?#comment-159178\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159141\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159178\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"72364\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159178\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Well, not all the accepted solutions use the idea mentioned in the editorials. It's a bit inconvenient browsing through all accepted solutions to find the one which does.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159178 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159178 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159178\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"330629\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/adityagupta1089\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/337877/avatar/e2156094910d501.jpg'/> </a>\n <div><a href=\"/profile/adityagupta1089\" title=\"Expert adityagupta1089\" class=\"rated-user user-blue\">adityagupta1089</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Dec/14/2016 22:58\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-330629\" href=\"?#comment-330629\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"330629\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"330629\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"337877\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-330629\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In problem C, I did made a cnt array (or say a hashmap) and did find all primes below the maximum x using Sieve of Erathosthenes, then for each prime I iterated over every number and and found f(p) and stored them in a Binary Index Tree, but that didn't help. I believe my complexity is O(n(logn)(loglogn)+m(logn+logP)+PlogP) where P(664,579~10^7) is the count of primes below maximum x so total operations are around 5e6+6e7+4e7 but it has a TLE?.<a href=\"//codeforces.com/contest/385/submission/22981801\">This</a> is my submission.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-330629 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-330629 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-330629\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"587392\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/reet_bhaati\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1176149/avatar/7f68facc9bda856e.jpg'/> </a>\n <div><a href=\"/profile/reet_bhaati\" title=\"Specialist reet_bhaati\" class=\"rated-user user-cyan\">reet_bhaati</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/10/2020 10:46\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-587392\" href=\"?#comment-587392\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"587392\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"-8\"\r\n data-commentUserId=\"1176149\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-587392\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>can anyone help me out? I have tried 385C and it gives me a runtime error on test case 4 link to my code — <a href=\"https://ideone.com/fork/GMagWh\">https://ideone.com/fork/GMagWh</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-587392 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-587392 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-587392\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"642670\" commentParentId=\"587392\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/back_to_code\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1292092/avatar/b57b403a9af2ef26.jpg'/> </a>\n <div><a href=\"/profile/back_to_code\" title=\"Specialist back_to_code\" class=\"rated-user user-cyan\">back_to_code</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/15/2020 21:38\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-642670\" href=\"?#comment-642670\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-587392\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"642670\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"642670\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1292092\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-642670\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I don't know if you are still looking for this :</p><p>That might be because x or y i.e the query ranges might be going out of limits. Also it may help the others who attempt it.</p><p>Edit : Also if anyone is getting TLE even after implementing same approach use:</p> <pre><code>ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);\n</code></pre></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-642670 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-642670 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-642670\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"658423\" commentParentId=\"587392\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/apoorva222g\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1213778/avatar/2153e9cce1fd37f.jpg'/> </a>\n <div><a href=\"/profile/apoorva222g\" title=\"Expert apoorva222g\" class=\"rated-user user-blue\">apoorva222g</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/09/2020 11:58\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-658423\" href=\"?#comment-658423\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-587392\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"658423\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1213778\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-658423\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Reduce any l or r to 10^7 if it is greater than 10^7. Try this case 1 2000 1 1424767024 1629755604</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-658423 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-658423 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-658423\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"686007\" commentParentId=\"658423\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/y0g38h_kum4r\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1561883/avatar/5594dfbdb87a226d.jpg'/> </a>\n <div><a href=\"/profile/y0g38h_kum4r\" title=\"Expert y0g38h_kum4r\" class=\"rated-user user-blue\">y0g38h_kum4r</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/25/2020 02:40\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-686007\" href=\"?#comment-686007\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-658423\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"686007\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1561883\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-686007\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>OH! thanks a lot for this test case!!!!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-686007 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-686007 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-686007\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n <br/>\r\n\r\n<div id=\"editBox-10585\" style=\"width:50em;display:none;\">\r\n <div class=\"previewBody\" style=\"border: 1px solid #d4d4d4; margin-bottom: 0.5em; padding: 0.25em; display:none;\"> </div>\r\n <div style=\"width: 1px\"> </div>\r\n <div class=\"commentLocale\" style=\"position: relative; top: 0.5em;left:4px;display: none;\">\r\n <input type=\"radio\" name=\"locale\" value=\"en\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In English</span>\r\n <input style=\"margin-left:1em\" type=\"radio\" name=\"locale\" value=\"ru\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In Russian</span>\r\n </div>\r\n <textarea data-drafts-id=\"CommentReplyFrame\" class=\"wysiwyg\" name=\"editContent\" rows=\"20\" style=\"width:99%;\"></textarea>\r\n <div class=\"error error__content\"></div>\r\n <div style=\"text-align:center;\">\r\n <input type=\"button\" name=\"preview\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Preview\"/>\r\n <input type=\"button\" name=\"save\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Save\"/>\r\n </div>\r\n</div>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n\r\nvar firstPreview10585 = true;\r\nvar lastPreviewContent10585 = '';\r\n\r\nif (!window.moveCommentRevision) {\r\n moveCommentRevision = function(e, dir) {\r\n var p = e.parent();\r\n var revisionCount = parseInt(p.attr(\"revisionCount\"));\r\n var revision = parseInt(p.attr(\"revision\"));\r\n var next = revision + dir;\r\n var commentId = p.attr(\"commentId\");\r\n if (next >= 1 && next <= revisionCount) {\r\n $.post(\r\n \"/data/comment-data\",\r\n {action: \"revision\", commentId: commentId, revision: next},\r\n function(json) {\r\n if (json.success == \"true\") {\r\n var parentDiv = e;\r\n\r\n while (parentDiv !== null && (parentDiv[0].nodeName.toLowerCase() !== \"td\" || !parentDiv.hasClass(\"right\"))) {\r\n parentDiv = parentDiv.parent();\r\n }\r\n\r\n if (parentDiv === null) {\r\n return;\r\n }\r\n\r\n parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\").html(json.content);\r\n Codeforces.setupSpoilers(parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\"));\r\n p.attr(\"revision\", next);\r\n p.find(\"span.revision\").text(next);\r\n if (next == 1) {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"visible\");\r\n }\r\n if (next == revisionCount) {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"visible\");\r\n }\r\n\r\n window.updateTypography();\r\n MathJax.Hub.Typeset();\r\n } else {\r\n alert(e.error);\r\n }\r\n },\r\n \"json\"\r\n );\r\n }\r\n };\r\n}\r\n\r\n$(\"div[commentableId=10585] a.leftRevision\").click(function () {\r\n window.moveCommentRevision($(this), -1);\r\n return false;\r\n});\r\n\r\n$(\"div[commentableId=10585] a.rightRevision\").click(function () {\r\n window.moveCommentRevision($(this), +1);\r\n return false;\r\n});\r\n\r\n\r\n\r\n });\n </script>\n\r\n\r\n <script src=\"//codeforces.org/s/81027/js/swfobject-2.2.min.js\" type=\"text/javascript\"></script>\n <script src=\"//codeforces.org/s/81027/js/ftaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n if (window.evercookie) {\n var ec = new evercookie({\n history: false,\n silverlight: false,\n baseurl: '',\n asseturi: '/assets',\n phpuri: '/2fdcd78',\n pngPath: '/eps',\n etagPath: '/ees',\n cachePath: '/ecs'\n });\n\n var randomNumber = function () {\n return Math.random().toString(36).substr(2);\n };\n\n var randomToken = function () {\n return (randomNumber() + randomNumber()).substring(0, 18);\n };\n\n window._ftaa = \"\";\n\n ec.get(\"70a7c28f3de\", function (value) {\n window._ftaa = value;\n if (!window._ftaa) {\n window._ftaa = randomToken();\n ec.set(\"70a7c28f3de\", window._ftaa);\n }\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n } else {\n window._ftaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\n <script src=\"//codeforces.org/s/81027/js/bfaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n var fpCallback = function() {\n Fingerprint2.get({}, function(components) {\n window._bfaa = Fingerprint2.x64hash128(components.map(function (pair) { return pair.value }).join(), 31);\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n };\n if (typeof Fingerprint2 !== 'undefined') {\n if (window.requestIdleCallback) {\n requestIdleCallback(fpCallback)\n } else {\n setTimeout(fpCallback, 500)\n }\n } else {\n window._bfaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"a.new-root-comment\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n\r\n $(\".comment-table .reply a\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".vote-for-comment\").mouseover(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").mouseout(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").click(function () {\r\n var vote = $(this);\r\n var commentId = $(this).parent().attr(\"commentid\");\r\n var commentRating = $(this).parent().attr(\"data-commentRating\");\r\n var direction = $(this).attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n $.post(\"/data/comment/vote\", {commentId: commentId, _tta: Codeforces.tta(), vote: direction, commentRating: commentRating}, function(data) {\r\n if (direction != 0 && !ownComment && data[\"success\"] == \"true\") {\r\n vote.parent().find(\".vote-for-comment\").attr(\"voteDirection\", 0);\r\n if (direction == 1)\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n else {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.closest(\".CommentVoteFrame\").find(\".ComplaintFrame\").css(\"display\", \"inline-block\");\r\n }\r\n vote.find(\"img\").attr(\"popacity\", \"1.0\");\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n vote.parent().find(\".commentRating\").html(data[\"commentRating\"]);\r\n }\r\n Codeforces.showMessage(data[\"message\"]);\r\n }, \"json\");\r\n return false;\r\n });\r\n\r\n $(\".negative-comment-vote\").closest(\".comment-table\").addClass(\"comment-bad\");\r\n\r\n $(\".troll-comment-vote\").closest(\".comment\").css(\"display\", \"none\");\r\n\r\n $(\".too-negative-comment-vote\").closest(\".comment-table\").each(function () {\r\n var e = $(this);\r\n e.addClass(\"comment-too-bad\");\r\n var commentId = e.attr(\"commentId\");\r\n $(\"<div class='bad-comment-replacement ttypography'>The comment is hidden because of too negative feedback, click <a href=# class=show-bad-comment-link>here</a> to view it</div>\").appendTo(\r\n e.find(\".right\")\r\n );\r\n e.find(\".comment-content\").hide();\r\n e.find(\".show-bad-comment-link\").click(function () {\r\n e.find(\".comment-content\").show();\r\n e.find(\".bad-comment-replacement\").hide();\r\n return false;\r\n });\r\n });\r\n });\n </script>\n </div>\r\n\r\n <style type=\"text/css\">\r\n .new-comments-box {\r\n padding: 0.5em;\r\n width: 22px;\r\n font-size: 1.3rem;\r\n font-weight: bold !important;\r\n\r\n position: fixed;\r\n top: 40%;\r\n right: 0;\r\n opacity: 0.2;\r\n color: white;\r\n text-align: center;\r\n\r\n border: 1px solid #222;\r\n background-color: #888 !important;\r\n border-radius: 3px;\r\n -moz-border-radius: 3px;\r\n -webkit-border-radius: 3px;\r\n }\r\n\r\n .new-comments-box:hover {\r\n opacity: 1;\r\n }\r\n\r\n .new-comments-box .dir:hover {\r\n background: #3B5998 !important;\r\n cursor: pointer;\r\n }\r\n </style>\r\n\r\n <div class=\"new-comments-box\" data-position=\"outside\" data-index=\"-1\" style=\"display: none;\">\r\n <div class=\"up dir\" title=\"Ctrl+Up\">↑<hr/>\r\n </div>\r\n <div class=\"info\" title=\"New comments\"></div>\r\n <div class=\"down dir\" title=\"Ctrl+Down\">\r\n <hr/>↓\r\n </div>\r\n </div>\r\n\r\n <script>\r\n $(\".show-archived-checkbox\").change(function () {\r\n const checked = $(this).is(\":checked\");\r\n $.post(\"/data/comment-data\", {action: \"setShowArchived\", checked}, function (json) {\r\n if (json[\"success\"] !== \"true\") {\r\n alert(json[\"error\"]);\r\n } else {\r\n if (checked) {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are now displayed\")\r\n } else {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are no longer displayed\")\r\n }\r\n }\r\n });\r\n return false;\r\n });\r\n\r\n function gotoComment(direction) {\r\n var box = $(\".new-comments-box\");\r\n var index = parseInt(box.attr(\"data-index\"));\r\n if (index == -1)\r\n index = 0;\r\n else\r\n index = Math.max(0, Math.min(parseInt(box.find(\".info\").text()) - 1, index + direction));\r\n box.attr(\"data-index\", index);\r\n var comment = $($(\".comment .highlight-blue[commentId]\").get(index));\r\n $('html, body').animate({\r\n 'scrollTop': Math.max(0, comment.offset().top - ($(window).height() - comment.height()) / 2)\r\n });\r\n return false;\r\n }\r\n\r\n $(\".new-comments-box .down\").click(function () {\r\n return gotoComment(1);\r\n });\r\n\r\n $(\".new-comments-box .up\").click(function () {\r\n return gotoComment(-1);\r\n });\r\n\r\n $(document).keydown(function (e) {\r\n var code = (e.keyCode ? e.keyCode : e.which);\r\n if (e.ctrlKey) {\r\n if (code == 38 || code == 40) {\r\n gotoComment(code - 39);\r\n }\r\n }\r\n });\r\n\r\n var newCommentCount = $(\".comment .highlight-blue[commentId]\").length;\r\n if (newCommentCount > 0) {\r\n $(\".new-comments-box .info\").text(newCommentCount);\r\n $(\".new-comments-box\").show();\r\n }\r\n\r\n $('table.comment-table').mouseenter(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").addClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n\r\n $('table.comment-table').mouseleave(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").removeClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n </script>\r\n\r\n\r\n\r\n <script>\r\n function adjustTopicComplainFrames() {\r\n let topicIds = [];\r\n\r\n $(\".has-topic-id\").each(function () {\r\n const $this = $(this);\r\n const topicId = $this.attr(\"topicId\");\r\n if (topicId) {\r\n topicIds.push(topicId);\r\n }\r\n });\r\n\r\n $.post(\"/data/topics\", {\r\n action: \"findComplainableTopicIds\",\r\n topicIds: topicIds.join(\",\")\r\n }, function (json) {\r\n if (json[\"success\"] === \"true\") {\r\n for (const topicId of json[\"complainableTopicIds\"].split(\",\")) {\r\n $(\".has-topic-id[topicId=\" + topicId + \"]\").each(function () {\r\n $(this).find(\".meta .ComplaintFrame\").css(\"display\", \"inline-block\");\r\n });\r\n }\r\n }\r\n }, \"json\");\r\n }\r\n\r\n $(function () {\r\n adjustTopicComplainFrames();\r\n })\r\n </script>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-10569\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 10569, _tta: Codeforces.tta(), topicRevisionId: 36378, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-10569\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 10569, _tta: Codeforces.tta(), topicRevisionId: 36378, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n </div>\r\n </div>\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 22:13:04</span> (h1).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/81027/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/81027/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/81027/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/81027/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-81027.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'8128758f5b7075a7',t:'MTY5NjcwNTk4NC4yOTcwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"}}},{"rowIdx":1947,"cells":{"problem_id":{"kind":"string","value":"385D"},"contest":{"kind":"string","value":"385"},"problem":{"kind":"string","value":"D"},"lang":{"kind":"string","value":"en"},"problem_title":{"kind":"string","value":"D. Bear and Floodlight"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">D. Bear and Floodlight</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>4 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>One day a bear lived on the <span class=\"tex-span\"><i>Oxy</i></span> axis. He was afraid of the dark, so he couldn't move at night along the plane points that aren't lit. One day the bear wanted to have a night walk from his house at point <span class=\"tex-span\">(<i>l</i>, 0)</span> to his friend's house at point <span class=\"tex-span\">(<i>r</i>, 0)</span>, along the segment of length <span class=\"tex-span\">(<i>r</i> - <i>l</i>)</span>. Of course, if he wants to make this walk, he needs each point of the segment to be lit. That's why the bear called his friend (and yes, in the middle of the night) asking for a very delicate favor.</p><p>The <span class=\"tex-span\"><i>Oxy</i></span> axis contains <span class=\"tex-span\"><i>n</i></span> floodlights. Floodlight <span class=\"tex-span\"><i>i</i></span> is at point <span class=\"tex-span\">(<i>x</i><sub class=\"lower-index\"><i>i</i></sub>, <i>y</i><sub class=\"lower-index\"><i>i</i></sub>)</span> and can light any angle of the plane as large as <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> degree with vertex at point <span class=\"tex-span\">(<i>x</i><sub class=\"lower-index\"><i>i</i></sub>, <i>y</i><sub class=\"lower-index\"><i>i</i></sub>)</span>. The bear asked his friend to turn the floodlights so that he (the bear) could go as far away from his house as possible during the walking along the segment. His kind friend agreed to fulfill his request. And while he is at it, the bear wonders: what is the furthest he can go away from his house? Hep him and find this distance.</p><p>Consider that the plane has no obstacles and no other light sources besides the floodlights. The bear's friend cannot turn the floodlights during the bear's walk. Assume that after all the floodlights are turned in the correct direction, the bear goes for a walk and his friend goes to bed.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains three space-separated integers <span class=\"tex-span\"><i>n</i></span>, <span class=\"tex-span\"><i>l</i></span>, <span class=\"tex-span\"><i>r</i></span> <span class=\"tex-span\">(1 ≤ <i>n</i> ≤ 20; - 10<sup class=\"upper-index\">5</sup> ≤ <i>l</i> ≤ <i>r</i> ≤ 10<sup class=\"upper-index\">5</sup>)</span>. The <span class=\"tex-span\"><i>i</i></span>-th of the next <span class=\"tex-span\"><i>n</i></span> lines contain three space-separated integers <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span>, <span class=\"tex-span\"><i>y</i><sub class=\"lower-index\"><i>i</i></sub></span>, <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> <span class=\"tex-span\">( - 1000 ≤ <i>x</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 1000; 1 ≤ <i>y</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 1000; 1 ≤ <i>a</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 90)</span> — the floodlights' description. </p><p>Note that two floodlights can be at the same point of the plane.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print a single real number — the answer to the problem. The answer will be considered correct if its relative or absolute error doesn't exceed <span class=\"tex-span\">10<sup class=\"upper-index\"> - 6</sup></span>.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>2 3 5<br/>3 1 45<br/>5 1 45<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>2.000000000<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>1 0 1<br/>1 1 30<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>0.732050808<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>1 0 1<br/>1 1 45<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1.000000000<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>1 0 2<br/>0 2 90<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>2.000000000<br/></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>In the first sample, one of the possible solutions is: </p><center> <img class=\"tex-graphics\" src=\"https://espresso.codeforces.com/768ca3d55c62cd11f4734906353a59b19b7e23fc.png\" style=\"max-width: 100.0%;max-height: 100.0%;\"/> </center><p>In the second sample, a single solution is: </p><center> <img class=\"tex-graphics\" src=\"https://espresso.codeforces.com/a6c94deead376818fb1eaaeca5338780a62747d4.png\" style=\"max-width: 100.0%;max-height: 100.0%;\"/> </center><p>In the third sample, a single solution is: </p><center> <img class=\"tex-graphics\" src=\"https://espresso.codeforces.com/125e5e085409a511911f19293268214cab39a9e0.png\" style=\"max-width: 100.0%;max-height: 100.0%;\"/> </center></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"9d2563f08e0d00c1530dbe0832e1ada8\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - D - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"3200a641fa0ca6f78af7a41b57e5016ab7be9096\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - D - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/73366/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/73366/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/73366/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/73366/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/73366/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/73366/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/73366/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/73366/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/73366/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/73366/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/73366/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/73366/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/73366/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/73366/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/sidebar-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/a037fe51637846d9c7c725713cd840ea/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='9d2563f08e0d00c1530dbe0832e1ada8'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/73366/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/73366/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fcontest%2F385%2Fproblem%2FD%3Flocale%3Den\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"current\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='9d2563f08e0d00c1530dbe0832e1ada8'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:100%;\"><a style=\"color: black\" href=\"/contest/385\">Codeforces Round 226 (Div. 2)</a></th>\n </tr>\n <tr>\n <td class=\"left bottom\" colspan=\"1\"><span class=\"contest-state-phase\">Finished</span></td>\n </tr>\n </tbody>\n </table>\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Practice?\n <div class=\"top-links\">\n </div>\n </div>\n<div>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Want to solve the contest problems after the official contest ends? Just register for practice and you will be able to submit solutions.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"\" method=\"post\"><input type='hidden' name='csrf_token' value='9d2563f08e0d00c1530dbe0832e1ada8'/>\r\n <input type=\"hidden\" name=\"action\" value=\"registerForPractice\"/>\r\n <input type=\"submit\" name=\"submit\" value=\"Register for practice\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div> \r\n</div>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox ContestVirtualFrame borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Virtual participation <i class=\"sidebar-caption-icon las la-angle-down\"></i>\r\n\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\" \"\r\n\r\n data-page-url=\"/data/sidebarFrames\"\r\n\r\n>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests.\n\nIf you've seen these problems, a virtual contest is not for you - solve these problems in the archive.\n\nIf you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.\n\nNever use someone else's code, read the tutorials or communicate with other person during a virtual contest.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"/contest/385/virtual\" method=\"get\">\r\n <input type=\"submit\" name=\"submit\" value=\"Start virtual contest\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div>\r\n</div>\r\n <script>\r\n $(function () {\r\n $(\".ContestVirtualFrame .sidebar-caption-icon\").click(function() {\r\n $(this).toggleClass(\"la-angle-down la-angle-right\");\r\n const $target = $(this).parent().next();\r\n $target.toggle();\r\n const dataPageUrl = $target.attr(\"data-page-url\");\r\n const collapsed = $(this).hasClass(\"la-angle-right\");\r\n const params = {\r\n action: \"setCollapsed\",\r\n sidebarFrameSimpleClassName: \"ContestVirtualFrame\",\r\n collapsed\r\n };\r\n $.each($target[0].attributes, function(i, a) {\r\n const name = a.name;\r\n if (name.startsWith(\"data-extra-key-\")) {\r\n const key = a.value;\r\n const keyIndex = parseInt(name.substring(\"data-extra-key-\".length));\r\n const value = $target.attr(\"data-extra-value-\" + keyIndex);\r\n params[key] = value;\r\n }\r\n });\r\n $.post(dataPageUrl, params, function (result) {\r\n if (result[\"success\"] !== \"true\") {\r\n Codeforces.showMessage(\"Failed to save collapsed state.\");\r\n }\r\n }, \"json\");\r\n return false;\r\n });\r\n })\r\n </script>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Problem tags\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Bitmasks\">\r\n bitmasks\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Dynamic programming\">\r\n dp\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Geometry, computational geometry\">\r\n geometry\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Difficulty\">\r\n *2200\r\n</span>\r\n </div>\n <div style=\"clear:both;text-align:right;font-size:1.1rem;\">\r\n <span title=\"Please login into the Codeforces\" class=\"notice\">No tag edit access</span>\r\n </div>\r\n</div>\r\n </div>\n\r\n<form id=\"addTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='9d2563f08e0d00c1530dbe0832e1ada8'/>\r\n <input name=\"action\" type=\"hidden\" value=\"addTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"5934\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<form id=\"removeTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='9d2563f08e0d00c1530dbe0832e1ada8'/>\r\n <input name=\"action\" type=\"hidden\" value=\"removeTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"5934\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<script type=\"text/javascript\">\r\n $(\".tag-box img\").click(function () {\r\n var tagName = $(this).attr(\"value\");\r\n Codeforces.confirm(\"Are you sure you want to remove this tag?\", function () {\r\n $(\"#removeTagForm input[name=tagName]\").val(tagName);\r\n $(\"#removeTagForm\").submit();\r\n }, function () {\r\n }, \"Yes\", \"No\");\r\n });\r\n\r\n $(\"#addTagLink\").click(function () {\r\n $(this).hide();\r\n $(\"#addTagLabel\").show();\r\n return false;\r\n });\r\n\r\n $(\"#addTagSelect\").change(function () {\r\n var tagName = $(this).val();\r\n if (tagName === \"\") {\r\n $(\"#addTagLabel\").hide();\r\n $(\"#addTagLink\").show();\r\n } else {\r\n $(\"#addTagForm input[name=tagName]\").val(tagName);\r\n $(\"#addTagForm\").submit();\r\n }\r\n });\r\n</script>\r\n\r\n<style type=\"text/css\">\r\n#new-resource-form tr td {\r\npadding-top: 0.5em;\r\n}\r\n#new-resource-form input:not([type=\"submit\"]) {\r\nfont-size: 0.8em;\r\n}\r\n#new-resource-form select {\r\nfont-size: 0.8em;\r\n}\r\n.new-resource-error {\r\nfont-size: 0.8em;\r\n}\r\n.resource-locale {\r\ncolor: #666;\r\nfont-family: Consolas, \"Andale Mono WT\", \"Andale Mono\", \"Lucida Console\", \"Lucida Sans Typewriter\", \"DejaVu Sans Mono\", \"Bitstream Vera Sans Mono\", \"Liberation Mono\", \"Nimbus Mono L\", Monaco, \"Courier New\", Courier, monospace;\r\n}\r\n</style>\r\n<div class=\"roundbox sidebox sidebar-menu borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Contest materials\n<div class=\"top-links\">\n</div>\n</div>\n<ul>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/10512\" title=\"Codeforces Round #226 (Div. 2)\" target=\"_blank\">Announcement</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"2193:2194\" resourceName=\"Announcement\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/10514\" title=\"Codeforces Round #226 (Div. 2) — Editorial\" target=\"_blank\">Tutorial</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"2197:2198\" resourceName=\"Tutorial\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n</ul>\r\n</div></div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li class=\"current selectedLava\"><a\r\n href=\"/contest/385\">Problems</a></li>\r\n <li><a\r\n href=\"/contest/385/submit\">Submit Code</a></li>\r\n <li><a\r\n href=\"/contest/385/my\">My Submissions</a></li>\r\n <li><a\r\n href=\"/contest/385/status\">Status</a></li>\r\n <li><a\r\n href=\"/contest/385/hacks\">Hacks</a></li>\r\n <li><a\r\n href=\"/contest/385/room/1\">Room</a></li>\r\n <li><a\r\n href=\"/contest/385/standings\">Standings</a></li>\r\n <li><a\r\n href=\"/contest/385/customtest\">Custom Invocation</a></li>\r\n</ul>\r\n</div>\n\r\n <style>\r\n #facebox .content:has(.diff-popup) {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n }\r\n\r\n .testCaseMarker {\r\n position: absolute;\r\n font-weight: bold;\r\n font-size: 1rem;\r\n }\r\n\r\n .diff-popup {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n display: none;\r\n overflow: auto;\r\n }\r\n\r\n .input-output-copier {\r\n font-size: 1.2rem;\r\n float: right;\r\n color: #888 !important;\r\n cursor: pointer;\r\n border: 1px solid rgb(185, 185, 185);\r\n padding: 3px;\r\n margin: 1px;\r\n line-height: 1.1rem;\r\n text-transform: none;\r\n }\r\n\r\n .input-output-copier:hover {\r\n background-color: #def;\r\n }\r\n\r\n .test-explanation textarea {\r\n width: 100%;\r\n height: 1.5em;\r\n }\r\n\r\n .pending-submission-message {\r\n color: darkorange !important;\r\n }\r\n </style>\r\n <script>\r\n const OPENING_SPACE = String.fromCharCode(1001);\r\n const CLOSING_SPACE = String.fromCharCode(1002);\r\n\r\n const nodeToText = function (node, pre) {\r\n let result = [];\r\n\r\n if (node.tagName === \"SCRIPT\" || node.tagName === \"math\"\r\n || (node.classList && node.classList.contains(\"input-output-copier\")))\r\n return [];\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(OPENING_SPACE);\r\n }\r\n\r\n if (node.nodeType === Node.TEXT_NODE) {\r\n let s = node.textContent;\r\n if (!pre) {\r\n s = s.replace(/\\s+/g, \" \");\r\n }\r\n if (s.length > 0) {\r\n result.push(s);\r\n }\r\n }\r\n\r\n if (pre && node.tagName === \"BR\") {\r\n result.push(\"\\n\");\r\n }\r\n\r\n node.childNodes.forEach(function (child) {\r\n result.push(nodeToText(child, node.tagName === \"PRE\").join(\"\"));\r\n });\r\n\r\n if (node.tagName === \"DIV\"\r\n || node.tagName === \"P\"\r\n || node.tagName === \"PRE\"\r\n || node.tagName === \"UL\"\r\n || node.tagName === \"LI\"\r\n ) {\r\n result.push(\"\\n\");\r\n }\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(CLOSING_SPACE);\r\n }\r\n\r\n return result;\r\n }\r\n\r\n const isSpecial = function (c) {\r\n return c === ',' || c === '.' || c === ';' || c === ')' || c === ' ';\r\n }\r\n\r\n const convertStatementToText = function(statmentNode) {\r\n const text = nodeToText(statmentNode, false).join(\"\").replace(/ +/g, \" \").replace(/\\n\\n+/g, \"\\n\\n\");\r\n let result = [];\r\n for (let i = 0; i < text.length; i++) {\r\n const c = text.charAt(i);\r\n if (c === OPENING_SPACE) {\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"D\" data-uuid=\"ps_ea4d2d76d22cfd7dad91f1fd3914599f82ad1ec3\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">D. Bear and Floodlight</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>4 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>One day a bear lived on the <span class=\"tex-span\"><i>Oxy</i></span> axis. He was afraid of the dark, so he couldn't move at night along the plane points that aren't lit. One day the bear wanted to have a night walk from his house at point <span class=\"tex-span\">(<i>l</i>, 0)</span> to his friend's house at point <span class=\"tex-span\">(<i>r</i>, 0)</span>, along the segment of length <span class=\"tex-span\">(<i>r</i> - <i>l</i>)</span>. Of course, if he wants to make this walk, he needs each point of the segment to be lit. That's why the bear called his friend (and yes, in the middle of the night) asking for a very delicate favor.</p><p>The <span class=\"tex-span\"><i>Oxy</i></span> axis contains <span class=\"tex-span\"><i>n</i></span> floodlights. Floodlight <span class=\"tex-span\"><i>i</i></span> is at point <span class=\"tex-span\">(<i>x</i><sub class=\"lower-index\"><i>i</i></sub>, <i>y</i><sub class=\"lower-index\"><i>i</i></sub>)</span> and can light any angle of the plane as large as <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> degree with vertex at point <span class=\"tex-span\">(<i>x</i><sub class=\"lower-index\"><i>i</i></sub>, <i>y</i><sub class=\"lower-index\"><i>i</i></sub>)</span>. The bear asked his friend to turn the floodlights so that he (the bear) could go as far away from his house as possible during the walking along the segment. His kind friend agreed to fulfill his request. And while he is at it, the bear wonders: what is the furthest he can go away from his house? Hep him and find this distance.</p><p>Consider that the plane has no obstacles and no other light sources besides the floodlights. The bear's friend cannot turn the floodlights during the bear's walk. Assume that after all the floodlights are turned in the correct direction, the bear goes for a walk and his friend goes to bed.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains three space-separated integers <span class=\"tex-span\"><i>n</i></span>, <span class=\"tex-span\"><i>l</i></span>, <span class=\"tex-span\"><i>r</i></span> <span class=\"tex-span\">(1 ≤ <i>n</i> ≤ 20; - 10<sup class=\"upper-index\">5</sup> ≤ <i>l</i> ≤ <i>r</i> ≤ 10<sup class=\"upper-index\">5</sup>)</span>. The <span class=\"tex-span\"><i>i</i></span>-th of the next <span class=\"tex-span\"><i>n</i></span> lines contain three space-separated integers <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span>, <span class=\"tex-span\"><i>y</i><sub class=\"lower-index\"><i>i</i></sub></span>, <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> <span class=\"tex-span\">( - 1000 ≤ <i>x</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 1000; 1 ≤ <i>y</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 1000; 1 ≤ <i>a</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 90)</span> — the floodlights' description. </p><p>Note that two floodlights can be at the same point of the plane.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print a single real number — the answer to the problem. The answer will be considered correct if its relative or absolute error doesn't exceed <span class=\"tex-span\">10<sup class=\"upper-index\"> - 6</sup></span>.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>2 3 5<br />3 1 45<br />5 1 45<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>2.000000000<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>1 0 1<br />1 1 30<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>0.732050808<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>1 0 1<br />1 1 45<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1.000000000<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>1 0 2<br />0 2 90<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>2.000000000<br /></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>In the first sample, one of the possible solutions is: </p><center> <img class=\"tex-graphics\" src=\"https://espresso.codeforces.com/768ca3d55c62cd11f4734906353a59b19b7e23fc.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> </center><p>In the second sample, a single solution is: </p><center> <img class=\"tex-graphics\" src=\"https://espresso.codeforces.com/a6c94deead376818fb1eaaeca5338780a62747d4.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> </center><p>In the third sample, a single solution is: </p><center> <img class=\"tex-graphics\" src=\"https://espresso.codeforces.com/125e5e085409a511911f19293268214cab39a9e0.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> </center></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=D]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== statementText) {\r\n $problem.find(\".diff-notifier\").show();\r\n\r\n $problem.find(\".diff-notifier-close\").click(function() {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n $problem.find(\".diff-notifier\").hide();\r\n });\r\n\r\n $problem.find(\"a.view-changes\").click(function() {\r\n $.post(\"/data/diff\", {action: \"getDiff\", a: previousStatementText, b: statementText}, function (result) {\r\n if (result[\"success\"] === \"true\") {\r\n Codeforces.facebox(\".diff-popup\", \"//codeforces.org/s/73366\");\r\n $(\"#facebox .diff-popup\").html(result[\"diff\"]);\r\n }\r\n }, \"json\");\r\n });\r\n }\r\n } else {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n }\r\n });\r\n });\r\n </script>\r\n\r\n\r\n<script type=\"text/javascript\">\r\n $(document).ready(function () {\r\n window.changedTests = new Set();\r\n\r\n function endsWith(string, suffix) {\r\n return string.indexOf(suffix, string.length - suffix.length) !== -1;\r\n }\r\n\r\n const inputFileDiv = $(\"div.input-file\");\r\n const inputFile = inputFileDiv.text();\r\n const outputFileDiv = $(\"div.output-file\");\r\n const outputFile = outputFileDiv.text();\r\n\r\n\r\n if (!endsWith(inputFile, \"standard input\")\r\n && !endsWith(inputFile, \"standard input\")) {\r\n inputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n if (!endsWith(outputFile, \"standard output\")\r\n && !endsWith(outputFile, \"standard output\")) {\r\n outputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n const titleDiv = $(\"div.header div.title\");\r\n\r\n\r\n\r\n String.prototype.replaceAll = function (search, replace) {\r\n return this.split(search).join(replace);\r\n };\r\n\r\n $(\".sample-test .title\").each(function () {\r\n const preId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n const cpyId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n\r\n $(this).parent().find(\"pre\").attr(\"id\", preId);\r\n const $copy = $(\"<div title='Copy' data-clipboard-target='#\" + preId + \"' id='\" + cpyId + \"' class='input-output-copier'>Copy</div>\");\r\n $(this).append($copy);\r\n\r\n const clipboard = new Clipboard('#' + cpyId, {\r\n text: function (trigger) {\r\n const pre = document.querySelector('#' + preId);\r\n const lines = pre.querySelectorAll(\".test-example-line\");\r\n return Codeforces.filterClipboardText(pre.innerText, lines.length);\r\n }\r\n });\r\n\r\n const isInput = $(this).parent().hasClass(\"input\");\r\n\r\n clipboard.on('success', function (e) {\r\n if (isInput) {\r\n Codeforces.showMessage(\"The example input has been copied into the clipboard\");\r\n } else {\r\n Codeforces.showMessage(\"The example output has been copied into the clipboard\");\r\n }\r\n e.clearSelection();\r\n });\r\n });\r\n\r\n $(\".test-form-item input\").change(function () {\r\n addPendingSubmissionMessage($($(this).closest(\"form\")), \"You changed the answer, do not forget to submit it if you want to save the changes\");\r\n const index = $(this).closest(\".problemindexholder\").attr(\"problemindex\");\r\n let test = \"\";\r\n $(this).closest(\"form input\").each(function () {\r\n const test_ = $(this).attr(\"name\");\r\n if (test_ && test_.substring(0, 4) === \"test\") {\r\n test = test_;\r\n }\r\n });\r\n if (index.length > 0 && test.length > 0) {\r\n const indexTest = index + \"::\" + test;\r\n window.changedTests.add(indexTest);\r\n }\r\n });\r\n\r\n $(window).on('beforeunload', function () {\r\n if (window.changedTests.size > 0) {\r\n return 'Dialog text here';\r\n }\r\n });\r\n\r\n autosize($('.test-explanation textarea'));\r\n\r\n $(\".test-example-line\").hover(function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n let top = 1E20;\r\n let left = 1E20;\r\n let problem = $(this).closest(\".problemindexholder\");\r\n $(this).closest(\".input\").find(\".\" + clazz).css(\"background-color\", \"#FFFDE7\").each(function() {\r\n top = Math.min(top, $(this).offset().top);\r\n left = Math.min(left, $(this).offset().left);\r\n });\r\n let testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n if (testCaseMarker.length === 0) {\r\n const html = \"<div class=\\\"testCaseMarker testCaseMarker_\" + end + \" notice\\\"></div>\";\r\n problem.append($(html));\r\n testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n }\r\n if (testCaseMarker) {\r\n testCaseMarker.show()\r\n .offset({top, left: left - 20})\r\n .text(end);\r\n }\r\n }\r\n }\r\n });\r\n }, function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n $(\".\" + clazz).css(\"background-color\", \"\");\r\n $(this).closest(\".problemindexholder\").find(\".testCaseMarker_\" + end).hide();\r\n }\r\n }\r\n });\r\n });\r\n\r\n });\r\n</script>\r\n\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 05:38:14</span> (j3).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/73366/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/73366/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/73366/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/73366/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-73366.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'8122c44d2d7c7b2f',t:'MTY5NjY0NjI5NC42OTUwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"},"long_tags":{"kind":"string","value":"[\"Bitmasks\", \"Dynamic programming\", \"Geometry, computational geometry\"]"},"short_tags":{"kind":"string","value":"[\"bitmasks\", \"dp\", \"geometry\", \"*2200\"]"},"tutorial_link":{"kind":"string","value":"https://codeforces.com/blog/entry/10514"},"tutorial_page":{"kind":"string","value":"\r\n\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"b0edd04b6e615eea61c4a67daabca579\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"h1\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Codeforces Round #226 (Div. 2) — Editorial - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n \n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Codeforces Round #226 (Div. 2) — Editorial - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/81027/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/81027/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/81027/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/81027/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/81027/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/81027/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/81027/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/81027/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/81027/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/81027/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/81027/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/81027/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/81027/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/81027/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/573cedc6b04c15481941f418269f4057/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='b0edd04b6e615eea61c4a67daabca579'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/81027/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fblog%2Fentry%2F10514\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='b0edd04b6e615eea61c4a67daabca579'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Pay attention\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n <div style=\"text-align:center;border-bottom: 1px solid rgb(185, 185, 185);margin:0 -0.5em 0.5em -0.5em;padding: 0 1em 0.5em 1em;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 1, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:51:56</span><br/><a href=\"/contestRegistration/1876\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n <div style=\"text-align:center;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 2, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:51:56</span><br/><a href=\"/contestRegistration/1877\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='b0edd04b6e615eea61c4a67daabca579'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n </label>\r\n </div>\r\n <div style=\"padding: 0 1em 1em 1em;text-align:right;\">\r\n <input style=\"height:1.65em;padding:0 0.75em;\" type=\"submit\" value=\"Find\"/>\r\n </div>\r\n </form>\r\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".handleBox\").autocomplete(\"/data/handles\", {\r\n delay: 200,\r\n width: 200,\r\n selectFirst: false,\r\n matchContains: true,\r\n minChars: 3\r\n });\r\n $(\".handleForm\").attr(\"autocomplete\", \"off\").submit(function () {\r\n var link = \"/profile/userHandle\".replace(\r\n \"userHandle\", $(this).find(\".handleBox\").val()\r\n );\r\n window.location = link;\r\n return false;\r\n });\r\n });\n </script>\n\r\n\r\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Recent actions\n <div class=\"top-links\">\n </div>\n </div>\n <div class=\"recent-actions\">\r\n <ul>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/121073\">Meta Hacker Cup 2023 Round 1</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/.Danet\" title=\"Expert .Danet\" class=\"rated-user user-blue\">.Danet</a> →\r\n <a href=\"/blog/entry/121172\">[TLE on pretest1]</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\" class=\"rated-user user-red\">Pyqe</a> →\r\n <a href=\"/blog/entry/121025\">Codeforces Round #902 (Div. 1, Div. 2, based on COMPFEST 15 — Final Round)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pranshu_Pandya\" title=\"Specialist Pranshu_Pandya\" class=\"rated-user user-cyan\">Pranshu_Pandya</a> →\r\n <a href=\"/blog/entry/121171\">An Interesting Tree Problem</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/sszcdjr\" title=\"Master sszcdjr\" class=\"rated-user user-orange\">sszcdjr</a> →\r\n <a href=\"/blog/entry/119859\">Codeforces Round 896 (Div. 1, Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/119880\">It's Happening! Meta Hacker Cup 2023 Schedule</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/DaviddeGea1\" title=\"Expert DaviddeGea1\" class=\"rated-user user-blue\">DaviddeGea1</a> →\r\n <a href=\"/blog/entry/70917\">Number of ways of dividing an array into 2 parts such that sum of each part is > k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bekh\" title=\"Master Bekh\" class=\"rated-user user-orange\">Bekh</a> →\r\n <a href=\"/blog/entry/74245\">Questions and doubts regarding Aliens DP trick</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a> →\r\n <a href=\"/blog/entry/8192\">Codeforces Round #190 — Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/hocky\" title=\"Candidate Master hocky\" class=\"rated-user user-violet\">hocky</a> →\r\n <a href=\"/blog/entry/95323\">FBHC wuining uw Day? Incwease uw stacc size! (ㅅ´ ˘ `)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/liouzhou_101\" title=\"International Master liouzhou_101\" class=\"rated-user user-orange\">liouzhou_101</a> →\r\n <a href=\"/blog/entry/87598\">Editorial of Codeforces Round #700</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/yeon_gist\" title=\"Newbie yeon_gist\" class=\"rated-user user-gray\">yeon_gist</a> →\r\n <a href=\"/blog/entry/121170\">plusMinusPermutation computing error</a>\r\n <img alt=\"Text created or updated\" title=\"Text created or updated\" src=\"//codeforces.org/s/81027/images/icons/x-update-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/altforminuscontribution\" title=\"Newbie altforminuscontribution\" class=\"rated-user user-gray\">altforminuscontribution</a> →\r\n <a href=\"/blog/entry/121162\">My screen get unexpectedly big, what should I do</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/atcoder_official\" title=\"Unrated, atcoder_official\" class=\"rated-user user-black\">atcoder_official</a> →\r\n <a href=\"/blog/entry/121120\">We will hold UNIQUE VISION Programming Contest 2023 Autumn(AtCoder Beginner Contest 323)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/YouStill_DontKnowMeYet\" title=\"Candidate Master YouStill_DontKnowMeYet\" class=\"rated-user user-violet\">YouStill_DontKnowMeYet</a> →\r\n <a href=\"/blog/entry/117659\">[GYM] Al-Baath Collegiate Programming Contest 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/ankancool\" title=\"Expert ankancool\" class=\"rated-user user-blue\">ankancool</a> →\r\n <a href=\"/blog/entry/121136\">Invitation to AstroByte 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/GeZhiyuan\" title=\"Grandmaster GeZhiyuan\" class=\"rated-user user-red\">GeZhiyuan</a> →\r\n <a href=\"/blog/entry/120943\">Codeforces Round 901 (Div. 1, Div. 2) Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a> →\r\n <a href=\"/blog/entry/120772\">PSA: Increase your stack size before the Meta Hacker Cup, here's how</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/dino_merlin\" title=\"Expert dino_merlin\" class=\"rated-user user-blue\">dino_merlin</a> →\r\n <a href=\"/blog/entry/121145\">Intuitive approach for CEOI Kangaroo?</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/icecuber\" title=\"Grandmaster icecuber\" class=\"rated-user user-red\">icecuber</a> →\r\n <a href=\"/blog/entry/70018\">CSES DP section editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bn00b\" title=\"Newbie Bn00b\" class=\"rated-user user-gray\">Bn00b</a> →\r\n <a href=\"/blog/entry/98820\">[FEATURE REQUEST : ATCODER] TOPICS TAGS AND SORTING BY SOLVE COUNT</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a> →\r\n <a href=\"/blog/entry/121163\">AtCoder Regular Contest 166 Announcement</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/windva\" title=\"Grandmaster windva\" class=\"rated-user user-red\">windva</a> →\r\n <a href=\"/blog/entry/120644\">Codeforces Round 899 (Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Misa-Misa\" title=\"Expert Misa-Misa\" class=\"rated-user user-blue\">Misa-Misa</a> →\r\n <a href=\"/blog/entry/121157\">Someone please help me understand this.</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/shivam565\" title=\"Specialist shivam565\" class=\"rated-user user-cyan\">shivam565</a> →\r\n <a href=\"/blog/entry/108348\">Total number of subarrays with sum atmost k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n </ul>\r\n </div>\r\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/recent-actions\">Detailed →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n</div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li><a\r\n href=\"/profile/CleRIC\">CleRIC</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/CleRIC\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/CleRIC\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/CleRIC\">Submissions</a></li>\r\n <li><a\r\n href=\"/groups/with/CleRIC\">Groups</a></li>\r\n <li><a\r\n href=\"/contests/with/CleRIC\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/CleRIC\">Problemsetting</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/CleRIC\" style=\"text-decoration:none;color:black !important;\">CleRIC's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"10569\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/10514\"> <p>Codeforces Round #226 (Div. 2) — Editorial</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/CleRIC\" title=\"Candidate Master CleRIC\" class=\"rated-user user-violet\">CleRIC</a>,\r\n <span class=\"format-humantime\" title=\"Jan/23/2014 19:33\">10 years ago</span>,\r\n translation,\r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p><a href=\"/contest/385/problem/A\" title=\"Codeforces Round 226 (Div. 2)\">385A - Bear and Raspberry</a></p><p>In this task required to understand that the answer max(<span class=\"tex-span\"><i>a</i>[<i>i</i>] - <i>a</i>[<i>i</i> - 1] - <i>c</i></span>),<span class=\"tex-span\"><i>i</i></span> = <span class=\"tex-span\">2..<i>n</i></span> and don't forget that the answer not negative as Bear can not borrow in the debt barrel of honey.</p><p><a href=\"/contest/385/problem/B\" title=\"Codeforces Round 226 (Div. 2)\">385B - Bear and Strings</a></p><p>In this problem you could write a better solution than the naive. To do this, you can iterate through the first cycle of the left index <span class=\"tex-span\"><i>l</i></span> considered substring and the second cycle of the right index <span class=\"tex-span\"><i>r</i></span> considered substring <span class=\"tex-span\">(<i>l</i> ≤ <i>r</i>)</span>. If any position has been substring "bear", means all the strings <span class=\"tex-span\"><i>x</i>(<i>l</i>, <i>j</i>)</span> <span class=\"tex-span\">(<i>i</i> ≤ <i>j</i>)</span>, also contain "bear" as a substring. So we can add to the answer <span class=\"tex-span\">|<i>s</i>| - <i>j</i> + 1</span> and exit from the second cycle. Also needed to understand, that if the string <span class=\"tex-span\"><i>x</i>(<i>l</i>, <i>j</i>)</span> was not a substring "bear", then in row <span class=\"tex-span\"><i>x</i>(<i>l</i>, <i>j</i> + 1)</span> substring "bear" could appear only in the last four characters.</p><p><a href=\"/contest/385/problem/C\" title=\"Codeforces Round 226 (Div. 2)\">385C - Bear and Prime Numbers</a></p><p>In order to solve given problem, contestant should solve several subproblems :</p><p>1) First one is to compute amount of entries of each natural number between <span class=\"tex-span\">2</span> and <span class=\"tex-span\">10<sup class=\"upper-index\">7</sup></span> in given list. This subproblem can be solved by creating array <span class=\"tex-span\"><i>count</i></span> of <span class=\"tex-span\">10<sup class=\"upper-index\">7</sup></span> elements and increasing corresponding element when scanning input.</p><p>2) Second one is to compute <span class=\"tex-span\"><i>f</i>(<i>n</i>)</span>.</p><p>First of all, we need to find all primes less than <span class=\"tex-span\">10<sup class=\"upper-index\">7</sup></span> and then for each prime <span class=\"tex-span\"><i>n</i></span> compute <span class=\"tex-span\"><i>f</i>(<i>n</i>)</span>.</p><p>How to compute <span class=\"tex-span\"><i>f</i>(2)</span>? We should sum <span class=\"tex-span\"><i>count</i>[2]</span>,<span class=\"tex-span\"><i>count</i>[4]</span>,<span class=\"tex-span\"><i>count</i>[6]</span>,<span class=\"tex-span\"><i>count</i>[8]</span>,...</p><p>How to compute <span class=\"tex-span\"><i>f</i>(5)</span>? We should sum <span class=\"tex-span\"><i>count</i>[5]</span>,<span class=\"tex-span\"><i>count</i>[10]</span>,<span class=\"tex-span\"><i>count</i>[15]</span>,<span class=\"tex-span\"><i>count</i>[20]</span>,...</p><p>How to compute <span class=\"tex-span\"><i>f</i>(<i>n</i>)</span>? We should sum <span class=\"tex-span\"><i>count</i>[<i>n</i>]</span>,<span class=\"tex-span\"><i>count</i>[2·<i>n</i>]</span>,<span class=\"tex-span\"><i>count</i>[3·<i>n</i>]</span>,<span class=\"tex-span\"><i>count</i>[4·<i>n</i>]</span>,...</p><p>It can be seen that given algo is very similar to Sieve of Eratosthenes. (Info here <a href=\"http://e-maxx.ru/algo/eratosthenes_sieve\">http://e-maxx.ru/algo/eratosthenes_sieve</a>) So we can use this algo if we change it a little bit. Also, we will store results of calculation in array, e.g. <span class=\"tex-span\"><i>pre</i></span>. Namely, <span class=\"tex-span\"><i>pre</i>[<i>n</i>]</span> = <span class=\"tex-span\"><i>f</i>(<i>n</i>)</span>.</p><p>3) Now we can calculate partial sums of <span class=\"tex-span\"><i>pre</i></span> array. It can be made in a single pass just adding <span class=\"tex-span\"><i>pre</i>[<i>i</i> - 1]</span> to <span class=\"tex-span\"><i>pre</i>[<i>i</i>]</span>.</p><p>4) If we know partial sums of array then we can calculate sum of array elements between <span class=\"tex-span\"><i>l</i></span> and <span class=\"tex-span\"><i>r</i></span> in time proportional <span class=\"tex-span\"><i>O</i>(1)</span>, just calculate <span class=\"tex-span\"><i>pre</i>[<i>r</i>] - <i>pre</i>[<i>l</i> - 1]</span>.</p><p>5) Now we can read queries and immediately response to them. You shouldn't forget that right boundaries of intervals can be greater than <span class=\"tex-span\">10<sup class=\"upper-index\">7</sup></span>, so you can always decrease it to <span class=\"tex-span\">10<sup class=\"upper-index\">7</sup></span>, because all numbers in given list are less than <span class=\"tex-span\">10<sup class=\"upper-index\">7</sup></span>.</p><p><a href=\"/contest/385/problem/D\" title=\"Codeforces Round 226 (Div. 2)\">385D - Bear and Floodlight</a></p><p>In this task, it is crucial to understand that whether there is lighted part of road with length <span class=\"tex-span\"><i>dist</i></span> then next part should be lit in a such way that leftmost lighted point is touching with <span class=\"tex-span\"><i>dist</i></span>.</p><p>Let's suppose that road is lit from <span class=\"tex-span\"><i>l</i></span> to <span class=\"tex-span\"><i>d</i></span>. How we can find rightmost point on X axis that would be lit by next floodlight?</p><p>We can just use concepts of vector and rotation matrix.</p><p>Let's find vector <span class=\"tex-span\">(<i>dx</i>, <i>dy</i>)</span> from floodlight to point on X axis <span class=\"tex-span\">(<i>d</i>, 0)</span>. <span class=\"tex-span\">(<i>dx</i>, <i>dy</i>)</span> = <span class=\"tex-span\">(<i>d</i> - <i>x</i>, 0 - <i>y</i>)</span>.</p><p>Next point to rotate vector by <span class=\"tex-span\"><i>angle</i></span> degrees. We can use rotation matrix for this purpose.</p><p><span class=\"tex-span\">(<i>dx</i>, <i>dy</i>)</span> = <span class=\"tex-span\">(<i>dx</i>·<i>cos</i>(<i>angle</i>) - <i>dy</i>·<i>sin</i>(<i>angle</i>), <i>dx</i>·<i>sin</i>(<i>angle</i>) + <i>dy</i>·<i>cos</i>(<i>angle</i>))</span></p><p>Next, we should make second component <span class=\"tex-span\"><i>dy</i></span> of <span class=\"tex-span\">(<i>dx</i>, <i>dy</i>)</span> equal to <span class=\"tex-span\">1</span> by multiplying on coefficient <span class=\"tex-span\"><i>k</i></span>.</p><p>Now we can determine rightmost lighted point of X axis. It is <span class=\"tex-span\"><i>x</i> - <i>y</i>·<i>dx</i></span>.</p><p>You shouldn't forget that there is possibility for rightmost point to be infinitely far point.</p><p>From now on we can forget about geometry in this task.</p><p>Let's find fast way to determine optimal order of floodlights.</p><p>To achieve this goal, we can use dynamic programming approach. Namely, let's calculate answer for subsets of floodlights. Each subset would be represented as integer where <span class=\"tex-span\"><i>k</i></span> bit would be <span class=\"tex-span\">1</span> if <span class=\"tex-span\"><i>k</i></span> floodlight is presented in subset and <span class=\"tex-span\">0</span> if it is not, i.e. so named binary mask.</p><p>For example, <span class=\"tex-span\"><i>dp</i>[6]</span> — (<span class=\"tex-span\">6</span> — <span class=\"tex-span\">110<sub class=\"lower-index\">2</sub></span>) is optimal answer for subset from <span class=\"tex-span\">2</span> and <span class=\"tex-span\">3</span> floodlight.</p><p>Now, let's look through subsets <span class=\"tex-span\"><i>i</i></span> in <span class=\"tex-span\"><i>dp</i>[<i>i</i>]</span>. In subset <span class=\"tex-span\"><i>i</i></span> let's go through absent floodlights <span class=\"tex-span\"><i>j</i></span> and update result for subset where <span class=\"tex-span\"><i>j</i></span> floodlight is present, i.e. dp[ <span class=\"tex-span\"><i>i</i></span> or <span class=\"tex-span\">2<sup class=\"upper-index\"><i>j</i></sup></span> ] = max(dp[ <span class=\"tex-span\"><i>i</i></span> or <span class=\"tex-span\">2<sup class=\"upper-index\"><i>j</i></sup></span>], dp[ <span class=\"tex-span\"><i>i</i></span> ] + calc_rightmost_lighted_point() ). As we can calculate rightmost lighted point, so updating of answer shouldn't be a problem.</p><p><a href=\"/contest/385/problem/E\" title=\"Codeforces Round 226 (Div. 2)\">385E - Bear in the Field</a></p><p>In this task there are several problems that should be concerned:</p><p>1) Simple modeling of bear movement would cause TLE due to <span class=\"tex-span\"><i>t</i></span> <span class=\"tex-span\"> ≤ </span> <span class=\"tex-span\">10<sup class=\"upper-index\">18</sup></span>.</p><p>2) Task can't be solved by separating <span class=\"tex-span\"><i>x</i></span> and <span class=\"tex-span\"><i>y</i></span> axes because <span class=\"tex-span\"><i>x</i></span> and <span class=\"tex-span\"><i>y</i></span> depends on each other.</p><p>3) Also, we can't use standart method of cycle finding via modeling for a short time and checking on collisions because coordinates limitations are very large.</p><p>Let's say we have matrix <span class=\"tex-span\">(<i>x</i><sub class=\"lower-index\"><i>i</i></sub>, <i>y</i><sub class=\"lower-index\"><i>i</i></sub>, <i>dx</i><sub class=\"lower-index\"><i>i</i></sub>, <i>dy</i><sub class=\"lower-index\"><i>i</i></sub>, <i>t</i><sub class=\"lower-index\"><i>i</i></sub>, 1)</span>.</p><p>If we multiply previous matrix by following matrix long long base[6][6] = {</p><p>{2,1,1,1,0,0},</p><p>{1,2,1,1,0,0},</p><p>{1,0,1,0,0,0},</p><p>{0,1,0,1,0,0},</p><p>{0,0,1,1,1,0},</p><p>{0,0,2,2,1,1} };</p><p>we will have get parameters on next step.</p><p>Where did the matrix? Let us write out how to change parameters with each step and see the similarity matrix.</p><p><span class=\"tex-span\"><i>x</i></span> = <span class=\"tex-span\">2·<i>x</i></span> + <span class=\"tex-span\">1·<i>y</i></span> + <span class=\"tex-span\">1·<i>dx</i></span> + <span class=\"tex-span\">0·<i>dy</i></span> + <span class=\"tex-span\">0·<i>t</i></span> + <span class=\"tex-span\">0·1</span>.</p><p><span class=\"tex-span\"><i>y</i></span> = <span class=\"tex-span\">1·<i>x</i></span> + <span class=\"tex-span\">2·<i>y</i></span> + <span class=\"tex-span\">0·<i>dx</i></span> + <span class=\"tex-span\">1·<i>dy</i></span> + <span class=\"tex-span\">0·<i>t</i></span> + <span class=\"tex-span\">0·1</span>.</p><p><span class=\"tex-span\"><i>dx</i></span> = <span class=\"tex-span\">1·<i>x</i></span> + <span class=\"tex-span\">1·<i>y</i></span> + <span class=\"tex-span\">1·<i>dx</i></span> + <span class=\"tex-span\">0·<i>dy</i></span> + <span class=\"tex-span\">1·<i>t</i></span> + <span class=\"tex-span\">2·1</span>.</p><p><span class=\"tex-span\"><i>dy</i></span> = <span class=\"tex-span\">1·<i>x</i></span> + <span class=\"tex-span\">1·<i>y</i></span> + <span class=\"tex-span\">0·<i>dx</i></span> + <span class=\"tex-span\">1·<i>dy</i></span> + <span class=\"tex-span\">1·<i>t</i></span> + <span class=\"tex-span\">2·1</span>.</p><p><span class=\"tex-span\"><i>t</i></span> = <span class=\"tex-span\">0·<i>x</i></span> + <span class=\"tex-span\">0·<i>y</i></span> + <span class=\"tex-span\">0·<i>dx</i></span> + <span class=\"tex-span\">0·<i>dy</i></span> + <span class=\"tex-span\">1·<i>t</i></span> + <span class=\"tex-span\">1·1</span>.</p><p><span class=\"tex-span\">1</span> = <span class=\"tex-span\">0·<i>x</i></span> + <span class=\"tex-span\">0·<i>y</i></span> + <span class=\"tex-span\">0·<i>dx</i></span> + <span class=\"tex-span\">0·<i>dy</i></span> + <span class=\"tex-span\">0·<i>t</i></span> + <span class=\"tex-span\">1·1</span>.</p><p>So if we calculate <span class=\"tex-span\"><i>t</i> - 1</span> power of <span class=\"tex-span\"><i>base</i></span> and then multiply <span class=\"tex-span\">(<i>sx</i>, <i>sy</i>, <i>dx</i>, <i>dy</i>, <i>t</i>, 1)</span> by it we will calculate parameters at moment <span class=\"tex-span\"><i>t</i></span>.</p><p>Power of matrix can be calculated via binary power modulo algo due to associativity of matrix multiplication. More info at <a href=\"http://e-maxx.ru/algo/binary_pow\">http://e-maxx.ru/algo/binary_pow</a></p><p>Using trivial matrix multiplication algo we will solve this task in time proportional <span class=\"tex-span\">6<sup class=\"upper-index\">3</sup>·<i>log</i>(<i>t</i>)</span>.</p></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/385\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 226 (Div. 2)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-2930-10569\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"2930\",\n blogEntryId: \"10514\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-10569\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+85</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-10569\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/CleRIC\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/CleRIC\">\n CleRIC\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Jan/23/2014 19:33\">10 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/10514#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/10514#comments\">\n 30\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"10585\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (25)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158988\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/OpalDshawn\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/40047/avatar/c26edf07c13c133a.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/OpalDshawn\" title=\"Master OpalDshawn\" class=\"rated-user user-orange\">OpalDshawn</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2014 22:59\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158988\" href=\"?#comment-158988\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"158988\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"158988\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"40047\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158988\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Great Editorial!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158988 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158988 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158988\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159026\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Xellos\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/69675/avatar/8526bcfc8e687b43.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/Xellos\" title=\"International Grandmaster Xellos\" class=\"rated-user user-red\">Xellos</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/25/2014 02:06\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159026\" href=\"?#comment-159026\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"159026\" revisionCount=\"7\" revision=\"7\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">7</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"159026\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"28\"\r\n data-commentUserId=\"69675\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+28</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159026\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I solved E (theoretically, I don't really want to implement it) by solving the system of equations:</p> <center><span class=\"tex-span\"><i>x</i>(<i>t</i>) = [<i>x</i>(<i>t</i> - 1) + <i>v</i><sub class=\"lower-index\"><i>x</i></sub>(<i>t</i>) - 1]%<i>N</i> + 1</span></center> <center><span class=\"tex-span\"><i>y</i>(<i>t</i>) = [<i>y</i>(<i>t</i> - 1) + <i>v</i><sub class=\"lower-index\"><i>y</i></sub>(<i>t</i>) - 1]%<i>N</i> + 1</span></center> <center><span class=\"tex-span\"><i>v</i><sub class=\"lower-index\"><i>x</i></sub>(<i>t</i>) = <i>v</i><sub class=\"lower-index\"><i>x</i></sub>(<i>t</i> - 1) + <i>t</i> - 1 + <i>x</i>(<i>t</i> - 1) + <i>y</i>(<i>t</i> - 1)</span></center> <center><span class=\"tex-span\"><i>v</i><sub class=\"lower-index\"><i>y</i></sub>(<i>t</i>) = <i>v</i><sub class=\"lower-index\"><i>y</i></sub>(<i>t</i> - 1) + <i>t</i> - 1 + <i>x</i>(<i>t</i> - 1) + <i>y</i>(<i>t</i> - 1)</span></center><p>for $t > 0$, where the values of <span class=\"tex-span\">(<i>x</i>, <i>y</i>, <i>v</i><sub class=\"lower-index\"><i>x</i></sub>, <i>v</i><sub class=\"lower-index\"><i>y</i></sub>)(0)</span> are given as input parameters, and the time is 0-based.</p><p>Firstly, we want to get rid of the modulo function. We can't just compute all variables modulo <span class=\"tex-span\"><i>N</i></span>, because there's the -1, so we'll shift the coordinates to <span class=\"tex-span\">(<i>x</i>', <i>y</i>')(<i>t</i>)</span>, where <span class=\"tex-span\"><i>x</i>' = <i>x</i> - 1</span>, <span class=\"tex-span\"><i>y</i>' = <i>y</i> - 1</span>. Now the equations become</p> <center><span class=\"tex-span\"><i>x</i>'(<i>t</i>) = <i>x</i>'(<i>t</i> - 1) + <i>v</i><sub class=\"lower-index\"><i>x</i></sub>(<i>t</i>)</span></center> <center><span class=\"tex-span\"><i>y</i>'(<i>t</i>) = <i>y</i>'(<i>t</i> - 1) + <i>v</i><sub class=\"lower-index\"><i>y</i></sub>(<i>t</i>)</span></center> <center><span class=\"tex-span\"><i>v</i><sub class=\"lower-index\"><i>x</i></sub>(<i>t</i>) = <i>v</i><sub class=\"lower-index\"><i>x</i></sub>(<i>t</i> - 1) + <i>t</i> + 1 + <i>x</i>'(<i>t</i> - 1) + <i>y</i>'(<i>t</i> - 1)</span></center> <center><span class=\"tex-span\"><i>v</i><sub class=\"lower-index\"><i>y</i></sub>(<i>t</i>) = <i>v</i><sub class=\"lower-index\"><i>y</i></sub>(<i>t</i> - 1) + <i>t</i> + 1 + <i>x</i>'(<i>t</i> - 1) + <i>y</i>'(<i>t</i> - 1)</span></center><p>where all variables are computed modulo $N$ (we'll omit that from now on). We can compute <span class=\"tex-span\">(<i>x</i>, <i>y</i>, <i>v</i><sub class=\"lower-index\"><i>x</i></sub>, <i>v</i><sub class=\"lower-index\"><i>y</i></sub>)(1)</span> from this, and further substitute for <span class=\"tex-span\"><i>v</i><sub class=\"lower-index\"><i>x</i></sub>, <i>v</i><sub class=\"lower-index\"><i>y</i></sub></span>, which gives for <span class=\"tex-span\"><i>t</i> > 1</span></p> <center><span class=\"tex-span\"><i>x</i>'(<i>t</i>) - <i>x</i>'(<i>t</i> - 1) = <i>x</i>'(<i>t</i> - 1) - <i>x</i>'(<i>t</i> - 2) + <i>t</i> + 1 + <i>x</i>'(<i>t</i> - 1) + <i>y</i>'(<i>t</i> - 1)</span></center> <center><span class=\"tex-span\"><i>y</i>'(<i>t</i>) - <i>y</i>'(<i>t</i> - 1) = <i>y</i>'(<i>t</i> - 1) - <i>y</i>'(<i>t</i> - 2) + <i>t</i> + 1 + <i>x</i>'(<i>t</i> - 1) + <i>y</i>'(<i>t</i> - 1)</span></center><p>Let's now define</p> <center><span class=\"tex-span\"><i>s</i>(<i>t</i>) = <i>x</i>'(<i>t</i>) + <i>y</i>'(<i>t</i>)</span></center> <center><span class=\"tex-span\"><i>d</i>(<i>t</i>) = <i>x</i>'(<i>t</i>) - <i>y</i>'(<i>t</i>)</span></center><p>using which we can rewrite the sum and difference of the equations above to</p> <center><span class=\"tex-span\"><i>d</i>(<i>t</i>) - <i>d</i>(<i>t</i> - 1) = <i>d</i>(<i>t</i> - 1) - <i>d</i>(<i>t</i> - 2)</span></center> <center><span class=\"tex-span\"><i>s</i>(<i>t</i>) - <i>s</i>(<i>t</i> - 1) = <i>s</i>(<i>t</i> - 1) - <i>s</i>(<i>t</i> - 2) + 2(<i>t</i> + 1) + 2<i>s</i>(<i>t</i> - 1)</span></center><p>Once again, we define $q(t)=s(t)+t+2$ (actually, it's <span class=\"tex-span\"><i>s</i>(<i>t</i>) + <i>t</i> + <i>c</i></span>, and we compute the constant <span class=\"tex-span\"><i>c</i></span> by substituting and trying to get the constant term to 0), and rewrite our equations to</p> <center><span class=\"tex-span\"><i>d</i>(<i>t</i>) = 2<i>d</i>(<i>t</i> - 1) - <i>d</i>(<i>t</i> - 2)</span></center> <center><span class=\"tex-span\"><i>q</i>(<i>t</i>) = 4<i>q</i>(<i>t</i> - 1) - <i>q</i>(<i>t</i> - 2)</span></center><p>which can be solved explicitly (I'm lazy, so I'm just using Wolfram Alpha, read more about linear recurrent equations on Wikipedia or something):</p> <center><img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/5ec2a1c8cb9dd5c6d22e9c89f85ea721c45a9659.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></center> <center><span class=\"tex-span\"><i>d</i>(<i>t</i>) = <i>C</i> * <i>t</i> + <i>D</i></span></center><p>where the parameters $A..D$ are given by the values for <span class=\"tex-span\"><i>t</i> ≤ 1</span>.</p><p>This is more of a theoretical solution (since as long as we get the recurrences for <span class=\"tex-span\"><i>d</i>(<i>t</i>)</span> and <span class=\"tex-span\"><i>q</i>(<i>t</i>)</span>, it's best to use matrix multiplication), but I just wanted to do it this way :D</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159026 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159026 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159026\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159027\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/bilalyasar\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/88216/avatar/25c063de47c0f66a.jpg'/> </a>\n <div><a href=\"/profile/bilalyasar\" title=\"Expert bilalyasar\" class=\"rated-user user-blue\">bilalyasar</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/25/2014 03:59\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159027\" href=\"?#comment-159027\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"159027\" revisionCount=\"23\" revision=\"23\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">23</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"159027\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"88216\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159027\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>i think the matrix should be that: {2,1,1,1,0,0},</p><p>{1,2,1,1,0,0},</p><p>{1,0,1,0,0,0},</p><p>{0,1,0,1,0,0},</p><p>{0,0,1,1,1,0},</p><p>{0,0,0,0,1,1} };</p><p>i tried and solved it. with this matrix.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159027 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159027 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159027\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159144\" commentParentId=\"159027\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Amir.bh\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/29435/avatar/84331c66da301d6d.jpg'/> </a>\n <div><a href=\"/profile/Amir.bh\" title=\"Candidate Master Amir.bh\" class=\"rated-user user-violet\">Amir.bh</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/26/2014 15:32\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159144\" href=\"?#comment-159144\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159027\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159144\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"29435\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159144\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Rev. 23????! How could this happen?! :D</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159144 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159144 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159144\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159162\" commentParentId=\"159144\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Xellos\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/69675/avatar/8526bcfc8e687b43.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/Xellos\" title=\"International Grandmaster Xellos\" class=\"rated-user user-red\">Xellos</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/26/2014 17:13\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159162\" href=\"?#comment-159162\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159144\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159162\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"69675\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159162\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Maybe for the same reason as rev.7 of my comment above — I edit my comment, click "Save", nothing happens; I wait until my internet connection is stronger, click again, and nothing happens again, etc., until I lose patience and reload the page. And look what happened: the revisions were counted, but my comment wasn't edited. Some bug of CF, maybe.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159162 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159162 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159162\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159054\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/llaki\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/24382/avatar/6683eebf7eea08ec.jpg'/> </a>\n <div><a href=\"/profile/llaki\" title=\"Expert llaki\" class=\"rated-user user-blue\">llaki</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/25/2014 15:18\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159054\" href=\"?#comment-159054\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159054\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"24382\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159054\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Nice editorial. Anyways, I had a sense that explanation of problem E does not give you an idea of how you can come up with that solution. Let me clarify that: The state can be described by following variables: x — where is the bear currently (x-coordinate); y — where is the bear currently (y-coordinate); dx — the current speed towards X axis; dy — the current speed towards Y axis; t — time passed after the start;</p><p>This information is enough to describe a state. Now let's see how the state changes: (dx)' = dx + (x+y+t), (dy)' = dy+(x+y+t), (x)' = x + (dx)' = 2x+y+dx+t, (y)'=x+2y+dy+t, (t)'= t+1.</p><p>As we see, the new state is similar to linear combination of previous state components, except for t=t+1 (1 is not in a state). It is very similar to matrix multiplication, except for we don't have 1. So we can make a matrix this way: Let's say the state is (1x6) matrix : (x, y, dx, dy, t, 1) and the matrix (M) is 100001 021110 012110 010100 001010 011111 It's easy to see why the new state is the old state matrix multiplied by M. The rest is easy, our final state is going to be the initial state matrix multiplied by the T-th power of M. Of course we're gonna use the fast exponentiation. (The naive multiplication is fine here, because the sizes are too small)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159054 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159054 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159054\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159061\" commentParentId=\"159054\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/KKpoker\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/120167/avatar/297c9d6f6c6672be.jpg'/> </a>\n <div><a href=\"/profile/KKpoker\" title=\"Specialist KKpoker\" class=\"rated-user user-cyan\">KKpoker</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/25/2014 16:34\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159061\" href=\"?#comment-159061\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159054\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"159061\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"159061\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"4\"\r\n data-commentUserId=\"120167\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+4</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159061\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>thx a lot ~ during the exam i think the raspberry will be eaten all , then the number will change from x+y-->1 a silly misunderstanding T_T</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159061 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159061 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159061\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"372356\" commentParentId=\"159054\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/nguyenit67\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/509284/avatar/98668c3aa6c04ca6.jpg'/> </a>\n <div><a href=\"/profile/nguyenit67\" title=\"Pupil nguyenit67\" class=\"rated-user user-green\">nguyenit67</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/11/2017 14:02\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-372356\" href=\"?#comment-372356\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159054\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"372356\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"509284\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-372356\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I'm sorry :) but I don't see why (x)'= x+(dx)'? Could u explain that to me?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-372356 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-372356 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-372356\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"372645\" commentParentId=\"372356\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/nguyenit67\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/509284/avatar/98668c3aa6c04ca6.jpg'/> </a>\n <div><a href=\"/profile/nguyenit67\" title=\"Pupil nguyenit67\" class=\"rated-user user-green\">nguyenit67</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/12/2017 08:25\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-372645\" href=\"?#comment-372645\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-372356\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"372645\" revisionCount=\"4\" revision=\"4\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">4</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"372645\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"509284\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-372645\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Ah</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-372645 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-372645 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-372645\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"372646\" commentParentId=\"159054\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/nguyenit67\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/509284/avatar/98668c3aa6c04ca6.jpg'/> </a>\n <div><a href=\"/profile/nguyenit67\" title=\"Pupil nguyenit67\" class=\"rated-user user-green\">nguyenit67</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/12/2017 08:26\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-372646\" href=\"?#comment-372646\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159054\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"372646\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"509284\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-372646\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Ah now I see it. Thank you for your explanation :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-372646 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-372646 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-372646\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159079\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/MoustafaMaher\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/47658/avatar/48ad52ec2bf89c75.jpg'/> </a>\n <div><a href=\"/profile/MoustafaMaher\" title=\"Candidate Master MoustafaMaher\" class=\"rated-user user-violet\">MoustafaMaher</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/25/2014 19:18\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159079\" href=\"?#comment-159079\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159079\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"47658\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159079\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Problem D !?! </p><p>how u can calculate calc_rightmost_lighted_point() in ur Dp without keeping the last right_most_point u can get till before this state </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159079 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159079 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159079\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159093\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Lord_F\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/41018/avatar/1e2b817ca83c107e.jpg'/> </a>\n <div><a href=\"/profile/Lord_F\" title=\"Candidate Master Lord_F\" class=\"rated-user user-violet\">Lord_F</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/25/2014 21:37\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159093\" href=\"?#comment-159093\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"159093\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"159093\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"41018\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159093\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>By the way, in problem D you can use law of sines to find the distance that is lighted with some floodlight.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159093 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159093 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159093\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159105\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/-emli-\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/29285/avatar/9fa3a36fa8f9d060.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/-emli-\" title=\"Pupil -emli-\" class=\"rated-user user-green\">-emli-</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/25/2014 23:59\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159105\" href=\"?#comment-159105\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159105\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"29285\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159105\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In problem C , i can't understand why we add pre[i-1] to pre[i]?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159105 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159105 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159105\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159109\" commentParentId=\"159105\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/piotreekw\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/piotreekw\" title=\"Specialist piotreekw\" class=\"rated-user user-cyan\">piotreekw</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/26/2014 00:51\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159109\" href=\"?#comment-159109\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159105\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159109\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"151924\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159109\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>If you iterate i from 2 to n-1 adding pre[i-1] to pre[i], every new pre[i] will contain sum of all pre from 1 to i</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159109 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159109 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159109\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159126\" commentParentId=\"159109\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/-emli-\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/29285/avatar/9fa3a36fa8f9d060.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/-emli-\" title=\"Pupil -emli-\" class=\"rated-user user-green\">-emli-</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/26/2014 09:24\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159126\" href=\"?#comment-159126\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159109\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159126\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"29285\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159126\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thank you! one more question how to prove that pre[r]-pre[l-1] is answer of query?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159126 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159126 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159126\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159129\" commentParentId=\"159126\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ReekinAcer\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/ReekinAcer\" title=\"Expert ReekinAcer\" class=\"rated-user user-blue\">ReekinAcer</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/26/2014 12:01\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159129\" href=\"?#comment-159129\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159126\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159129\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"106426\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159129\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I think it is clearer if we denote Cnt[i] = f(i) and Sum[i] = Cnt[1] + Cnt[2] + ... + Cnt[i]. Now, the answer for a query on [l, r] is Sum[r]-Sum[l-1].</p><p>Sum[r]-Sum[l-1] = (Cnt[1] + Cnt[2] + ... + Cnt[r])-(Cnt[1] + Cnt[2] + ... + Cnt[l-1]) = [(Cnt[1] + ... + Cnt[l-1]) + (Cnt[l] + Cnt[l + 1] + ... + Cnt[r])] — (Cnt[1] + ... + Cnt[l-1]) = Cnt[l] + Cnt[l + 1] + ... + Cnt[r].</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159129 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159129 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159129\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"211346\" commentParentId=\"159105\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/G_Hani\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/119692/avatar/ea9b44051a710c1b.jpg'/> </a>\n <div><a href=\"/profile/G_Hani\" title=\"Specialist G_Hani\" class=\"rated-user user-cyan\">G_Hani</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/06/2015 00:49\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-211346\" href=\"?#comment-211346\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159105\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"211346\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"119692\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-211346\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p><a class=\"rated-user user-green\" href=\"/profile/-emli-\" title=\"Pupil -emli-\">-emli-</a> <a class=\"rated-user user-blue\" href=\"/profile/ReekinAcer\" title=\"Expert ReekinAcer\">ReekinAcer</a> can u help me please. here my code for C and get WA at tc 4 !! <a href=\"/contest/385/submission/9731769\" title=\"Submission 9731769 by G_Hani\">9731769</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-211346 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-211346 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-211346\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159138\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/shubh09\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/shubh09\" title=\"Expert shubh09\" class=\"rated-user user-blue\">shubh09</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/26/2014 13:36\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159138\" href=\"?#comment-159138\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159138\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"72364\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159138\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Nice editorial! But I suppose that a link to a solution implementing the idea outlined in the editorial for every question would help us understand them even better!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159138 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159138 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159138\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159141\" commentParentId=\"159138\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Lord_F\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/41018/avatar/1e2b817ca83c107e.jpg'/> </a>\n <div><a href=\"/profile/Lord_F\" title=\"Candidate Master Lord_F\" class=\"rated-user user-violet\">Lord_F</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/26/2014 14:13\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159141\" href=\"?#comment-159141\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159138\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"159141\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"159141\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"41018\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159141\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Well, you can use "Status filter"</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159141 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159141 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159141\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159178\" commentParentId=\"159141\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/shubh09\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/shubh09\" title=\"Expert shubh09\" class=\"rated-user user-blue\">shubh09</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/26/2014 18:14\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159178\" href=\"?#comment-159178\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159141\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159178\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"72364\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159178\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Well, not all the accepted solutions use the idea mentioned in the editorials. It's a bit inconvenient browsing through all accepted solutions to find the one which does.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159178 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159178 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159178\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"330629\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/adityagupta1089\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/337877/avatar/e2156094910d501.jpg'/> </a>\n <div><a href=\"/profile/adityagupta1089\" title=\"Expert adityagupta1089\" class=\"rated-user user-blue\">adityagupta1089</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Dec/14/2016 22:58\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-330629\" href=\"?#comment-330629\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"330629\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"330629\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"337877\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-330629\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In problem C, I did made a cnt array (or say a hashmap) and did find all primes below the maximum x using Sieve of Erathosthenes, then for each prime I iterated over every number and and found f(p) and stored them in a Binary Index Tree, but that didn't help. I believe my complexity is O(n(logn)(loglogn)+m(logn+logP)+PlogP) where P(664,579~10^7) is the count of primes below maximum x so total operations are around 5e6+6e7+4e7 but it has a TLE?.<a href=\"//codeforces.com/contest/385/submission/22981801\">This</a> is my submission.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-330629 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-330629 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-330629\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"587392\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/reet_bhaati\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1176149/avatar/7f68facc9bda856e.jpg'/> </a>\n <div><a href=\"/profile/reet_bhaati\" title=\"Specialist reet_bhaati\" class=\"rated-user user-cyan\">reet_bhaati</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/10/2020 10:46\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-587392\" href=\"?#comment-587392\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"587392\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"-8\"\r\n data-commentUserId=\"1176149\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-587392\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>can anyone help me out? I have tried 385C and it gives me a runtime error on test case 4 link to my code — <a href=\"https://ideone.com/fork/GMagWh\">https://ideone.com/fork/GMagWh</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-587392 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-587392 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-587392\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"642670\" commentParentId=\"587392\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/back_to_code\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1292092/avatar/b57b403a9af2ef26.jpg'/> </a>\n <div><a href=\"/profile/back_to_code\" title=\"Specialist back_to_code\" class=\"rated-user user-cyan\">back_to_code</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/15/2020 21:38\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-642670\" href=\"?#comment-642670\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-587392\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"642670\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"642670\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1292092\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-642670\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I don't know if you are still looking for this :</p><p>That might be because x or y i.e the query ranges might be going out of limits. Also it may help the others who attempt it.</p><p>Edit : Also if anyone is getting TLE even after implementing same approach use:</p> <pre><code>ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);\n</code></pre></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-642670 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-642670 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-642670\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"658423\" commentParentId=\"587392\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/apoorva222g\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1213778/avatar/2153e9cce1fd37f.jpg'/> </a>\n <div><a href=\"/profile/apoorva222g\" title=\"Expert apoorva222g\" class=\"rated-user user-blue\">apoorva222g</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/09/2020 11:58\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-658423\" href=\"?#comment-658423\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-587392\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"658423\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1213778\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-658423\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Reduce any l or r to 10^7 if it is greater than 10^7. Try this case 1 2000 1 1424767024 1629755604</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-658423 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-658423 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-658423\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"686007\" commentParentId=\"658423\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/y0g38h_kum4r\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1561883/avatar/5594dfbdb87a226d.jpg'/> </a>\n <div><a href=\"/profile/y0g38h_kum4r\" title=\"Expert y0g38h_kum4r\" class=\"rated-user user-blue\">y0g38h_kum4r</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/25/2020 02:40\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-686007\" href=\"?#comment-686007\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-658423\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"686007\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1561883\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-686007\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>OH! thanks a lot for this test case!!!!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-686007 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-686007 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-686007\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n <br/>\r\n\r\n<div id=\"editBox-10585\" style=\"width:50em;display:none;\">\r\n <div class=\"previewBody\" style=\"border: 1px solid #d4d4d4; margin-bottom: 0.5em; padding: 0.25em; display:none;\"> </div>\r\n <div style=\"width: 1px\"> </div>\r\n <div class=\"commentLocale\" style=\"position: relative; top: 0.5em;left:4px;display: none;\">\r\n <input type=\"radio\" name=\"locale\" value=\"en\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In English</span>\r\n <input style=\"margin-left:1em\" type=\"radio\" name=\"locale\" value=\"ru\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In Russian</span>\r\n </div>\r\n <textarea data-drafts-id=\"CommentReplyFrame\" class=\"wysiwyg\" name=\"editContent\" rows=\"20\" style=\"width:99%;\"></textarea>\r\n <div class=\"error error__content\"></div>\r\n <div style=\"text-align:center;\">\r\n <input type=\"button\" name=\"preview\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Preview\"/>\r\n <input type=\"button\" name=\"save\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Save\"/>\r\n </div>\r\n</div>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n\r\nvar firstPreview10585 = true;\r\nvar lastPreviewContent10585 = '';\r\n\r\nif (!window.moveCommentRevision) {\r\n moveCommentRevision = function(e, dir) {\r\n var p = e.parent();\r\n var revisionCount = parseInt(p.attr(\"revisionCount\"));\r\n var revision = parseInt(p.attr(\"revision\"));\r\n var next = revision + dir;\r\n var commentId = p.attr(\"commentId\");\r\n if (next >= 1 && next <= revisionCount) {\r\n $.post(\r\n \"/data/comment-data\",\r\n {action: \"revision\", commentId: commentId, revision: next},\r\n function(json) {\r\n if (json.success == \"true\") {\r\n var parentDiv = e;\r\n\r\n while (parentDiv !== null && (parentDiv[0].nodeName.toLowerCase() !== \"td\" || !parentDiv.hasClass(\"right\"))) {\r\n parentDiv = parentDiv.parent();\r\n }\r\n\r\n if (parentDiv === null) {\r\n return;\r\n }\r\n\r\n parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\").html(json.content);\r\n Codeforces.setupSpoilers(parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\"));\r\n p.attr(\"revision\", next);\r\n p.find(\"span.revision\").text(next);\r\n if (next == 1) {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"visible\");\r\n }\r\n if (next == revisionCount) {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"visible\");\r\n }\r\n\r\n window.updateTypography();\r\n MathJax.Hub.Typeset();\r\n } else {\r\n alert(e.error);\r\n }\r\n },\r\n \"json\"\r\n );\r\n }\r\n };\r\n}\r\n\r\n$(\"div[commentableId=10585] a.leftRevision\").click(function () {\r\n window.moveCommentRevision($(this), -1);\r\n return false;\r\n});\r\n\r\n$(\"div[commentableId=10585] a.rightRevision\").click(function () {\r\n window.moveCommentRevision($(this), +1);\r\n return false;\r\n});\r\n\r\n\r\n\r\n });\n </script>\n\r\n\r\n <script src=\"//codeforces.org/s/81027/js/swfobject-2.2.min.js\" type=\"text/javascript\"></script>\n <script src=\"//codeforces.org/s/81027/js/ftaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n if (window.evercookie) {\n var ec = new evercookie({\n history: false,\n silverlight: false,\n baseurl: '',\n asseturi: '/assets',\n phpuri: '/2fdcd78',\n pngPath: '/eps',\n etagPath: '/ees',\n cachePath: '/ecs'\n });\n\n var randomNumber = function () {\n return Math.random().toString(36).substr(2);\n };\n\n var randomToken = function () {\n return (randomNumber() + randomNumber()).substring(0, 18);\n };\n\n window._ftaa = \"\";\n\n ec.get(\"70a7c28f3de\", function (value) {\n window._ftaa = value;\n if (!window._ftaa) {\n window._ftaa = randomToken();\n ec.set(\"70a7c28f3de\", window._ftaa);\n }\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n } else {\n window._ftaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\n <script src=\"//codeforces.org/s/81027/js/bfaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n var fpCallback = function() {\n Fingerprint2.get({}, function(components) {\n window._bfaa = Fingerprint2.x64hash128(components.map(function (pair) { return pair.value }).join(), 31);\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n };\n if (typeof Fingerprint2 !== 'undefined') {\n if (window.requestIdleCallback) {\n requestIdleCallback(fpCallback)\n } else {\n setTimeout(fpCallback, 500)\n }\n } else {\n window._bfaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"a.new-root-comment\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n\r\n $(\".comment-table .reply a\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".vote-for-comment\").mouseover(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").mouseout(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").click(function () {\r\n var vote = $(this);\r\n var commentId = $(this).parent().attr(\"commentid\");\r\n var commentRating = $(this).parent().attr(\"data-commentRating\");\r\n var direction = $(this).attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n $.post(\"/data/comment/vote\", {commentId: commentId, _tta: Codeforces.tta(), vote: direction, commentRating: commentRating}, function(data) {\r\n if (direction != 0 && !ownComment && data[\"success\"] == \"true\") {\r\n vote.parent().find(\".vote-for-comment\").attr(\"voteDirection\", 0);\r\n if (direction == 1)\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n else {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.closest(\".CommentVoteFrame\").find(\".ComplaintFrame\").css(\"display\", \"inline-block\");\r\n }\r\n vote.find(\"img\").attr(\"popacity\", \"1.0\");\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n vote.parent().find(\".commentRating\").html(data[\"commentRating\"]);\r\n }\r\n Codeforces.showMessage(data[\"message\"]);\r\n }, \"json\");\r\n return false;\r\n });\r\n\r\n $(\".negative-comment-vote\").closest(\".comment-table\").addClass(\"comment-bad\");\r\n\r\n $(\".troll-comment-vote\").closest(\".comment\").css(\"display\", \"none\");\r\n\r\n $(\".too-negative-comment-vote\").closest(\".comment-table\").each(function () {\r\n var e = $(this);\r\n e.addClass(\"comment-too-bad\");\r\n var commentId = e.attr(\"commentId\");\r\n $(\"<div class='bad-comment-replacement ttypography'>The comment is hidden because of too negative feedback, click <a href=# class=show-bad-comment-link>here</a> to view it</div>\").appendTo(\r\n e.find(\".right\")\r\n );\r\n e.find(\".comment-content\").hide();\r\n e.find(\".show-bad-comment-link\").click(function () {\r\n e.find(\".comment-content\").show();\r\n e.find(\".bad-comment-replacement\").hide();\r\n return false;\r\n });\r\n });\r\n });\n </script>\n </div>\r\n\r\n <style type=\"text/css\">\r\n .new-comments-box {\r\n padding: 0.5em;\r\n width: 22px;\r\n font-size: 1.3rem;\r\n font-weight: bold !important;\r\n\r\n position: fixed;\r\n top: 40%;\r\n right: 0;\r\n opacity: 0.2;\r\n color: white;\r\n text-align: center;\r\n\r\n border: 1px solid #222;\r\n background-color: #888 !important;\r\n border-radius: 3px;\r\n -moz-border-radius: 3px;\r\n -webkit-border-radius: 3px;\r\n }\r\n\r\n .new-comments-box:hover {\r\n opacity: 1;\r\n }\r\n\r\n .new-comments-box .dir:hover {\r\n background: #3B5998 !important;\r\n cursor: pointer;\r\n }\r\n </style>\r\n\r\n <div class=\"new-comments-box\" data-position=\"outside\" data-index=\"-1\" style=\"display: none;\">\r\n <div class=\"up dir\" title=\"Ctrl+Up\">↑<hr/>\r\n </div>\r\n <div class=\"info\" title=\"New comments\"></div>\r\n <div class=\"down dir\" title=\"Ctrl+Down\">\r\n <hr/>↓\r\n </div>\r\n </div>\r\n\r\n <script>\r\n $(\".show-archived-checkbox\").change(function () {\r\n const checked = $(this).is(\":checked\");\r\n $.post(\"/data/comment-data\", {action: \"setShowArchived\", checked}, function (json) {\r\n if (json[\"success\"] !== \"true\") {\r\n alert(json[\"error\"]);\r\n } else {\r\n if (checked) {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are now displayed\")\r\n } else {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are no longer displayed\")\r\n }\r\n }\r\n });\r\n return false;\r\n });\r\n\r\n function gotoComment(direction) {\r\n var box = $(\".new-comments-box\");\r\n var index = parseInt(box.attr(\"data-index\"));\r\n if (index == -1)\r\n index = 0;\r\n else\r\n index = Math.max(0, Math.min(parseInt(box.find(\".info\").text()) - 1, index + direction));\r\n box.attr(\"data-index\", index);\r\n var comment = $($(\".comment .highlight-blue[commentId]\").get(index));\r\n $('html, body').animate({\r\n 'scrollTop': Math.max(0, comment.offset().top - ($(window).height() - comment.height()) / 2)\r\n });\r\n return false;\r\n }\r\n\r\n $(\".new-comments-box .down\").click(function () {\r\n return gotoComment(1);\r\n });\r\n\r\n $(\".new-comments-box .up\").click(function () {\r\n return gotoComment(-1);\r\n });\r\n\r\n $(document).keydown(function (e) {\r\n var code = (e.keyCode ? e.keyCode : e.which);\r\n if (e.ctrlKey) {\r\n if (code == 38 || code == 40) {\r\n gotoComment(code - 39);\r\n }\r\n }\r\n });\r\n\r\n var newCommentCount = $(\".comment .highlight-blue[commentId]\").length;\r\n if (newCommentCount > 0) {\r\n $(\".new-comments-box .info\").text(newCommentCount);\r\n $(\".new-comments-box\").show();\r\n }\r\n\r\n $('table.comment-table').mouseenter(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").addClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n\r\n $('table.comment-table').mouseleave(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").removeClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n </script>\r\n\r\n\r\n\r\n <script>\r\n function adjustTopicComplainFrames() {\r\n let topicIds = [];\r\n\r\n $(\".has-topic-id\").each(function () {\r\n const $this = $(this);\r\n const topicId = $this.attr(\"topicId\");\r\n if (topicId) {\r\n topicIds.push(topicId);\r\n }\r\n });\r\n\r\n $.post(\"/data/topics\", {\r\n action: \"findComplainableTopicIds\",\r\n topicIds: topicIds.join(\",\")\r\n }, function (json) {\r\n if (json[\"success\"] === \"true\") {\r\n for (const topicId of json[\"complainableTopicIds\"].split(\",\")) {\r\n $(\".has-topic-id[topicId=\" + topicId + \"]\").each(function () {\r\n $(this).find(\".meta .ComplaintFrame\").css(\"display\", \"inline-block\");\r\n });\r\n }\r\n }\r\n }, \"json\");\r\n }\r\n\r\n $(function () {\r\n adjustTopicComplainFrames();\r\n })\r\n </script>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-10569\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 10569, _tta: Codeforces.tta(), topicRevisionId: 36378, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-10569\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 10569, _tta: Codeforces.tta(), topicRevisionId: 36378, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n </div>\r\n </div>\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 22:13:04</span> (h1).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/81027/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/81027/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/81027/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/81027/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-81027.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'8128758f5b7075a7',t:'MTY5NjcwNTk4NC4yOTcwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"}}},{"rowIdx":1948,"cells":{"problem_id":{"kind":"string","value":"385E"},"contest":{"kind":"string","value":"385"},"problem":{"kind":"string","value":"E"},"lang":{"kind":"string","value":"en"},"problem_title":{"kind":"string","value":"E. Bear in the Field"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">E. Bear in the Field</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Our bear's forest has a checkered field. The checkered field is an <span class=\"tex-span\"><i>n</i> × <i>n</i></span> table, the rows are numbered from 1 to <span class=\"tex-span\"><i>n</i></span> from top to bottom, the columns are numbered from 1 to <span class=\"tex-span\"><i>n</i></span> from left to right. Let's denote a cell of the field on the intersection of row <span class=\"tex-span\"><i>x</i></span> and column <span class=\"tex-span\"><i>y</i></span> by record <span class=\"tex-span\">(<i>x</i>, <i>y</i>)</span>. Each cell of the field contains growing raspberry, at that, the cell <span class=\"tex-span\">(<i>x</i>, <i>y</i>)</span> of the field contains <span class=\"tex-span\"><i>x</i> + <i>y</i></span> raspberry bushes.</p><p>The bear came out to walk across the field. At the beginning of the walk his speed is <span class=\"tex-span\">(<i>dx</i>, <i>dy</i>)</span>. Then the bear spends exactly <span class=\"tex-span\"><i>t</i></span> seconds on the field. Each second the following takes place:</p><ul> <li> Let's suppose that at the current moment the bear is in cell <span class=\"tex-span\">(<i>x</i>, <i>y</i>)</span>. </li><li> First the bear eats the raspberry from all the bushes he has in the current cell. After the bear eats the raspberry from <span class=\"tex-span\"><i>k</i></span> bushes, he increases each component of his speed by <span class=\"tex-span\"><i>k</i></span>. In other words, if before eating the <span class=\"tex-span\"><i>k</i></span> bushes of raspberry his speed was <span class=\"tex-span\">(<i>dx</i>, <i>dy</i>)</span>, then after eating the berry his speed equals <span class=\"tex-span\">(<i>dx</i> + <i>k</i>, <i>dy</i> + <i>k</i>)</span>. </li><li> Let's denote the current speed of the bear <span class=\"tex-span\">(<i>dx</i>, <i>dy</i>)</span> (it was increased after the previous step). Then the bear moves from cell <span class=\"tex-span\">(<i>x</i>, <i>y</i>)</span> to cell <span class=\"tex-span\">(((<i>x</i> + <i>dx</i> - 1) <i>mod</i> <i>n</i>) + 1, ((<i>y</i> + <i>dy</i> - 1) <i>mod</i> <i>n</i>) + 1)</span>. </li><li> Then one additional raspberry bush grows in each cell of the field. </li></ul><p>You task is to predict the bear's actions. Find the cell he ends up in if he starts from cell <span class=\"tex-span\">(<i>sx</i>, <i>sy</i>)</span>. Assume that each bush has infinitely much raspberry and the bear will never eat all of it.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line of the input contains six space-separated integers: <span class=\"tex-span\"><i>n</i></span>, <span class=\"tex-span\"><i>sx</i></span>, <span class=\"tex-span\"><i>sy</i></span>, <span class=\"tex-span\"><i>dx</i></span>, <span class=\"tex-span\"><i>dy</i></span>, <span class=\"tex-span\"><i>t</i></span> <span class=\"tex-span\">(1 ≤ <i>n</i> ≤ 10<sup class=\"upper-index\">9</sup>; 1 ≤ <i>sx</i>, <i>sy</i> ≤ <i>n</i>; - 100 ≤ <i>dx</i>, <i>dy</i> ≤ 100; 0 ≤ <i>t</i> ≤ 10<sup class=\"upper-index\">18</sup>)</span>.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print two integers — the coordinates of the cell the bear will end up in after <span class=\"tex-span\"><i>t</i></span> seconds.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>5 1 2 0 1 2<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>3 1</pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>1 1 1 -1 -1 2<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1 1</pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>Operation <span class=\"tex-span\"><i>a</i> <i>mod</i> <i>b</i></span> means taking the remainder after dividing <span class=\"tex-span\"><i>a</i></span> by <span class=\"tex-span\"><i>b</i></span>. Note that the result of the operation is always non-negative. For example, <span class=\"tex-span\">( - 1) <i>mod</i> 3 = 2</span>.</p><p>In the first sample before the first move the speed vector will equal (3,4) and the bear will get to cell (4,1). Before the second move the speed vector will equal (9,10) and he bear will get to cell (3,1). Don't forget that at the second move, the number of berry bushes increased by 1.</p><p>In the second sample before the first move the speed vector will equal (1,1) and the bear will get to cell (1,1). Before the second move, the speed vector will equal (4,4) and the bear will get to cell (1,1). Don't forget that at the second move, the number of berry bushes increased by 1.</p></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"319cc9f3bc5fc7ba0a48183f9b67f9dc\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - E - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"3200a641fa0ca6f78af7a41b57e5016ab7be9096\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - E - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/73366/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/73366/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/73366/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/73366/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/73366/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/73366/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/73366/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/73366/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/73366/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/73366/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/73366/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/73366/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/73366/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/73366/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/sidebar-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/a037fe51637846d9c7c725713cd840ea/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='319cc9f3bc5fc7ba0a48183f9b67f9dc'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/73366/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/73366/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fcontest%2F385%2Fproblem%2FE%3Flocale%3Den\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"current\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='319cc9f3bc5fc7ba0a48183f9b67f9dc'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:100%;\"><a style=\"color: black\" href=\"/contest/385\">Codeforces Round 226 (Div. 2)</a></th>\n </tr>\n <tr>\n <td class=\"left bottom\" colspan=\"1\"><span class=\"contest-state-phase\">Finished</span></td>\n </tr>\n </tbody>\n </table>\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Practice?\n <div class=\"top-links\">\n </div>\n </div>\n<div>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Want to solve the contest problems after the official contest ends? Just register for practice and you will be able to submit solutions.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"\" method=\"post\"><input type='hidden' name='csrf_token' value='319cc9f3bc5fc7ba0a48183f9b67f9dc'/>\r\n <input type=\"hidden\" name=\"action\" value=\"registerForPractice\"/>\r\n <input type=\"submit\" name=\"submit\" value=\"Register for practice\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div> \r\n</div>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox ContestVirtualFrame borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Virtual participation <i class=\"sidebar-caption-icon las la-angle-down\"></i>\r\n\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\" \"\r\n\r\n data-page-url=\"/data/sidebarFrames\"\r\n\r\n>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests.\n\nIf you've seen these problems, a virtual contest is not for you - solve these problems in the archive.\n\nIf you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.\n\nNever use someone else's code, read the tutorials or communicate with other person during a virtual contest.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"/contest/385/virtual\" method=\"get\">\r\n <input type=\"submit\" name=\"submit\" value=\"Start virtual contest\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div>\r\n</div>\r\n <script>\r\n $(function () {\r\n $(\".ContestVirtualFrame .sidebar-caption-icon\").click(function() {\r\n $(this).toggleClass(\"la-angle-down la-angle-right\");\r\n const $target = $(this).parent().next();\r\n $target.toggle();\r\n const dataPageUrl = $target.attr(\"data-page-url\");\r\n const collapsed = $(this).hasClass(\"la-angle-right\");\r\n const params = {\r\n action: \"setCollapsed\",\r\n sidebarFrameSimpleClassName: \"ContestVirtualFrame\",\r\n collapsed\r\n };\r\n $.each($target[0].attributes, function(i, a) {\r\n const name = a.name;\r\n if (name.startsWith(\"data-extra-key-\")) {\r\n const key = a.value;\r\n const keyIndex = parseInt(name.substring(\"data-extra-key-\".length));\r\n const value = $target.attr(\"data-extra-value-\" + keyIndex);\r\n params[key] = value;\r\n }\r\n });\r\n $.post(dataPageUrl, params, function (result) {\r\n if (result[\"success\"] !== \"true\") {\r\n Codeforces.showMessage(\"Failed to save collapsed state.\");\r\n }\r\n }, \"json\");\r\n return false;\r\n });\r\n })\r\n </script>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Problem tags\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Mathematics including integration, differential equations, etc\">\r\n math\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Matrix multiplication, determinant, Cramer's rule, systems of linear equations\">\r\n matrices\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Difficulty\">\r\n *2300\r\n</span>\r\n </div>\n <div style=\"clear:both;text-align:right;font-size:1.1rem;\">\r\n <span title=\"Please login into the Codeforces\" class=\"notice\">No tag edit access</span>\r\n </div>\r\n</div>\r\n </div>\n\r\n<form id=\"addTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='319cc9f3bc5fc7ba0a48183f9b67f9dc'/>\r\n <input name=\"action\" type=\"hidden\" value=\"addTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"5935\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<form id=\"removeTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='319cc9f3bc5fc7ba0a48183f9b67f9dc'/>\r\n <input name=\"action\" type=\"hidden\" value=\"removeTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"5935\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<script type=\"text/javascript\">\r\n $(\".tag-box img\").click(function () {\r\n var tagName = $(this).attr(\"value\");\r\n Codeforces.confirm(\"Are you sure you want to remove this tag?\", function () {\r\n $(\"#removeTagForm input[name=tagName]\").val(tagName);\r\n $(\"#removeTagForm\").submit();\r\n }, function () {\r\n }, \"Yes\", \"No\");\r\n });\r\n\r\n $(\"#addTagLink\").click(function () {\r\n $(this).hide();\r\n $(\"#addTagLabel\").show();\r\n return false;\r\n });\r\n\r\n $(\"#addTagSelect\").change(function () {\r\n var tagName = $(this).val();\r\n if (tagName === \"\") {\r\n $(\"#addTagLabel\").hide();\r\n $(\"#addTagLink\").show();\r\n } else {\r\n $(\"#addTagForm input[name=tagName]\").val(tagName);\r\n $(\"#addTagForm\").submit();\r\n }\r\n });\r\n</script>\r\n\r\n<style type=\"text/css\">\r\n#new-resource-form tr td {\r\npadding-top: 0.5em;\r\n}\r\n#new-resource-form input:not([type=\"submit\"]) {\r\nfont-size: 0.8em;\r\n}\r\n#new-resource-form select {\r\nfont-size: 0.8em;\r\n}\r\n.new-resource-error {\r\nfont-size: 0.8em;\r\n}\r\n.resource-locale {\r\ncolor: #666;\r\nfont-family: Consolas, \"Andale Mono WT\", \"Andale Mono\", \"Lucida Console\", \"Lucida Sans Typewriter\", \"DejaVu Sans Mono\", \"Bitstream Vera Sans Mono\", \"Liberation Mono\", \"Nimbus Mono L\", Monaco, \"Courier New\", Courier, monospace;\r\n}\r\n</style>\r\n<div class=\"roundbox sidebox sidebar-menu borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Contest materials\n<div class=\"top-links\">\n</div>\n</div>\n<ul>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/10512\" title=\"Codeforces Round #226 (Div. 2)\" target=\"_blank\">Announcement</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"2193:2194\" resourceName=\"Announcement\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/10514\" title=\"Codeforces Round #226 (Div. 2) — Editorial\" target=\"_blank\">Tutorial</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"2197:2198\" resourceName=\"Tutorial\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n</ul>\r\n</div></div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li class=\"current selectedLava\"><a\r\n href=\"/contest/385\">Problems</a></li>\r\n <li><a\r\n href=\"/contest/385/submit\">Submit Code</a></li>\r\n <li><a\r\n href=\"/contest/385/my\">My Submissions</a></li>\r\n <li><a\r\n href=\"/contest/385/status\">Status</a></li>\r\n <li><a\r\n href=\"/contest/385/hacks\">Hacks</a></li>\r\n <li><a\r\n href=\"/contest/385/room/1\">Room</a></li>\r\n <li><a\r\n href=\"/contest/385/standings\">Standings</a></li>\r\n <li><a\r\n href=\"/contest/385/customtest\">Custom Invocation</a></li>\r\n</ul>\r\n</div>\n\r\n <style>\r\n #facebox .content:has(.diff-popup) {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n }\r\n\r\n .testCaseMarker {\r\n position: absolute;\r\n font-weight: bold;\r\n font-size: 1rem;\r\n }\r\n\r\n .diff-popup {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n display: none;\r\n overflow: auto;\r\n }\r\n\r\n .input-output-copier {\r\n font-size: 1.2rem;\r\n float: right;\r\n color: #888 !important;\r\n cursor: pointer;\r\n border: 1px solid rgb(185, 185, 185);\r\n padding: 3px;\r\n margin: 1px;\r\n line-height: 1.1rem;\r\n text-transform: none;\r\n }\r\n\r\n .input-output-copier:hover {\r\n background-color: #def;\r\n }\r\n\r\n .test-explanation textarea {\r\n width: 100%;\r\n height: 1.5em;\r\n }\r\n\r\n .pending-submission-message {\r\n color: darkorange !important;\r\n }\r\n </style>\r\n <script>\r\n const OPENING_SPACE = String.fromCharCode(1001);\r\n const CLOSING_SPACE = String.fromCharCode(1002);\r\n\r\n const nodeToText = function (node, pre) {\r\n let result = [];\r\n\r\n if (node.tagName === \"SCRIPT\" || node.tagName === \"math\"\r\n || (node.classList && node.classList.contains(\"input-output-copier\")))\r\n return [];\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(OPENING_SPACE);\r\n }\r\n\r\n if (node.nodeType === Node.TEXT_NODE) {\r\n let s = node.textContent;\r\n if (!pre) {\r\n s = s.replace(/\\s+/g, \" \");\r\n }\r\n if (s.length > 0) {\r\n result.push(s);\r\n }\r\n }\r\n\r\n if (pre && node.tagName === \"BR\") {\r\n result.push(\"\\n\");\r\n }\r\n\r\n node.childNodes.forEach(function (child) {\r\n result.push(nodeToText(child, node.tagName === \"PRE\").join(\"\"));\r\n });\r\n\r\n if (node.tagName === \"DIV\"\r\n || node.tagName === \"P\"\r\n || node.tagName === \"PRE\"\r\n || node.tagName === \"UL\"\r\n || node.tagName === \"LI\"\r\n ) {\r\n result.push(\"\\n\");\r\n }\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(CLOSING_SPACE);\r\n }\r\n\r\n return result;\r\n }\r\n\r\n const isSpecial = function (c) {\r\n return c === ',' || c === '.' || c === ';' || c === ')' || c === ' ';\r\n }\r\n\r\n const convertStatementToText = function(statmentNode) {\r\n const text = nodeToText(statmentNode, false).join(\"\").replace(/ +/g, \" \").replace(/\\n\\n+/g, \"\\n\\n\");\r\n let result = [];\r\n for (let i = 0; i < text.length; i++) {\r\n const c = text.charAt(i);\r\n if (c === OPENING_SPACE) {\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"E\" data-uuid=\"ps_014aebf38ad1371cc25cdb748b90328a99077523\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">E. Bear in the Field</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Our bear's forest has a checkered field. The checkered field is an <span class=\"tex-span\"><i>n</i> × <i>n</i></span> table, the rows are numbered from 1 to <span class=\"tex-span\"><i>n</i></span> from top to bottom, the columns are numbered from 1 to <span class=\"tex-span\"><i>n</i></span> from left to right. Let's denote a cell of the field on the intersection of row <span class=\"tex-span\"><i>x</i></span> and column <span class=\"tex-span\"><i>y</i></span> by record <span class=\"tex-span\">(<i>x</i>, <i>y</i>)</span>. Each cell of the field contains growing raspberry, at that, the cell <span class=\"tex-span\">(<i>x</i>, <i>y</i>)</span> of the field contains <span class=\"tex-span\"><i>x</i> + <i>y</i></span> raspberry bushes.</p><p>The bear came out to walk across the field. At the beginning of the walk his speed is <span class=\"tex-span\">(<i>dx</i>, <i>dy</i>)</span>. Then the bear spends exactly <span class=\"tex-span\"><i>t</i></span> seconds on the field. Each second the following takes place:</p><ul> <li> Let's suppose that at the current moment the bear is in cell <span class=\"tex-span\">(<i>x</i>, <i>y</i>)</span>. </li><li> First the bear eats the raspberry from all the bushes he has in the current cell. After the bear eats the raspberry from <span class=\"tex-span\"><i>k</i></span> bushes, he increases each component of his speed by <span class=\"tex-span\"><i>k</i></span>. In other words, if before eating the <span class=\"tex-span\"><i>k</i></span> bushes of raspberry his speed was <span class=\"tex-span\">(<i>dx</i>, <i>dy</i>)</span>, then after eating the berry his speed equals <span class=\"tex-span\">(<i>dx</i> + <i>k</i>, <i>dy</i> + <i>k</i>)</span>. </li><li> Let's denote the current speed of the bear <span class=\"tex-span\">(<i>dx</i>, <i>dy</i>)</span> (it was increased after the previous step). Then the bear moves from cell <span class=\"tex-span\">(<i>x</i>, <i>y</i>)</span> to cell <span class=\"tex-span\">(((<i>x</i> + <i>dx</i> - 1) <i>mod</i> <i>n</i>) + 1, ((<i>y</i> + <i>dy</i> - 1) <i>mod</i> <i>n</i>) + 1)</span>. </li><li> Then one additional raspberry bush grows in each cell of the field. </li></ul><p>You task is to predict the bear's actions. Find the cell he ends up in if he starts from cell <span class=\"tex-span\">(<i>sx</i>, <i>sy</i>)</span>. Assume that each bush has infinitely much raspberry and the bear will never eat all of it.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line of the input contains six space-separated integers: <span class=\"tex-span\"><i>n</i></span>, <span class=\"tex-span\"><i>sx</i></span>, <span class=\"tex-span\"><i>sy</i></span>, <span class=\"tex-span\"><i>dx</i></span>, <span class=\"tex-span\"><i>dy</i></span>, <span class=\"tex-span\"><i>t</i></span> <span class=\"tex-span\">(1 ≤ <i>n</i> ≤ 10<sup class=\"upper-index\">9</sup>; 1 ≤ <i>sx</i>, <i>sy</i> ≤ <i>n</i>; - 100 ≤ <i>dx</i>, <i>dy</i> ≤ 100; 0 ≤ <i>t</i> ≤ 10<sup class=\"upper-index\">18</sup>)</span>.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print two integers — the coordinates of the cell the bear will end up in after <span class=\"tex-span\"><i>t</i></span> seconds.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>5 1 2 0 1 2<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>3 1</pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>1 1 1 -1 -1 2<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1 1</pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>Operation <span class=\"tex-span\"><i>a</i> <i>mod</i> <i>b</i></span> means taking the remainder after dividing <span class=\"tex-span\"><i>a</i></span> by <span class=\"tex-span\"><i>b</i></span>. Note that the result of the operation is always non-negative. For example, <span class=\"tex-span\">( - 1) <i>mod</i> 3 = 2</span>.</p><p>In the first sample before the first move the speed vector will equal (3,4) and the bear will get to cell (4,1). Before the second move the speed vector will equal (9,10) and he bear will get to cell (3,1). Don't forget that at the second move, the number of berry bushes increased by 1.</p><p>In the second sample before the first move the speed vector will equal (1,1) and the bear will get to cell (1,1). Before the second move, the speed vector will equal (4,4) and the bear will get to cell (1,1). Don't forget that at the second move, the number of berry bushes increased by 1.</p></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=E]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== statementText) {\r\n $problem.find(\".diff-notifier\").show();\r\n\r\n $problem.find(\".diff-notifier-close\").click(function() {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n $problem.find(\".diff-notifier\").hide();\r\n });\r\n\r\n $problem.find(\"a.view-changes\").click(function() {\r\n $.post(\"/data/diff\", {action: \"getDiff\", a: previousStatementText, b: statementText}, function (result) {\r\n if (result[\"success\"] === \"true\") {\r\n Codeforces.facebox(\".diff-popup\", \"//codeforces.org/s/73366\");\r\n $(\"#facebox .diff-popup\").html(result[\"diff\"]);\r\n }\r\n }, \"json\");\r\n });\r\n }\r\n } else {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n }\r\n });\r\n });\r\n </script>\r\n\r\n\r\n<script type=\"text/javascript\">\r\n $(document).ready(function () {\r\n window.changedTests = new Set();\r\n\r\n function endsWith(string, suffix) {\r\n return string.indexOf(suffix, string.length - suffix.length) !== -1;\r\n }\r\n\r\n const inputFileDiv = $(\"div.input-file\");\r\n const inputFile = inputFileDiv.text();\r\n const outputFileDiv = $(\"div.output-file\");\r\n const outputFile = outputFileDiv.text();\r\n\r\n\r\n if (!endsWith(inputFile, \"standard input\")\r\n && !endsWith(inputFile, \"standard input\")) {\r\n inputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n if (!endsWith(outputFile, \"standard output\")\r\n && !endsWith(outputFile, \"standard output\")) {\r\n outputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n const titleDiv = $(\"div.header div.title\");\r\n\r\n\r\n\r\n String.prototype.replaceAll = function (search, replace) {\r\n return this.split(search).join(replace);\r\n };\r\n\r\n $(\".sample-test .title\").each(function () {\r\n const preId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n const cpyId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n\r\n $(this).parent().find(\"pre\").attr(\"id\", preId);\r\n const $copy = $(\"<div title='Copy' data-clipboard-target='#\" + preId + \"' id='\" + cpyId + \"' class='input-output-copier'>Copy</div>\");\r\n $(this).append($copy);\r\n\r\n const clipboard = new Clipboard('#' + cpyId, {\r\n text: function (trigger) {\r\n const pre = document.querySelector('#' + preId);\r\n const lines = pre.querySelectorAll(\".test-example-line\");\r\n return Codeforces.filterClipboardText(pre.innerText, lines.length);\r\n }\r\n });\r\n\r\n const isInput = $(this).parent().hasClass(\"input\");\r\n\r\n clipboard.on('success', function (e) {\r\n if (isInput) {\r\n Codeforces.showMessage(\"The example input has been copied into the clipboard\");\r\n } else {\r\n Codeforces.showMessage(\"The example output has been copied into the clipboard\");\r\n }\r\n e.clearSelection();\r\n });\r\n });\r\n\r\n $(\".test-form-item input\").change(function () {\r\n addPendingSubmissionMessage($($(this).closest(\"form\")), \"You changed the answer, do not forget to submit it if you want to save the changes\");\r\n const index = $(this).closest(\".problemindexholder\").attr(\"problemindex\");\r\n let test = \"\";\r\n $(this).closest(\"form input\").each(function () {\r\n const test_ = $(this).attr(\"name\");\r\n if (test_ && test_.substring(0, 4) === \"test\") {\r\n test = test_;\r\n }\r\n });\r\n if (index.length > 0 && test.length > 0) {\r\n const indexTest = index + \"::\" + test;\r\n window.changedTests.add(indexTest);\r\n }\r\n });\r\n\r\n $(window).on('beforeunload', function () {\r\n if (window.changedTests.size > 0) {\r\n return 'Dialog text here';\r\n }\r\n });\r\n\r\n autosize($('.test-explanation textarea'));\r\n\r\n $(\".test-example-line\").hover(function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n let top = 1E20;\r\n let left = 1E20;\r\n let problem = $(this).closest(\".problemindexholder\");\r\n $(this).closest(\".input\").find(\".\" + clazz).css(\"background-color\", \"#FFFDE7\").each(function() {\r\n top = Math.min(top, $(this).offset().top);\r\n left = Math.min(left, $(this).offset().left);\r\n });\r\n let testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n if (testCaseMarker.length === 0) {\r\n const html = \"<div class=\\\"testCaseMarker testCaseMarker_\" + end + \" notice\\\"></div>\";\r\n problem.append($(html));\r\n testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n }\r\n if (testCaseMarker) {\r\n testCaseMarker.show()\r\n .offset({top, left: left - 20})\r\n .text(end);\r\n }\r\n }\r\n }\r\n });\r\n }, function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n $(\".\" + clazz).css(\"background-color\", \"\");\r\n $(this).closest(\".problemindexholder\").find(\".testCaseMarker_\" + end).hide();\r\n }\r\n }\r\n });\r\n });\r\n\r\n });\r\n</script>\r\n\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 05:38:16</span> (j3).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/73366/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/73366/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/73366/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/73366/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-73366.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'8122c4558d699d8d',t:'MTY5NjY0NjI5Ni4wNDgwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"},"long_tags":{"kind":"string","value":"[\"Mathematics including integration, differential equations, etc\", \"Matrix multiplication, determinant, Cramer's rule, systems of linear equations\"]"},"short_tags":{"kind":"string","value":"[\"math\", \"matrices\", \"*2300\"]"},"tutorial_link":{"kind":"string","value":"https://codeforces.com/blog/entry/10514"},"tutorial_page":{"kind":"string","value":"\r\n\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"b0edd04b6e615eea61c4a67daabca579\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"h1\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Codeforces Round #226 (Div. 2) — Editorial - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n \n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Codeforces Round #226 (Div. 2) — Editorial - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/81027/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/81027/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/81027/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/81027/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/81027/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/81027/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/81027/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/81027/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/81027/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/81027/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/81027/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/81027/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/81027/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/81027/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/573cedc6b04c15481941f418269f4057/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='b0edd04b6e615eea61c4a67daabca579'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/81027/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fblog%2Fentry%2F10514\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='b0edd04b6e615eea61c4a67daabca579'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Pay attention\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n <div style=\"text-align:center;border-bottom: 1px solid rgb(185, 185, 185);margin:0 -0.5em 0.5em -0.5em;padding: 0 1em 0.5em 1em;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 1, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:51:56</span><br/><a href=\"/contestRegistration/1876\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n <div style=\"text-align:center;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 2, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:51:56</span><br/><a href=\"/contestRegistration/1877\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='b0edd04b6e615eea61c4a67daabca579'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n </label>\r\n </div>\r\n <div style=\"padding: 0 1em 1em 1em;text-align:right;\">\r\n <input style=\"height:1.65em;padding:0 0.75em;\" type=\"submit\" value=\"Find\"/>\r\n </div>\r\n </form>\r\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".handleBox\").autocomplete(\"/data/handles\", {\r\n delay: 200,\r\n width: 200,\r\n selectFirst: false,\r\n matchContains: true,\r\n minChars: 3\r\n });\r\n $(\".handleForm\").attr(\"autocomplete\", \"off\").submit(function () {\r\n var link = \"/profile/userHandle\".replace(\r\n \"userHandle\", $(this).find(\".handleBox\").val()\r\n );\r\n window.location = link;\r\n return false;\r\n });\r\n });\n </script>\n\r\n\r\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Recent actions\n <div class=\"top-links\">\n </div>\n </div>\n <div class=\"recent-actions\">\r\n <ul>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/121073\">Meta Hacker Cup 2023 Round 1</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/.Danet\" title=\"Expert .Danet\" class=\"rated-user user-blue\">.Danet</a> →\r\n <a href=\"/blog/entry/121172\">[TLE on pretest1]</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\" class=\"rated-user user-red\">Pyqe</a> →\r\n <a href=\"/blog/entry/121025\">Codeforces Round #902 (Div. 1, Div. 2, based on COMPFEST 15 — Final Round)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pranshu_Pandya\" title=\"Specialist Pranshu_Pandya\" class=\"rated-user user-cyan\">Pranshu_Pandya</a> →\r\n <a href=\"/blog/entry/121171\">An Interesting Tree Problem</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/sszcdjr\" title=\"Master sszcdjr\" class=\"rated-user user-orange\">sszcdjr</a> →\r\n <a href=\"/blog/entry/119859\">Codeforces Round 896 (Div. 1, Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/119880\">It's Happening! Meta Hacker Cup 2023 Schedule</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/DaviddeGea1\" title=\"Expert DaviddeGea1\" class=\"rated-user user-blue\">DaviddeGea1</a> →\r\n <a href=\"/blog/entry/70917\">Number of ways of dividing an array into 2 parts such that sum of each part is > k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bekh\" title=\"Master Bekh\" class=\"rated-user user-orange\">Bekh</a> →\r\n <a href=\"/blog/entry/74245\">Questions and doubts regarding Aliens DP trick</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a> →\r\n <a href=\"/blog/entry/8192\">Codeforces Round #190 — Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/hocky\" title=\"Candidate Master hocky\" class=\"rated-user user-violet\">hocky</a> →\r\n <a href=\"/blog/entry/95323\">FBHC wuining uw Day? Incwease uw stacc size! (ㅅ´ ˘ `)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/liouzhou_101\" title=\"International Master liouzhou_101\" class=\"rated-user user-orange\">liouzhou_101</a> →\r\n <a href=\"/blog/entry/87598\">Editorial of Codeforces Round #700</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/yeon_gist\" title=\"Newbie yeon_gist\" class=\"rated-user user-gray\">yeon_gist</a> →\r\n <a href=\"/blog/entry/121170\">plusMinusPermutation computing error</a>\r\n <img alt=\"Text created or updated\" title=\"Text created or updated\" src=\"//codeforces.org/s/81027/images/icons/x-update-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/altforminuscontribution\" title=\"Newbie altforminuscontribution\" class=\"rated-user user-gray\">altforminuscontribution</a> →\r\n <a href=\"/blog/entry/121162\">My screen get unexpectedly big, what should I do</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/atcoder_official\" title=\"Unrated, atcoder_official\" class=\"rated-user user-black\">atcoder_official</a> →\r\n <a href=\"/blog/entry/121120\">We will hold UNIQUE VISION Programming Contest 2023 Autumn(AtCoder Beginner Contest 323)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/YouStill_DontKnowMeYet\" title=\"Candidate Master YouStill_DontKnowMeYet\" class=\"rated-user user-violet\">YouStill_DontKnowMeYet</a> →\r\n <a href=\"/blog/entry/117659\">[GYM] Al-Baath Collegiate Programming Contest 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/ankancool\" title=\"Expert ankancool\" class=\"rated-user user-blue\">ankancool</a> →\r\n <a href=\"/blog/entry/121136\">Invitation to AstroByte 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/GeZhiyuan\" title=\"Grandmaster GeZhiyuan\" class=\"rated-user user-red\">GeZhiyuan</a> →\r\n <a href=\"/blog/entry/120943\">Codeforces Round 901 (Div. 1, Div. 2) Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a> →\r\n <a href=\"/blog/entry/120772\">PSA: Increase your stack size before the Meta Hacker Cup, here's how</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/dino_merlin\" title=\"Expert dino_merlin\" class=\"rated-user user-blue\">dino_merlin</a> →\r\n <a href=\"/blog/entry/121145\">Intuitive approach for CEOI Kangaroo?</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/icecuber\" title=\"Grandmaster icecuber\" class=\"rated-user user-red\">icecuber</a> →\r\n <a href=\"/blog/entry/70018\">CSES DP section editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bn00b\" title=\"Newbie Bn00b\" class=\"rated-user user-gray\">Bn00b</a> →\r\n <a href=\"/blog/entry/98820\">[FEATURE REQUEST : ATCODER] TOPICS TAGS AND SORTING BY SOLVE COUNT</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a> →\r\n <a href=\"/blog/entry/121163\">AtCoder Regular Contest 166 Announcement</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/windva\" title=\"Grandmaster windva\" class=\"rated-user user-red\">windva</a> →\r\n <a href=\"/blog/entry/120644\">Codeforces Round 899 (Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Misa-Misa\" title=\"Expert Misa-Misa\" class=\"rated-user user-blue\">Misa-Misa</a> →\r\n <a href=\"/blog/entry/121157\">Someone please help me understand this.</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/shivam565\" title=\"Specialist shivam565\" class=\"rated-user user-cyan\">shivam565</a> →\r\n <a href=\"/blog/entry/108348\">Total number of subarrays with sum atmost k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n </ul>\r\n </div>\r\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/recent-actions\">Detailed →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n</div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li><a\r\n href=\"/profile/CleRIC\">CleRIC</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/CleRIC\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/CleRIC\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/CleRIC\">Submissions</a></li>\r\n <li><a\r\n href=\"/groups/with/CleRIC\">Groups</a></li>\r\n <li><a\r\n href=\"/contests/with/CleRIC\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/CleRIC\">Problemsetting</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/CleRIC\" style=\"text-decoration:none;color:black !important;\">CleRIC's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"10569\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/10514\"> <p>Codeforces Round #226 (Div. 2) — Editorial</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/CleRIC\" title=\"Candidate Master CleRIC\" class=\"rated-user user-violet\">CleRIC</a>,\r\n <span class=\"format-humantime\" title=\"Jan/23/2014 19:33\">10 years ago</span>,\r\n translation,\r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p><a href=\"/contest/385/problem/A\" title=\"Codeforces Round 226 (Div. 2)\">385A - Bear and Raspberry</a></p><p>In this task required to understand that the answer max(<span class=\"tex-span\"><i>a</i>[<i>i</i>] - <i>a</i>[<i>i</i> - 1] - <i>c</i></span>),<span class=\"tex-span\"><i>i</i></span> = <span class=\"tex-span\">2..<i>n</i></span> and don't forget that the answer not negative as Bear can not borrow in the debt barrel of honey.</p><p><a href=\"/contest/385/problem/B\" title=\"Codeforces Round 226 (Div. 2)\">385B - Bear and Strings</a></p><p>In this problem you could write a better solution than the naive. To do this, you can iterate through the first cycle of the left index <span class=\"tex-span\"><i>l</i></span> considered substring and the second cycle of the right index <span class=\"tex-span\"><i>r</i></span> considered substring <span class=\"tex-span\">(<i>l</i> ≤ <i>r</i>)</span>. If any position has been substring "bear", means all the strings <span class=\"tex-span\"><i>x</i>(<i>l</i>, <i>j</i>)</span> <span class=\"tex-span\">(<i>i</i> ≤ <i>j</i>)</span>, also contain "bear" as a substring. So we can add to the answer <span class=\"tex-span\">|<i>s</i>| - <i>j</i> + 1</span> and exit from the second cycle. Also needed to understand, that if the string <span class=\"tex-span\"><i>x</i>(<i>l</i>, <i>j</i>)</span> was not a substring "bear", then in row <span class=\"tex-span\"><i>x</i>(<i>l</i>, <i>j</i> + 1)</span> substring "bear" could appear only in the last four characters.</p><p><a href=\"/contest/385/problem/C\" title=\"Codeforces Round 226 (Div. 2)\">385C - Bear and Prime Numbers</a></p><p>In order to solve given problem, contestant should solve several subproblems :</p><p>1) First one is to compute amount of entries of each natural number between <span class=\"tex-span\">2</span> and <span class=\"tex-span\">10<sup class=\"upper-index\">7</sup></span> in given list. This subproblem can be solved by creating array <span class=\"tex-span\"><i>count</i></span> of <span class=\"tex-span\">10<sup class=\"upper-index\">7</sup></span> elements and increasing corresponding element when scanning input.</p><p>2) Second one is to compute <span class=\"tex-span\"><i>f</i>(<i>n</i>)</span>.</p><p>First of all, we need to find all primes less than <span class=\"tex-span\">10<sup class=\"upper-index\">7</sup></span> and then for each prime <span class=\"tex-span\"><i>n</i></span> compute <span class=\"tex-span\"><i>f</i>(<i>n</i>)</span>.</p><p>How to compute <span class=\"tex-span\"><i>f</i>(2)</span>? We should sum <span class=\"tex-span\"><i>count</i>[2]</span>,<span class=\"tex-span\"><i>count</i>[4]</span>,<span class=\"tex-span\"><i>count</i>[6]</span>,<span class=\"tex-span\"><i>count</i>[8]</span>,...</p><p>How to compute <span class=\"tex-span\"><i>f</i>(5)</span>? We should sum <span class=\"tex-span\"><i>count</i>[5]</span>,<span class=\"tex-span\"><i>count</i>[10]</span>,<span class=\"tex-span\"><i>count</i>[15]</span>,<span class=\"tex-span\"><i>count</i>[20]</span>,...</p><p>How to compute <span class=\"tex-span\"><i>f</i>(<i>n</i>)</span>? We should sum <span class=\"tex-span\"><i>count</i>[<i>n</i>]</span>,<span class=\"tex-span\"><i>count</i>[2·<i>n</i>]</span>,<span class=\"tex-span\"><i>count</i>[3·<i>n</i>]</span>,<span class=\"tex-span\"><i>count</i>[4·<i>n</i>]</span>,...</p><p>It can be seen that given algo is very similar to Sieve of Eratosthenes. (Info here <a href=\"http://e-maxx.ru/algo/eratosthenes_sieve\">http://e-maxx.ru/algo/eratosthenes_sieve</a>) So we can use this algo if we change it a little bit. Also, we will store results of calculation in array, e.g. <span class=\"tex-span\"><i>pre</i></span>. Namely, <span class=\"tex-span\"><i>pre</i>[<i>n</i>]</span> = <span class=\"tex-span\"><i>f</i>(<i>n</i>)</span>.</p><p>3) Now we can calculate partial sums of <span class=\"tex-span\"><i>pre</i></span> array. It can be made in a single pass just adding <span class=\"tex-span\"><i>pre</i>[<i>i</i> - 1]</span> to <span class=\"tex-span\"><i>pre</i>[<i>i</i>]</span>.</p><p>4) If we know partial sums of array then we can calculate sum of array elements between <span class=\"tex-span\"><i>l</i></span> and <span class=\"tex-span\"><i>r</i></span> in time proportional <span class=\"tex-span\"><i>O</i>(1)</span>, just calculate <span class=\"tex-span\"><i>pre</i>[<i>r</i>] - <i>pre</i>[<i>l</i> - 1]</span>.</p><p>5) Now we can read queries and immediately response to them. You shouldn't forget that right boundaries of intervals can be greater than <span class=\"tex-span\">10<sup class=\"upper-index\">7</sup></span>, so you can always decrease it to <span class=\"tex-span\">10<sup class=\"upper-index\">7</sup></span>, because all numbers in given list are less than <span class=\"tex-span\">10<sup class=\"upper-index\">7</sup></span>.</p><p><a href=\"/contest/385/problem/D\" title=\"Codeforces Round 226 (Div. 2)\">385D - Bear and Floodlight</a></p><p>In this task, it is crucial to understand that whether there is lighted part of road with length <span class=\"tex-span\"><i>dist</i></span> then next part should be lit in a such way that leftmost lighted point is touching with <span class=\"tex-span\"><i>dist</i></span>.</p><p>Let's suppose that road is lit from <span class=\"tex-span\"><i>l</i></span> to <span class=\"tex-span\"><i>d</i></span>. How we can find rightmost point on X axis that would be lit by next floodlight?</p><p>We can just use concepts of vector and rotation matrix.</p><p>Let's find vector <span class=\"tex-span\">(<i>dx</i>, <i>dy</i>)</span> from floodlight to point on X axis <span class=\"tex-span\">(<i>d</i>, 0)</span>. <span class=\"tex-span\">(<i>dx</i>, <i>dy</i>)</span> = <span class=\"tex-span\">(<i>d</i> - <i>x</i>, 0 - <i>y</i>)</span>.</p><p>Next point to rotate vector by <span class=\"tex-span\"><i>angle</i></span> degrees. We can use rotation matrix for this purpose.</p><p><span class=\"tex-span\">(<i>dx</i>, <i>dy</i>)</span> = <span class=\"tex-span\">(<i>dx</i>·<i>cos</i>(<i>angle</i>) - <i>dy</i>·<i>sin</i>(<i>angle</i>), <i>dx</i>·<i>sin</i>(<i>angle</i>) + <i>dy</i>·<i>cos</i>(<i>angle</i>))</span></p><p>Next, we should make second component <span class=\"tex-span\"><i>dy</i></span> of <span class=\"tex-span\">(<i>dx</i>, <i>dy</i>)</span> equal to <span class=\"tex-span\">1</span> by multiplying on coefficient <span class=\"tex-span\"><i>k</i></span>.</p><p>Now we can determine rightmost lighted point of X axis. It is <span class=\"tex-span\"><i>x</i> - <i>y</i>·<i>dx</i></span>.</p><p>You shouldn't forget that there is possibility for rightmost point to be infinitely far point.</p><p>From now on we can forget about geometry in this task.</p><p>Let's find fast way to determine optimal order of floodlights.</p><p>To achieve this goal, we can use dynamic programming approach. Namely, let's calculate answer for subsets of floodlights. Each subset would be represented as integer where <span class=\"tex-span\"><i>k</i></span> bit would be <span class=\"tex-span\">1</span> if <span class=\"tex-span\"><i>k</i></span> floodlight is presented in subset and <span class=\"tex-span\">0</span> if it is not, i.e. so named binary mask.</p><p>For example, <span class=\"tex-span\"><i>dp</i>[6]</span> — (<span class=\"tex-span\">6</span> — <span class=\"tex-span\">110<sub class=\"lower-index\">2</sub></span>) is optimal answer for subset from <span class=\"tex-span\">2</span> and <span class=\"tex-span\">3</span> floodlight.</p><p>Now, let's look through subsets <span class=\"tex-span\"><i>i</i></span> in <span class=\"tex-span\"><i>dp</i>[<i>i</i>]</span>. In subset <span class=\"tex-span\"><i>i</i></span> let's go through absent floodlights <span class=\"tex-span\"><i>j</i></span> and update result for subset where <span class=\"tex-span\"><i>j</i></span> floodlight is present, i.e. dp[ <span class=\"tex-span\"><i>i</i></span> or <span class=\"tex-span\">2<sup class=\"upper-index\"><i>j</i></sup></span> ] = max(dp[ <span class=\"tex-span\"><i>i</i></span> or <span class=\"tex-span\">2<sup class=\"upper-index\"><i>j</i></sup></span>], dp[ <span class=\"tex-span\"><i>i</i></span> ] + calc_rightmost_lighted_point() ). As we can calculate rightmost lighted point, so updating of answer shouldn't be a problem.</p><p><a href=\"/contest/385/problem/E\" title=\"Codeforces Round 226 (Div. 2)\">385E - Bear in the Field</a></p><p>In this task there are several problems that should be concerned:</p><p>1) Simple modeling of bear movement would cause TLE due to <span class=\"tex-span\"><i>t</i></span> <span class=\"tex-span\"> ≤ </span> <span class=\"tex-span\">10<sup class=\"upper-index\">18</sup></span>.</p><p>2) Task can't be solved by separating <span class=\"tex-span\"><i>x</i></span> and <span class=\"tex-span\"><i>y</i></span> axes because <span class=\"tex-span\"><i>x</i></span> and <span class=\"tex-span\"><i>y</i></span> depends on each other.</p><p>3) Also, we can't use standart method of cycle finding via modeling for a short time and checking on collisions because coordinates limitations are very large.</p><p>Let's say we have matrix <span class=\"tex-span\">(<i>x</i><sub class=\"lower-index\"><i>i</i></sub>, <i>y</i><sub class=\"lower-index\"><i>i</i></sub>, <i>dx</i><sub class=\"lower-index\"><i>i</i></sub>, <i>dy</i><sub class=\"lower-index\"><i>i</i></sub>, <i>t</i><sub class=\"lower-index\"><i>i</i></sub>, 1)</span>.</p><p>If we multiply previous matrix by following matrix long long base[6][6] = {</p><p>{2,1,1,1,0,0},</p><p>{1,2,1,1,0,0},</p><p>{1,0,1,0,0,0},</p><p>{0,1,0,1,0,0},</p><p>{0,0,1,1,1,0},</p><p>{0,0,2,2,1,1} };</p><p>we will have get parameters on next step.</p><p>Where did the matrix? Let us write out how to change parameters with each step and see the similarity matrix.</p><p><span class=\"tex-span\"><i>x</i></span> = <span class=\"tex-span\">2·<i>x</i></span> + <span class=\"tex-span\">1·<i>y</i></span> + <span class=\"tex-span\">1·<i>dx</i></span> + <span class=\"tex-span\">0·<i>dy</i></span> + <span class=\"tex-span\">0·<i>t</i></span> + <span class=\"tex-span\">0·1</span>.</p><p><span class=\"tex-span\"><i>y</i></span> = <span class=\"tex-span\">1·<i>x</i></span> + <span class=\"tex-span\">2·<i>y</i></span> + <span class=\"tex-span\">0·<i>dx</i></span> + <span class=\"tex-span\">1·<i>dy</i></span> + <span class=\"tex-span\">0·<i>t</i></span> + <span class=\"tex-span\">0·1</span>.</p><p><span class=\"tex-span\"><i>dx</i></span> = <span class=\"tex-span\">1·<i>x</i></span> + <span class=\"tex-span\">1·<i>y</i></span> + <span class=\"tex-span\">1·<i>dx</i></span> + <span class=\"tex-span\">0·<i>dy</i></span> + <span class=\"tex-span\">1·<i>t</i></span> + <span class=\"tex-span\">2·1</span>.</p><p><span class=\"tex-span\"><i>dy</i></span> = <span class=\"tex-span\">1·<i>x</i></span> + <span class=\"tex-span\">1·<i>y</i></span> + <span class=\"tex-span\">0·<i>dx</i></span> + <span class=\"tex-span\">1·<i>dy</i></span> + <span class=\"tex-span\">1·<i>t</i></span> + <span class=\"tex-span\">2·1</span>.</p><p><span class=\"tex-span\"><i>t</i></span> = <span class=\"tex-span\">0·<i>x</i></span> + <span class=\"tex-span\">0·<i>y</i></span> + <span class=\"tex-span\">0·<i>dx</i></span> + <span class=\"tex-span\">0·<i>dy</i></span> + <span class=\"tex-span\">1·<i>t</i></span> + <span class=\"tex-span\">1·1</span>.</p><p><span class=\"tex-span\">1</span> = <span class=\"tex-span\">0·<i>x</i></span> + <span class=\"tex-span\">0·<i>y</i></span> + <span class=\"tex-span\">0·<i>dx</i></span> + <span class=\"tex-span\">0·<i>dy</i></span> + <span class=\"tex-span\">0·<i>t</i></span> + <span class=\"tex-span\">1·1</span>.</p><p>So if we calculate <span class=\"tex-span\"><i>t</i> - 1</span> power of <span class=\"tex-span\"><i>base</i></span> and then multiply <span class=\"tex-span\">(<i>sx</i>, <i>sy</i>, <i>dx</i>, <i>dy</i>, <i>t</i>, 1)</span> by it we will calculate parameters at moment <span class=\"tex-span\"><i>t</i></span>.</p><p>Power of matrix can be calculated via binary power modulo algo due to associativity of matrix multiplication. More info at <a href=\"http://e-maxx.ru/algo/binary_pow\">http://e-maxx.ru/algo/binary_pow</a></p><p>Using trivial matrix multiplication algo we will solve this task in time proportional <span class=\"tex-span\">6<sup class=\"upper-index\">3</sup>·<i>log</i>(<i>t</i>)</span>.</p></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/385\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 226 (Div. 2)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-2930-10569\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"2930\",\n blogEntryId: \"10514\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-10569\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+85</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-10569\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/CleRIC\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/CleRIC\">\n CleRIC\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Jan/23/2014 19:33\">10 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/10514#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/10514#comments\">\n 30\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"10585\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (25)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"158988\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/OpalDshawn\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/40047/avatar/c26edf07c13c133a.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/OpalDshawn\" title=\"Master OpalDshawn\" class=\"rated-user user-orange\">OpalDshawn</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2014 22:59\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-158988\" href=\"?#comment-158988\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"158988\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"158988\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"40047\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-158988\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Great Editorial!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-158988 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-158988 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-158988\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159026\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Xellos\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/69675/avatar/8526bcfc8e687b43.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/Xellos\" title=\"International Grandmaster Xellos\" class=\"rated-user user-red\">Xellos</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/25/2014 02:06\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159026\" href=\"?#comment-159026\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"159026\" revisionCount=\"7\" revision=\"7\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">7</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"159026\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"28\"\r\n data-commentUserId=\"69675\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+28</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159026\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I solved E (theoretically, I don't really want to implement it) by solving the system of equations:</p> <center><span class=\"tex-span\"><i>x</i>(<i>t</i>) = [<i>x</i>(<i>t</i> - 1) + <i>v</i><sub class=\"lower-index\"><i>x</i></sub>(<i>t</i>) - 1]%<i>N</i> + 1</span></center> <center><span class=\"tex-span\"><i>y</i>(<i>t</i>) = [<i>y</i>(<i>t</i> - 1) + <i>v</i><sub class=\"lower-index\"><i>y</i></sub>(<i>t</i>) - 1]%<i>N</i> + 1</span></center> <center><span class=\"tex-span\"><i>v</i><sub class=\"lower-index\"><i>x</i></sub>(<i>t</i>) = <i>v</i><sub class=\"lower-index\"><i>x</i></sub>(<i>t</i> - 1) + <i>t</i> - 1 + <i>x</i>(<i>t</i> - 1) + <i>y</i>(<i>t</i> - 1)</span></center> <center><span class=\"tex-span\"><i>v</i><sub class=\"lower-index\"><i>y</i></sub>(<i>t</i>) = <i>v</i><sub class=\"lower-index\"><i>y</i></sub>(<i>t</i> - 1) + <i>t</i> - 1 + <i>x</i>(<i>t</i> - 1) + <i>y</i>(<i>t</i> - 1)</span></center><p>for $t > 0$, where the values of <span class=\"tex-span\">(<i>x</i>, <i>y</i>, <i>v</i><sub class=\"lower-index\"><i>x</i></sub>, <i>v</i><sub class=\"lower-index\"><i>y</i></sub>)(0)</span> are given as input parameters, and the time is 0-based.</p><p>Firstly, we want to get rid of the modulo function. We can't just compute all variables modulo <span class=\"tex-span\"><i>N</i></span>, because there's the -1, so we'll shift the coordinates to <span class=\"tex-span\">(<i>x</i>', <i>y</i>')(<i>t</i>)</span>, where <span class=\"tex-span\"><i>x</i>' = <i>x</i> - 1</span>, <span class=\"tex-span\"><i>y</i>' = <i>y</i> - 1</span>. Now the equations become</p> <center><span class=\"tex-span\"><i>x</i>'(<i>t</i>) = <i>x</i>'(<i>t</i> - 1) + <i>v</i><sub class=\"lower-index\"><i>x</i></sub>(<i>t</i>)</span></center> <center><span class=\"tex-span\"><i>y</i>'(<i>t</i>) = <i>y</i>'(<i>t</i> - 1) + <i>v</i><sub class=\"lower-index\"><i>y</i></sub>(<i>t</i>)</span></center> <center><span class=\"tex-span\"><i>v</i><sub class=\"lower-index\"><i>x</i></sub>(<i>t</i>) = <i>v</i><sub class=\"lower-index\"><i>x</i></sub>(<i>t</i> - 1) + <i>t</i> + 1 + <i>x</i>'(<i>t</i> - 1) + <i>y</i>'(<i>t</i> - 1)</span></center> <center><span class=\"tex-span\"><i>v</i><sub class=\"lower-index\"><i>y</i></sub>(<i>t</i>) = <i>v</i><sub class=\"lower-index\"><i>y</i></sub>(<i>t</i> - 1) + <i>t</i> + 1 + <i>x</i>'(<i>t</i> - 1) + <i>y</i>'(<i>t</i> - 1)</span></center><p>where all variables are computed modulo $N$ (we'll omit that from now on). We can compute <span class=\"tex-span\">(<i>x</i>, <i>y</i>, <i>v</i><sub class=\"lower-index\"><i>x</i></sub>, <i>v</i><sub class=\"lower-index\"><i>y</i></sub>)(1)</span> from this, and further substitute for <span class=\"tex-span\"><i>v</i><sub class=\"lower-index\"><i>x</i></sub>, <i>v</i><sub class=\"lower-index\"><i>y</i></sub></span>, which gives for <span class=\"tex-span\"><i>t</i> > 1</span></p> <center><span class=\"tex-span\"><i>x</i>'(<i>t</i>) - <i>x</i>'(<i>t</i> - 1) = <i>x</i>'(<i>t</i> - 1) - <i>x</i>'(<i>t</i> - 2) + <i>t</i> + 1 + <i>x</i>'(<i>t</i> - 1) + <i>y</i>'(<i>t</i> - 1)</span></center> <center><span class=\"tex-span\"><i>y</i>'(<i>t</i>) - <i>y</i>'(<i>t</i> - 1) = <i>y</i>'(<i>t</i> - 1) - <i>y</i>'(<i>t</i> - 2) + <i>t</i> + 1 + <i>x</i>'(<i>t</i> - 1) + <i>y</i>'(<i>t</i> - 1)</span></center><p>Let's now define</p> <center><span class=\"tex-span\"><i>s</i>(<i>t</i>) = <i>x</i>'(<i>t</i>) + <i>y</i>'(<i>t</i>)</span></center> <center><span class=\"tex-span\"><i>d</i>(<i>t</i>) = <i>x</i>'(<i>t</i>) - <i>y</i>'(<i>t</i>)</span></center><p>using which we can rewrite the sum and difference of the equations above to</p> <center><span class=\"tex-span\"><i>d</i>(<i>t</i>) - <i>d</i>(<i>t</i> - 1) = <i>d</i>(<i>t</i> - 1) - <i>d</i>(<i>t</i> - 2)</span></center> <center><span class=\"tex-span\"><i>s</i>(<i>t</i>) - <i>s</i>(<i>t</i> - 1) = <i>s</i>(<i>t</i> - 1) - <i>s</i>(<i>t</i> - 2) + 2(<i>t</i> + 1) + 2<i>s</i>(<i>t</i> - 1)</span></center><p>Once again, we define $q(t)=s(t)+t+2$ (actually, it's <span class=\"tex-span\"><i>s</i>(<i>t</i>) + <i>t</i> + <i>c</i></span>, and we compute the constant <span class=\"tex-span\"><i>c</i></span> by substituting and trying to get the constant term to 0), and rewrite our equations to</p> <center><span class=\"tex-span\"><i>d</i>(<i>t</i>) = 2<i>d</i>(<i>t</i> - 1) - <i>d</i>(<i>t</i> - 2)</span></center> <center><span class=\"tex-span\"><i>q</i>(<i>t</i>) = 4<i>q</i>(<i>t</i> - 1) - <i>q</i>(<i>t</i> - 2)</span></center><p>which can be solved explicitly (I'm lazy, so I'm just using Wolfram Alpha, read more about linear recurrent equations on Wikipedia or something):</p> <center><img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/5ec2a1c8cb9dd5c6d22e9c89f85ea721c45a9659.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></center> <center><span class=\"tex-span\"><i>d</i>(<i>t</i>) = <i>C</i> * <i>t</i> + <i>D</i></span></center><p>where the parameters $A..D$ are given by the values for <span class=\"tex-span\"><i>t</i> ≤ 1</span>.</p><p>This is more of a theoretical solution (since as long as we get the recurrences for <span class=\"tex-span\"><i>d</i>(<i>t</i>)</span> and <span class=\"tex-span\"><i>q</i>(<i>t</i>)</span>, it's best to use matrix multiplication), but I just wanted to do it this way :D</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159026 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159026 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159026\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159027\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/bilalyasar\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/88216/avatar/25c063de47c0f66a.jpg'/> </a>\n <div><a href=\"/profile/bilalyasar\" title=\"Expert bilalyasar\" class=\"rated-user user-blue\">bilalyasar</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/25/2014 03:59\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159027\" href=\"?#comment-159027\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"159027\" revisionCount=\"23\" revision=\"23\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">23</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"159027\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"88216\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159027\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>i think the matrix should be that: {2,1,1,1,0,0},</p><p>{1,2,1,1,0,0},</p><p>{1,0,1,0,0,0},</p><p>{0,1,0,1,0,0},</p><p>{0,0,1,1,1,0},</p><p>{0,0,0,0,1,1} };</p><p>i tried and solved it. with this matrix.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159027 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159027 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159027\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159144\" commentParentId=\"159027\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Amir.bh\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/29435/avatar/84331c66da301d6d.jpg'/> </a>\n <div><a href=\"/profile/Amir.bh\" title=\"Candidate Master Amir.bh\" class=\"rated-user user-violet\">Amir.bh</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/26/2014 15:32\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159144\" href=\"?#comment-159144\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159027\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159144\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"29435\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159144\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Rev. 23????! How could this happen?! :D</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159144 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159144 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159144\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159162\" commentParentId=\"159144\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Xellos\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/69675/avatar/8526bcfc8e687b43.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/Xellos\" title=\"International Grandmaster Xellos\" class=\"rated-user user-red\">Xellos</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/26/2014 17:13\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159162\" href=\"?#comment-159162\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159144\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159162\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"69675\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159162\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Maybe for the same reason as rev.7 of my comment above — I edit my comment, click "Save", nothing happens; I wait until my internet connection is stronger, click again, and nothing happens again, etc., until I lose patience and reload the page. And look what happened: the revisions were counted, but my comment wasn't edited. Some bug of CF, maybe.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159162 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159162 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159162\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159054\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/llaki\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/24382/avatar/6683eebf7eea08ec.jpg'/> </a>\n <div><a href=\"/profile/llaki\" title=\"Expert llaki\" class=\"rated-user user-blue\">llaki</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/25/2014 15:18\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159054\" href=\"?#comment-159054\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159054\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"24382\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159054\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Nice editorial. Anyways, I had a sense that explanation of problem E does not give you an idea of how you can come up with that solution. Let me clarify that: The state can be described by following variables: x — where is the bear currently (x-coordinate); y — where is the bear currently (y-coordinate); dx — the current speed towards X axis; dy — the current speed towards Y axis; t — time passed after the start;</p><p>This information is enough to describe a state. Now let's see how the state changes: (dx)' = dx + (x+y+t), (dy)' = dy+(x+y+t), (x)' = x + (dx)' = 2x+y+dx+t, (y)'=x+2y+dy+t, (t)'= t+1.</p><p>As we see, the new state is similar to linear combination of previous state components, except for t=t+1 (1 is not in a state). It is very similar to matrix multiplication, except for we don't have 1. So we can make a matrix this way: Let's say the state is (1x6) matrix : (x, y, dx, dy, t, 1) and the matrix (M) is 100001 021110 012110 010100 001010 011111 It's easy to see why the new state is the old state matrix multiplied by M. The rest is easy, our final state is going to be the initial state matrix multiplied by the T-th power of M. Of course we're gonna use the fast exponentiation. (The naive multiplication is fine here, because the sizes are too small)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159054 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159054 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159054\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159061\" commentParentId=\"159054\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/KKpoker\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/120167/avatar/297c9d6f6c6672be.jpg'/> </a>\n <div><a href=\"/profile/KKpoker\" title=\"Specialist KKpoker\" class=\"rated-user user-cyan\">KKpoker</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/25/2014 16:34\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159061\" href=\"?#comment-159061\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159054\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"159061\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"159061\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"4\"\r\n data-commentUserId=\"120167\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+4</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159061\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>thx a lot ~ during the exam i think the raspberry will be eaten all , then the number will change from x+y-->1 a silly misunderstanding T_T</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159061 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159061 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159061\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"372356\" commentParentId=\"159054\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/nguyenit67\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/509284/avatar/98668c3aa6c04ca6.jpg'/> </a>\n <div><a href=\"/profile/nguyenit67\" title=\"Pupil nguyenit67\" class=\"rated-user user-green\">nguyenit67</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/11/2017 14:02\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-372356\" href=\"?#comment-372356\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159054\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"372356\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"509284\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-372356\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I'm sorry :) but I don't see why (x)'= x+(dx)'? Could u explain that to me?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-372356 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-372356 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-372356\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"372645\" commentParentId=\"372356\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/nguyenit67\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/509284/avatar/98668c3aa6c04ca6.jpg'/> </a>\n <div><a href=\"/profile/nguyenit67\" title=\"Pupil nguyenit67\" class=\"rated-user user-green\">nguyenit67</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/12/2017 08:25\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-372645\" href=\"?#comment-372645\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-372356\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"372645\" revisionCount=\"4\" revision=\"4\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">4</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"372645\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"509284\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-372645\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Ah</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-372645 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-372645 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-372645\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"372646\" commentParentId=\"159054\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/nguyenit67\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/509284/avatar/98668c3aa6c04ca6.jpg'/> </a>\n <div><a href=\"/profile/nguyenit67\" title=\"Pupil nguyenit67\" class=\"rated-user user-green\">nguyenit67</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/12/2017 08:26\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-372646\" href=\"?#comment-372646\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159054\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"372646\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"509284\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-372646\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Ah now I see it. Thank you for your explanation :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-372646 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-372646 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-372646\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159079\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/MoustafaMaher\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/47658/avatar/48ad52ec2bf89c75.jpg'/> </a>\n <div><a href=\"/profile/MoustafaMaher\" title=\"Candidate Master MoustafaMaher\" class=\"rated-user user-violet\">MoustafaMaher</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/25/2014 19:18\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159079\" href=\"?#comment-159079\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159079\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"47658\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159079\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Problem D !?! </p><p>how u can calculate calc_rightmost_lighted_point() in ur Dp without keeping the last right_most_point u can get till before this state </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159079 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159079 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159079\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159093\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Lord_F\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/41018/avatar/1e2b817ca83c107e.jpg'/> </a>\n <div><a href=\"/profile/Lord_F\" title=\"Candidate Master Lord_F\" class=\"rated-user user-violet\">Lord_F</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/25/2014 21:37\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159093\" href=\"?#comment-159093\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"159093\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"159093\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"41018\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159093\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>By the way, in problem D you can use law of sines to find the distance that is lighted with some floodlight.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159093 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159093 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159093\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159105\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/-emli-\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/29285/avatar/9fa3a36fa8f9d060.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/-emli-\" title=\"Pupil -emli-\" class=\"rated-user user-green\">-emli-</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/25/2014 23:59\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159105\" href=\"?#comment-159105\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159105\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"29285\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159105\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In problem C , i can't understand why we add pre[i-1] to pre[i]?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159105 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159105 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159105\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159109\" commentParentId=\"159105\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/piotreekw\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/piotreekw\" title=\"Specialist piotreekw\" class=\"rated-user user-cyan\">piotreekw</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/26/2014 00:51\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159109\" href=\"?#comment-159109\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159105\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159109\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"151924\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159109\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>If you iterate i from 2 to n-1 adding pre[i-1] to pre[i], every new pre[i] will contain sum of all pre from 1 to i</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159109 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159109 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159109\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159126\" commentParentId=\"159109\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/-emli-\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/29285/avatar/9fa3a36fa8f9d060.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/-emli-\" title=\"Pupil -emli-\" class=\"rated-user user-green\">-emli-</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/26/2014 09:24\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159126\" href=\"?#comment-159126\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159109\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159126\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"29285\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159126\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thank you! one more question how to prove that pre[r]-pre[l-1] is answer of query?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159126 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159126 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159126\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159129\" commentParentId=\"159126\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ReekinAcer\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/ReekinAcer\" title=\"Expert ReekinAcer\" class=\"rated-user user-blue\">ReekinAcer</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/26/2014 12:01\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159129\" href=\"?#comment-159129\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159126\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159129\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"106426\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159129\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I think it is clearer if we denote Cnt[i] = f(i) and Sum[i] = Cnt[1] + Cnt[2] + ... + Cnt[i]. Now, the answer for a query on [l, r] is Sum[r]-Sum[l-1].</p><p>Sum[r]-Sum[l-1] = (Cnt[1] + Cnt[2] + ... + Cnt[r])-(Cnt[1] + Cnt[2] + ... + Cnt[l-1]) = [(Cnt[1] + ... + Cnt[l-1]) + (Cnt[l] + Cnt[l + 1] + ... + Cnt[r])] — (Cnt[1] + ... + Cnt[l-1]) = Cnt[l] + Cnt[l + 1] + ... + Cnt[r].</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159129 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159129 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159129\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"211346\" commentParentId=\"159105\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/G_Hani\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/119692/avatar/ea9b44051a710c1b.jpg'/> </a>\n <div><a href=\"/profile/G_Hani\" title=\"Specialist G_Hani\" class=\"rated-user user-cyan\">G_Hani</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/06/2015 00:49\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-211346\" href=\"?#comment-211346\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159105\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"211346\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"119692\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-211346\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p><a class=\"rated-user user-green\" href=\"/profile/-emli-\" title=\"Pupil -emli-\">-emli-</a> <a class=\"rated-user user-blue\" href=\"/profile/ReekinAcer\" title=\"Expert ReekinAcer\">ReekinAcer</a> can u help me please. here my code for C and get WA at tc 4 !! <a href=\"/contest/385/submission/9731769\" title=\"Submission 9731769 by G_Hani\">9731769</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-211346 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-211346 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-211346\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159138\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/shubh09\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/shubh09\" title=\"Expert shubh09\" class=\"rated-user user-blue\">shubh09</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/26/2014 13:36\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159138\" href=\"?#comment-159138\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159138\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"72364\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159138\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Nice editorial! But I suppose that a link to a solution implementing the idea outlined in the editorial for every question would help us understand them even better!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159138 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159138 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159138\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159141\" commentParentId=\"159138\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Lord_F\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/41018/avatar/1e2b817ca83c107e.jpg'/> </a>\n <div><a href=\"/profile/Lord_F\" title=\"Candidate Master Lord_F\" class=\"rated-user user-violet\">Lord_F</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/26/2014 14:13\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159141\" href=\"?#comment-159141\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159138\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"159141\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"159141\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"41018\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159141\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Well, you can use "Status filter"</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159141 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159141 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159141\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159178\" commentParentId=\"159141\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/shubh09\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/shubh09\" title=\"Expert shubh09\" class=\"rated-user user-blue\">shubh09</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/26/2014 18:14\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159178\" href=\"?#comment-159178\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159141\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159178\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"72364\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159178\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Well, not all the accepted solutions use the idea mentioned in the editorials. It's a bit inconvenient browsing through all accepted solutions to find the one which does.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159178 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159178 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159178\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"330629\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/adityagupta1089\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/337877/avatar/e2156094910d501.jpg'/> </a>\n <div><a href=\"/profile/adityagupta1089\" title=\"Expert adityagupta1089\" class=\"rated-user user-blue\">adityagupta1089</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Dec/14/2016 22:58\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-330629\" href=\"?#comment-330629\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"330629\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"330629\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"337877\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-330629\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In problem C, I did made a cnt array (or say a hashmap) and did find all primes below the maximum x using Sieve of Erathosthenes, then for each prime I iterated over every number and and found f(p) and stored them in a Binary Index Tree, but that didn't help. I believe my complexity is O(n(logn)(loglogn)+m(logn+logP)+PlogP) where P(664,579~10^7) is the count of primes below maximum x so total operations are around 5e6+6e7+4e7 but it has a TLE?.<a href=\"//codeforces.com/contest/385/submission/22981801\">This</a> is my submission.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-330629 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-330629 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-330629\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"587392\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/reet_bhaati\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1176149/avatar/7f68facc9bda856e.jpg'/> </a>\n <div><a href=\"/profile/reet_bhaati\" title=\"Specialist reet_bhaati\" class=\"rated-user user-cyan\">reet_bhaati</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/10/2020 10:46\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-587392\" href=\"?#comment-587392\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"587392\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"-8\"\r\n data-commentUserId=\"1176149\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-587392\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>can anyone help me out? I have tried 385C and it gives me a runtime error on test case 4 link to my code — <a href=\"https://ideone.com/fork/GMagWh\">https://ideone.com/fork/GMagWh</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-587392 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-587392 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-587392\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"642670\" commentParentId=\"587392\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/back_to_code\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1292092/avatar/b57b403a9af2ef26.jpg'/> </a>\n <div><a href=\"/profile/back_to_code\" title=\"Specialist back_to_code\" class=\"rated-user user-cyan\">back_to_code</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/15/2020 21:38\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-642670\" href=\"?#comment-642670\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-587392\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"642670\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"642670\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1292092\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-642670\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I don't know if you are still looking for this :</p><p>That might be because x or y i.e the query ranges might be going out of limits. Also it may help the others who attempt it.</p><p>Edit : Also if anyone is getting TLE even after implementing same approach use:</p> <pre><code>ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);\n</code></pre></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-642670 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-642670 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-642670\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"658423\" commentParentId=\"587392\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/apoorva222g\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1213778/avatar/2153e9cce1fd37f.jpg'/> </a>\n <div><a href=\"/profile/apoorva222g\" title=\"Expert apoorva222g\" class=\"rated-user user-blue\">apoorva222g</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/09/2020 11:58\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-658423\" href=\"?#comment-658423\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-587392\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"658423\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1213778\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-658423\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Reduce any l or r to 10^7 if it is greater than 10^7. Try this case 1 2000 1 1424767024 1629755604</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-658423 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-658423 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-658423\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"686007\" commentParentId=\"658423\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/y0g38h_kum4r\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1561883/avatar/5594dfbdb87a226d.jpg'/> </a>\n <div><a href=\"/profile/y0g38h_kum4r\" title=\"Expert y0g38h_kum4r\" class=\"rated-user user-blue\">y0g38h_kum4r</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/25/2020 02:40\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-686007\" href=\"?#comment-686007\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-658423\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"686007\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1561883\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-686007\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>OH! thanks a lot for this test case!!!!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-686007 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-686007 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-686007\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n <br/>\r\n\r\n<div id=\"editBox-10585\" style=\"width:50em;display:none;\">\r\n <div class=\"previewBody\" style=\"border: 1px solid #d4d4d4; margin-bottom: 0.5em; padding: 0.25em; display:none;\"> </div>\r\n <div style=\"width: 1px\"> </div>\r\n <div class=\"commentLocale\" style=\"position: relative; top: 0.5em;left:4px;display: none;\">\r\n <input type=\"radio\" name=\"locale\" value=\"en\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In English</span>\r\n <input style=\"margin-left:1em\" type=\"radio\" name=\"locale\" value=\"ru\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In Russian</span>\r\n </div>\r\n <textarea data-drafts-id=\"CommentReplyFrame\" class=\"wysiwyg\" name=\"editContent\" rows=\"20\" style=\"width:99%;\"></textarea>\r\n <div class=\"error error__content\"></div>\r\n <div style=\"text-align:center;\">\r\n <input type=\"button\" name=\"preview\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Preview\"/>\r\n <input type=\"button\" name=\"save\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Save\"/>\r\n </div>\r\n</div>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n\r\nvar firstPreview10585 = true;\r\nvar lastPreviewContent10585 = '';\r\n\r\nif (!window.moveCommentRevision) {\r\n moveCommentRevision = function(e, dir) {\r\n var p = e.parent();\r\n var revisionCount = parseInt(p.attr(\"revisionCount\"));\r\n var revision = parseInt(p.attr(\"revision\"));\r\n var next = revision + dir;\r\n var commentId = p.attr(\"commentId\");\r\n if (next >= 1 && next <= revisionCount) {\r\n $.post(\r\n \"/data/comment-data\",\r\n {action: \"revision\", commentId: commentId, revision: next},\r\n function(json) {\r\n if (json.success == \"true\") {\r\n var parentDiv = e;\r\n\r\n while (parentDiv !== null && (parentDiv[0].nodeName.toLowerCase() !== \"td\" || !parentDiv.hasClass(\"right\"))) {\r\n parentDiv = parentDiv.parent();\r\n }\r\n\r\n if (parentDiv === null) {\r\n return;\r\n }\r\n\r\n parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\").html(json.content);\r\n Codeforces.setupSpoilers(parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\"));\r\n p.attr(\"revision\", next);\r\n p.find(\"span.revision\").text(next);\r\n if (next == 1) {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"visible\");\r\n }\r\n if (next == revisionCount) {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"visible\");\r\n }\r\n\r\n window.updateTypography();\r\n MathJax.Hub.Typeset();\r\n } else {\r\n alert(e.error);\r\n }\r\n },\r\n \"json\"\r\n );\r\n }\r\n };\r\n}\r\n\r\n$(\"div[commentableId=10585] a.leftRevision\").click(function () {\r\n window.moveCommentRevision($(this), -1);\r\n return false;\r\n});\r\n\r\n$(\"div[commentableId=10585] a.rightRevision\").click(function () {\r\n window.moveCommentRevision($(this), +1);\r\n return false;\r\n});\r\n\r\n\r\n\r\n });\n </script>\n\r\n\r\n <script src=\"//codeforces.org/s/81027/js/swfobject-2.2.min.js\" type=\"text/javascript\"></script>\n <script src=\"//codeforces.org/s/81027/js/ftaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n if (window.evercookie) {\n var ec = new evercookie({\n history: false,\n silverlight: false,\n baseurl: '',\n asseturi: '/assets',\n phpuri: '/2fdcd78',\n pngPath: '/eps',\n etagPath: '/ees',\n cachePath: '/ecs'\n });\n\n var randomNumber = function () {\n return Math.random().toString(36).substr(2);\n };\n\n var randomToken = function () {\n return (randomNumber() + randomNumber()).substring(0, 18);\n };\n\n window._ftaa = \"\";\n\n ec.get(\"70a7c28f3de\", function (value) {\n window._ftaa = value;\n if (!window._ftaa) {\n window._ftaa = randomToken();\n ec.set(\"70a7c28f3de\", window._ftaa);\n }\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n } else {\n window._ftaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\n <script src=\"//codeforces.org/s/81027/js/bfaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n var fpCallback = function() {\n Fingerprint2.get({}, function(components) {\n window._bfaa = Fingerprint2.x64hash128(components.map(function (pair) { return pair.value }).join(), 31);\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n };\n if (typeof Fingerprint2 !== 'undefined') {\n if (window.requestIdleCallback) {\n requestIdleCallback(fpCallback)\n } else {\n setTimeout(fpCallback, 500)\n }\n } else {\n window._bfaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"a.new-root-comment\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n\r\n $(\".comment-table .reply a\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".vote-for-comment\").mouseover(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").mouseout(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").click(function () {\r\n var vote = $(this);\r\n var commentId = $(this).parent().attr(\"commentid\");\r\n var commentRating = $(this).parent().attr(\"data-commentRating\");\r\n var direction = $(this).attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n $.post(\"/data/comment/vote\", {commentId: commentId, _tta: Codeforces.tta(), vote: direction, commentRating: commentRating}, function(data) {\r\n if (direction != 0 && !ownComment && data[\"success\"] == \"true\") {\r\n vote.parent().find(\".vote-for-comment\").attr(\"voteDirection\", 0);\r\n if (direction == 1)\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n else {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.closest(\".CommentVoteFrame\").find(\".ComplaintFrame\").css(\"display\", \"inline-block\");\r\n }\r\n vote.find(\"img\").attr(\"popacity\", \"1.0\");\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n vote.parent().find(\".commentRating\").html(data[\"commentRating\"]);\r\n }\r\n Codeforces.showMessage(data[\"message\"]);\r\n }, \"json\");\r\n return false;\r\n });\r\n\r\n $(\".negative-comment-vote\").closest(\".comment-table\").addClass(\"comment-bad\");\r\n\r\n $(\".troll-comment-vote\").closest(\".comment\").css(\"display\", \"none\");\r\n\r\n $(\".too-negative-comment-vote\").closest(\".comment-table\").each(function () {\r\n var e = $(this);\r\n e.addClass(\"comment-too-bad\");\r\n var commentId = e.attr(\"commentId\");\r\n $(\"<div class='bad-comment-replacement ttypography'>The comment is hidden because of too negative feedback, click <a href=# class=show-bad-comment-link>here</a> to view it</div>\").appendTo(\r\n e.find(\".right\")\r\n );\r\n e.find(\".comment-content\").hide();\r\n e.find(\".show-bad-comment-link\").click(function () {\r\n e.find(\".comment-content\").show();\r\n e.find(\".bad-comment-replacement\").hide();\r\n return false;\r\n });\r\n });\r\n });\n </script>\n </div>\r\n\r\n <style type=\"text/css\">\r\n .new-comments-box {\r\n padding: 0.5em;\r\n width: 22px;\r\n font-size: 1.3rem;\r\n font-weight: bold !important;\r\n\r\n position: fixed;\r\n top: 40%;\r\n right: 0;\r\n opacity: 0.2;\r\n color: white;\r\n text-align: center;\r\n\r\n border: 1px solid #222;\r\n background-color: #888 !important;\r\n border-radius: 3px;\r\n -moz-border-radius: 3px;\r\n -webkit-border-radius: 3px;\r\n }\r\n\r\n .new-comments-box:hover {\r\n opacity: 1;\r\n }\r\n\r\n .new-comments-box .dir:hover {\r\n background: #3B5998 !important;\r\n cursor: pointer;\r\n }\r\n </style>\r\n\r\n <div class=\"new-comments-box\" data-position=\"outside\" data-index=\"-1\" style=\"display: none;\">\r\n <div class=\"up dir\" title=\"Ctrl+Up\">↑<hr/>\r\n </div>\r\n <div class=\"info\" title=\"New comments\"></div>\r\n <div class=\"down dir\" title=\"Ctrl+Down\">\r\n <hr/>↓\r\n </div>\r\n </div>\r\n\r\n <script>\r\n $(\".show-archived-checkbox\").change(function () {\r\n const checked = $(this).is(\":checked\");\r\n $.post(\"/data/comment-data\", {action: \"setShowArchived\", checked}, function (json) {\r\n if (json[\"success\"] !== \"true\") {\r\n alert(json[\"error\"]);\r\n } else {\r\n if (checked) {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are now displayed\")\r\n } else {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are no longer displayed\")\r\n }\r\n }\r\n });\r\n return false;\r\n });\r\n\r\n function gotoComment(direction) {\r\n var box = $(\".new-comments-box\");\r\n var index = parseInt(box.attr(\"data-index\"));\r\n if (index == -1)\r\n index = 0;\r\n else\r\n index = Math.max(0, Math.min(parseInt(box.find(\".info\").text()) - 1, index + direction));\r\n box.attr(\"data-index\", index);\r\n var comment = $($(\".comment .highlight-blue[commentId]\").get(index));\r\n $('html, body').animate({\r\n 'scrollTop': Math.max(0, comment.offset().top - ($(window).height() - comment.height()) / 2)\r\n });\r\n return false;\r\n }\r\n\r\n $(\".new-comments-box .down\").click(function () {\r\n return gotoComment(1);\r\n });\r\n\r\n $(\".new-comments-box .up\").click(function () {\r\n return gotoComment(-1);\r\n });\r\n\r\n $(document).keydown(function (e) {\r\n var code = (e.keyCode ? e.keyCode : e.which);\r\n if (e.ctrlKey) {\r\n if (code == 38 || code == 40) {\r\n gotoComment(code - 39);\r\n }\r\n }\r\n });\r\n\r\n var newCommentCount = $(\".comment .highlight-blue[commentId]\").length;\r\n if (newCommentCount > 0) {\r\n $(\".new-comments-box .info\").text(newCommentCount);\r\n $(\".new-comments-box\").show();\r\n }\r\n\r\n $('table.comment-table').mouseenter(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").addClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n\r\n $('table.comment-table').mouseleave(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").removeClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n </script>\r\n\r\n\r\n\r\n <script>\r\n function adjustTopicComplainFrames() {\r\n let topicIds = [];\r\n\r\n $(\".has-topic-id\").each(function () {\r\n const $this = $(this);\r\n const topicId = $this.attr(\"topicId\");\r\n if (topicId) {\r\n topicIds.push(topicId);\r\n }\r\n });\r\n\r\n $.post(\"/data/topics\", {\r\n action: \"findComplainableTopicIds\",\r\n topicIds: topicIds.join(\",\")\r\n }, function (json) {\r\n if (json[\"success\"] === \"true\") {\r\n for (const topicId of json[\"complainableTopicIds\"].split(\",\")) {\r\n $(\".has-topic-id[topicId=\" + topicId + \"]\").each(function () {\r\n $(this).find(\".meta .ComplaintFrame\").css(\"display\", \"inline-block\");\r\n });\r\n }\r\n }\r\n }, \"json\");\r\n }\r\n\r\n $(function () {\r\n adjustTopicComplainFrames();\r\n })\r\n </script>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-10569\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 10569, _tta: Codeforces.tta(), topicRevisionId: 36378, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-10569\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 10569, _tta: Codeforces.tta(), topicRevisionId: 36378, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n </div>\r\n </div>\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 22:13:04</span> (h1).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/81027/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/81027/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/81027/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/81027/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-81027.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'8128758f5b7075a7',t:'MTY5NjcwNTk4NC4yOTcwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"}}},{"rowIdx":1949,"cells":{"problem_id":{"kind":"string","value":"386A"},"contest":{"kind":"string","value":"386"},"problem":{"kind":"string","value":"A"},"lang":{"kind":"string","value":"en"},"problem_title":{"kind":"string","value":"A. Second-Price Auction"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">A. Second-Price Auction</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>In this problem we consider a special type of an auction, which is called the second-price auction. As in regular auction <span class=\"tex-span\"><i>n</i></span> bidders place a bid which is price a bidder ready to pay. The auction is closed, that is, each bidder secretly informs the organizer of the auction price he is willing to pay. After that, the auction winner is the participant who offered the highest price. However, he pay not the price he offers, but the highest price among the offers of other participants (hence the name: the second-price auction).</p><p>Write a program that reads prices offered by bidders and finds the winner and the price he will pay. Consider that all of the offered prices are different.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line of the input contains <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">2 ≤ <i>n</i> ≤ 1000</span>) — number of bidders. The second line contains <span class=\"tex-span\"><i>n</i></span> distinct integer numbers <span class=\"tex-span\"><i>p</i><sub class=\"lower-index\">1</sub>, <i>p</i><sub class=\"lower-index\">2</sub>, ... <i>p</i><sub class=\"lower-index\"><i>n</i></sub></span>, separated by single spaces (<span class=\"tex-span\">1 ≤ <i>p</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 10000</span>), where <span class=\"tex-span\"><i>p</i><sub class=\"lower-index\"><i>i</i></sub></span> stands for the price offered by the <span class=\"tex-span\"><i>i</i></span>-th bidder.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>The single output line should contain two integers: index of the winner and the price he will pay. Indices are 1-based.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>2<br/>5 7<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>2 5<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3<br/>10 2 8<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1 8<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>6<br/>3 8 2 9 4 14<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>6 9<br/></pre></div></div></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"e142b1496b4919b3b6a82917f5b7e4d4\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - A - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"44c637d2380d90080d2a194660db8ac80257ad59\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - A - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/73366/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/73366/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/73366/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/73366/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/73366/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/73366/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/73366/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/73366/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/73366/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/73366/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/73366/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/73366/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/73366/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/73366/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/sidebar-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/a037fe51637846d9c7c725713cd840ea/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='e142b1496b4919b3b6a82917f5b7e4d4'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/73366/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/73366/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fcontest%2F386%2Fproblem%2FA%3Flocale%3Den\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"current\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='e142b1496b4919b3b6a82917f5b7e4d4'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:100%;\"><a style=\"color: black\" href=\"/contest/386\">Testing Round 9</a></th>\n </tr>\n <tr>\n <td class=\"left bottom\" colspan=\"1\"><span class=\"contest-state-phase\">Finished</span></td>\n </tr>\n </tbody>\n </table>\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Practice?\n <div class=\"top-links\">\n </div>\n </div>\n<div>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Want to solve the contest problems after the official contest ends? Just register for practice and you will be able to submit solutions.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"\" method=\"post\"><input type='hidden' name='csrf_token' value='e142b1496b4919b3b6a82917f5b7e4d4'/>\r\n <input type=\"hidden\" name=\"action\" value=\"registerForPractice\"/>\r\n <input type=\"submit\" name=\"submit\" value=\"Register for practice\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div> \r\n</div>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox ContestVirtualFrame borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Virtual participation <i class=\"sidebar-caption-icon las la-angle-down\"></i>\r\n\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\" \"\r\n\r\n data-page-url=\"/data/sidebarFrames\"\r\n\r\n>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests.\n\nIf you've seen these problems, a virtual contest is not for you - solve these problems in the archive.\n\nIf you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.\n\nNever use someone else's code, read the tutorials or communicate with other person during a virtual contest.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"/contest/386/virtual\" method=\"get\">\r\n <input type=\"submit\" name=\"submit\" value=\"Start virtual contest\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div>\r\n</div>\r\n <script>\r\n $(function () {\r\n $(\".ContestVirtualFrame .sidebar-caption-icon\").click(function() {\r\n $(this).toggleClass(\"la-angle-down la-angle-right\");\r\n const $target = $(this).parent().next();\r\n $target.toggle();\r\n const dataPageUrl = $target.attr(\"data-page-url\");\r\n const collapsed = $(this).hasClass(\"la-angle-right\");\r\n const params = {\r\n action: \"setCollapsed\",\r\n sidebarFrameSimpleClassName: \"ContestVirtualFrame\",\r\n collapsed\r\n };\r\n $.each($target[0].attributes, function(i, a) {\r\n const name = a.name;\r\n if (name.startsWith(\"data-extra-key-\")) {\r\n const key = a.value;\r\n const keyIndex = parseInt(name.substring(\"data-extra-key-\".length));\r\n const value = $target.attr(\"data-extra-value-\" + keyIndex);\r\n params[key] = value;\r\n }\r\n });\r\n $.post(dataPageUrl, params, function (result) {\r\n if (result[\"success\"] !== \"true\") {\r\n Codeforces.showMessage(\"Failed to save collapsed state.\");\r\n }\r\n }, \"json\");\r\n return false;\r\n });\r\n })\r\n </script>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Problem tags\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Implementation problems, programming technics, simulation\">\r\n implementation\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Difficulty\">\r\n *800\r\n</span>\r\n </div>\n <div style=\"clear:both;text-align:right;font-size:1.1rem;\">\r\n <span title=\"Please login into the Codeforces\" class=\"notice\">No tag edit access</span>\r\n </div>\r\n</div>\r\n </div>\n\r\n<form id=\"addTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='e142b1496b4919b3b6a82917f5b7e4d4'/>\r\n <input name=\"action\" type=\"hidden\" value=\"addTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"5686\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<form id=\"removeTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='e142b1496b4919b3b6a82917f5b7e4d4'/>\r\n <input name=\"action\" type=\"hidden\" value=\"removeTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"5686\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<script type=\"text/javascript\">\r\n $(\".tag-box img\").click(function () {\r\n var tagName = $(this).attr(\"value\");\r\n Codeforces.confirm(\"Are you sure you want to remove this tag?\", function () {\r\n $(\"#removeTagForm input[name=tagName]\").val(tagName);\r\n $(\"#removeTagForm\").submit();\r\n }, function () {\r\n }, \"Yes\", \"No\");\r\n });\r\n\r\n $(\"#addTagLink\").click(function () {\r\n $(this).hide();\r\n $(\"#addTagLabel\").show();\r\n return false;\r\n });\r\n\r\n $(\"#addTagSelect\").change(function () {\r\n var tagName = $(this).val();\r\n if (tagName === \"\") {\r\n $(\"#addTagLabel\").hide();\r\n $(\"#addTagLink\").show();\r\n } else {\r\n $(\"#addTagForm input[name=tagName]\").val(tagName);\r\n $(\"#addTagForm\").submit();\r\n }\r\n });\r\n</script>\r\n\r\n<style type=\"text/css\">\r\n#new-resource-form tr td {\r\npadding-top: 0.5em;\r\n}\r\n#new-resource-form input:not([type=\"submit\"]) {\r\nfont-size: 0.8em;\r\n}\r\n#new-resource-form select {\r\nfont-size: 0.8em;\r\n}\r\n.new-resource-error {\r\nfont-size: 0.8em;\r\n}\r\n.resource-locale {\r\ncolor: #666;\r\nfont-family: Consolas, \"Andale Mono WT\", \"Andale Mono\", \"Lucida Console\", \"Lucida Sans Typewriter\", \"DejaVu Sans Mono\", \"Bitstream Vera Sans Mono\", \"Liberation Mono\", \"Nimbus Mono L\", Monaco, \"Courier New\", Courier, monospace;\r\n}\r\n</style>\r\n<div class=\"roundbox sidebox sidebar-menu borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Contest materials\n<div class=\"top-links\">\n</div>\n</div>\n<ul>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/10422\" title=\"Testing Round #9\" target=\"_blank\">Testing Round #9</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"2159:2160\" resourceName=\"Announcement\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n</ul>\r\n</div></div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li class=\"current selectedLava\"><a\r\n href=\"/contest/386\">Problems</a></li>\r\n <li><a\r\n href=\"/contest/386/submit\">Submit Code</a></li>\r\n <li><a\r\n href=\"/contest/386/my\">My Submissions</a></li>\r\n <li><a\r\n href=\"/contest/386/status\">Status</a></li>\r\n <li><a\r\n href=\"/contest/386/hacks\">Hacks</a></li>\r\n <li><a\r\n href=\"/contest/386/room/1\">Room</a></li>\r\n <li><a\r\n href=\"/contest/386/standings\">Standings</a></li>\r\n <li><a\r\n href=\"/contest/386/customtest\">Custom Invocation</a></li>\r\n</ul>\r\n</div>\n\r\n <style>\r\n #facebox .content:has(.diff-popup) {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n }\r\n\r\n .testCaseMarker {\r\n position: absolute;\r\n font-weight: bold;\r\n font-size: 1rem;\r\n }\r\n\r\n .diff-popup {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n display: none;\r\n overflow: auto;\r\n }\r\n\r\n .input-output-copier {\r\n font-size: 1.2rem;\r\n float: right;\r\n color: #888 !important;\r\n cursor: pointer;\r\n border: 1px solid rgb(185, 185, 185);\r\n padding: 3px;\r\n margin: 1px;\r\n line-height: 1.1rem;\r\n text-transform: none;\r\n }\r\n\r\n .input-output-copier:hover {\r\n background-color: #def;\r\n }\r\n\r\n .test-explanation textarea {\r\n width: 100%;\r\n height: 1.5em;\r\n }\r\n\r\n .pending-submission-message {\r\n color: darkorange !important;\r\n }\r\n </style>\r\n <script>\r\n const OPENING_SPACE = String.fromCharCode(1001);\r\n const CLOSING_SPACE = String.fromCharCode(1002);\r\n\r\n const nodeToText = function (node, pre) {\r\n let result = [];\r\n\r\n if (node.tagName === \"SCRIPT\" || node.tagName === \"math\"\r\n || (node.classList && node.classList.contains(\"input-output-copier\")))\r\n return [];\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(OPENING_SPACE);\r\n }\r\n\r\n if (node.nodeType === Node.TEXT_NODE) {\r\n let s = node.textContent;\r\n if (!pre) {\r\n s = s.replace(/\\s+/g, \" \");\r\n }\r\n if (s.length > 0) {\r\n result.push(s);\r\n }\r\n }\r\n\r\n if (pre && node.tagName === \"BR\") {\r\n result.push(\"\\n\");\r\n }\r\n\r\n node.childNodes.forEach(function (child) {\r\n result.push(nodeToText(child, node.tagName === \"PRE\").join(\"\"));\r\n });\r\n\r\n if (node.tagName === \"DIV\"\r\n || node.tagName === \"P\"\r\n || node.tagName === \"PRE\"\r\n || node.tagName === \"UL\"\r\n || node.tagName === \"LI\"\r\n ) {\r\n result.push(\"\\n\");\r\n }\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(CLOSING_SPACE);\r\n }\r\n\r\n return result;\r\n }\r\n\r\n const isSpecial = function (c) {\r\n return c === ',' || c === '.' || c === ';' || c === ')' || c === ' ';\r\n }\r\n\r\n const convertStatementToText = function(statmentNode) {\r\n const text = nodeToText(statmentNode, false).join(\"\").replace(/ +/g, \" \").replace(/\\n\\n+/g, \"\\n\\n\");\r\n let result = [];\r\n for (let i = 0; i < text.length; i++) {\r\n const c = text.charAt(i);\r\n if (c === OPENING_SPACE) {\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"A\" data-uuid=\"ps_8948bd60968257f53ba2e2dbf29103b675479e18\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">A. Second-Price Auction</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>In this problem we consider a special type of an auction, which is called the second-price auction. As in regular auction <span class=\"tex-span\"><i>n</i></span> bidders place a bid which is price a bidder ready to pay. The auction is closed, that is, each bidder secretly informs the organizer of the auction price he is willing to pay. After that, the auction winner is the participant who offered the highest price. However, he pay not the price he offers, but the highest price among the offers of other participants (hence the name: the second-price auction).</p><p>Write a program that reads prices offered by bidders and finds the winner and the price he will pay. Consider that all of the offered prices are different.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line of the input contains <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">2 ≤ <i>n</i> ≤ 1000</span>) — number of bidders. The second line contains <span class=\"tex-span\"><i>n</i></span> distinct integer numbers <span class=\"tex-span\"><i>p</i><sub class=\"lower-index\">1</sub>, <i>p</i><sub class=\"lower-index\">2</sub>, ... <i>p</i><sub class=\"lower-index\"><i>n</i></sub></span>, separated by single spaces (<span class=\"tex-span\">1 ≤ <i>p</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 10000</span>), where <span class=\"tex-span\"><i>p</i><sub class=\"lower-index\"><i>i</i></sub></span> stands for the price offered by the <span class=\"tex-span\"><i>i</i></span>-th bidder.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>The single output line should contain two integers: index of the winner and the price he will pay. Indices are 1-based.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>2<br />5 7<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>2 5<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3<br />10 2 8<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1 8<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>6<br />3 8 2 9 4 14<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>6 9<br /></pre></div></div></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=A]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== statementText) {\r\n $problem.find(\".diff-notifier\").show();\r\n\r\n $problem.find(\".diff-notifier-close\").click(function() {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n $problem.find(\".diff-notifier\").hide();\r\n });\r\n\r\n $problem.find(\"a.view-changes\").click(function() {\r\n $.post(\"/data/diff\", {action: \"getDiff\", a: previousStatementText, b: statementText}, function (result) {\r\n if (result[\"success\"] === \"true\") {\r\n Codeforces.facebox(\".diff-popup\", \"//codeforces.org/s/73366\");\r\n $(\"#facebox .diff-popup\").html(result[\"diff\"]);\r\n }\r\n }, \"json\");\r\n });\r\n }\r\n } else {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n }\r\n });\r\n });\r\n </script>\r\n\r\n\r\n<script type=\"text/javascript\">\r\n $(document).ready(function () {\r\n window.changedTests = new Set();\r\n\r\n function endsWith(string, suffix) {\r\n return string.indexOf(suffix, string.length - suffix.length) !== -1;\r\n }\r\n\r\n const inputFileDiv = $(\"div.input-file\");\r\n const inputFile = inputFileDiv.text();\r\n const outputFileDiv = $(\"div.output-file\");\r\n const outputFile = outputFileDiv.text();\r\n\r\n\r\n if (!endsWith(inputFile, \"standard input\")\r\n && !endsWith(inputFile, \"standard input\")) {\r\n inputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n if (!endsWith(outputFile, \"standard output\")\r\n && !endsWith(outputFile, \"standard output\")) {\r\n outputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n const titleDiv = $(\"div.header div.title\");\r\n\r\n\r\n\r\n String.prototype.replaceAll = function (search, replace) {\r\n return this.split(search).join(replace);\r\n };\r\n\r\n $(\".sample-test .title\").each(function () {\r\n const preId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n const cpyId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n\r\n $(this).parent().find(\"pre\").attr(\"id\", preId);\r\n const $copy = $(\"<div title='Copy' data-clipboard-target='#\" + preId + \"' id='\" + cpyId + \"' class='input-output-copier'>Copy</div>\");\r\n $(this).append($copy);\r\n\r\n const clipboard = new Clipboard('#' + cpyId, {\r\n text: function (trigger) {\r\n const pre = document.querySelector('#' + preId);\r\n const lines = pre.querySelectorAll(\".test-example-line\");\r\n return Codeforces.filterClipboardText(pre.innerText, lines.length);\r\n }\r\n });\r\n\r\n const isInput = $(this).parent().hasClass(\"input\");\r\n\r\n clipboard.on('success', function (e) {\r\n if (isInput) {\r\n Codeforces.showMessage(\"The example input has been copied into the clipboard\");\r\n } else {\r\n Codeforces.showMessage(\"The example output has been copied into the clipboard\");\r\n }\r\n e.clearSelection();\r\n });\r\n });\r\n\r\n $(\".test-form-item input\").change(function () {\r\n addPendingSubmissionMessage($($(this).closest(\"form\")), \"You changed the answer, do not forget to submit it if you want to save the changes\");\r\n const index = $(this).closest(\".problemindexholder\").attr(\"problemindex\");\r\n let test = \"\";\r\n $(this).closest(\"form input\").each(function () {\r\n const test_ = $(this).attr(\"name\");\r\n if (test_ && test_.substring(0, 4) === \"test\") {\r\n test = test_;\r\n }\r\n });\r\n if (index.length > 0 && test.length > 0) {\r\n const indexTest = index + \"::\" + test;\r\n window.changedTests.add(indexTest);\r\n }\r\n });\r\n\r\n $(window).on('beforeunload', function () {\r\n if (window.changedTests.size > 0) {\r\n return 'Dialog text here';\r\n }\r\n });\r\n\r\n autosize($('.test-explanation textarea'));\r\n\r\n $(\".test-example-line\").hover(function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n let top = 1E20;\r\n let left = 1E20;\r\n let problem = $(this).closest(\".problemindexholder\");\r\n $(this).closest(\".input\").find(\".\" + clazz).css(\"background-color\", \"#FFFDE7\").each(function() {\r\n top = Math.min(top, $(this).offset().top);\r\n left = Math.min(left, $(this).offset().left);\r\n });\r\n let testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n if (testCaseMarker.length === 0) {\r\n const html = \"<div class=\\\"testCaseMarker testCaseMarker_\" + end + \" notice\\\"></div>\";\r\n problem.append($(html));\r\n testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n }\r\n if (testCaseMarker) {\r\n testCaseMarker.show()\r\n .offset({top, left: left - 20})\r\n .text(end);\r\n }\r\n }\r\n }\r\n });\r\n }, function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n $(\".\" + clazz).css(\"background-color\", \"\");\r\n $(this).closest(\".problemindexholder\").find(\".testCaseMarker_\" + end).hide();\r\n }\r\n }\r\n });\r\n });\r\n\r\n });\r\n</script>\r\n\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 05:38:17</span> (j3).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/73366/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/73366/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/73366/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/73366/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-73366.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'8122c45dfae77b4f',t:'MTY5NjY0NjI5Ny40ODEwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"},"long_tags":{"kind":"string","value":"[\"Implementation problems, programming technics, simulation\"]"},"short_tags":{"kind":"string","value":"[\"implementation\", \"*800\"]"},"tutorial_link":{"kind":"string","value":""},"tutorial_page":{"kind":"string","value":""}}},{"rowIdx":1950,"cells":{"problem_id":{"kind":"string","value":"386B"},"contest":{"kind":"string","value":"386"},"problem":{"kind":"string","value":"B"},"lang":{"kind":"string","value":"en"},"problem_title":{"kind":"string","value":"B. Fly, freebies, fly!"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">B. Fly, freebies, fly!</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Everyone loves a freebie. Especially students.</p><p>It is well-known that if in the night before exam a student opens window, opens the student's record-book and shouts loudly three times \"Fly, freebie, fly!\" — then flown freebie helps him to pass the upcoming exam.</p><p>In the night before the exam on mathematical analysis <span class=\"tex-span\"><i>n</i></span> students living in dormitory shouted treasured words. The <span class=\"tex-span\"><i>i</i></span>-th student made a sacrament at the time <span class=\"tex-span\"><i>t</i><sub class=\"lower-index\"><i>i</i></sub></span>, where <span class=\"tex-span\"><i>t</i><sub class=\"lower-index\"><i>i</i></sub></span> is the number of seconds elapsed since the beginning of the night.</p><p>It is known that the freebie is a capricious and willful lady. That night the freebie was near dormitory only for <span class=\"tex-span\"><i>T</i></span> seconds. Therefore, if for two students their sacrament times differ for more than <span class=\"tex-span\"><i>T</i></span>, then the freebie didn't visit at least one of them.</p><p>Since all students are optimists, they really want to know what is the maximal number of students visited by the freebie can be.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line of the input contains integer <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">1 ≤ <i>n</i> ≤ 100</span>), where <span class=\"tex-span\"><i>n</i></span> — the number of students shouted \"Fly, freebie, fly!\" The second line contains <span class=\"tex-span\"><i>n</i></span> positive integers <span class=\"tex-span\"><i>t</i><sub class=\"lower-index\"><i>i</i></sub></span> (<span class=\"tex-span\">1 ≤ <i>t</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 1000</span>).</p><p>The last line contains integer <span class=\"tex-span\"><i>T</i></span> (<span class=\"tex-span\">1 ≤ <i>T</i> ≤ 1000</span>) — the time interval during which the freebie was near the dormitory.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print a single integer — the largest number of people who will pass exam tomorrow because of the freebie visit.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>6<br/>4 1 7 8 3 8<br/>1<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>3<br/></pre></div></div></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"f63f33ae6be388a7b5a0aeec13f1a1f8\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - B - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"44c637d2380d90080d2a194660db8ac80257ad59\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - B - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/73366/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/73366/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/73366/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/73366/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/73366/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/73366/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/73366/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/73366/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/73366/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/73366/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/73366/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/73366/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/73366/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/73366/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/sidebar-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/a037fe51637846d9c7c725713cd840ea/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='f63f33ae6be388a7b5a0aeec13f1a1f8'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/73366/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/73366/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fcontest%2F386%2Fproblem%2FB%3Flocale%3Den\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"current\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='f63f33ae6be388a7b5a0aeec13f1a1f8'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:100%;\"><a style=\"color: black\" href=\"/contest/386\">Testing Round 9</a></th>\n </tr>\n <tr>\n <td class=\"left bottom\" colspan=\"1\"><span class=\"contest-state-phase\">Finished</span></td>\n </tr>\n </tbody>\n </table>\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Practice?\n <div class=\"top-links\">\n </div>\n </div>\n<div>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Want to solve the contest problems after the official contest ends? Just register for practice and you will be able to submit solutions.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"\" method=\"post\"><input type='hidden' name='csrf_token' value='f63f33ae6be388a7b5a0aeec13f1a1f8'/>\r\n <input type=\"hidden\" name=\"action\" value=\"registerForPractice\"/>\r\n <input type=\"submit\" name=\"submit\" value=\"Register for practice\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div> \r\n</div>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox ContestVirtualFrame borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Virtual participation <i class=\"sidebar-caption-icon las la-angle-down\"></i>\r\n\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\" \"\r\n\r\n data-page-url=\"/data/sidebarFrames\"\r\n\r\n>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests.\n\nIf you've seen these problems, a virtual contest is not for you - solve these problems in the archive.\n\nIf you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.\n\nNever use someone else's code, read the tutorials or communicate with other person during a virtual contest.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"/contest/386/virtual\" method=\"get\">\r\n <input type=\"submit\" name=\"submit\" value=\"Start virtual contest\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div>\r\n</div>\r\n <script>\r\n $(function () {\r\n $(\".ContestVirtualFrame .sidebar-caption-icon\").click(function() {\r\n $(this).toggleClass(\"la-angle-down la-angle-right\");\r\n const $target = $(this).parent().next();\r\n $target.toggle();\r\n const dataPageUrl = $target.attr(\"data-page-url\");\r\n const collapsed = $(this).hasClass(\"la-angle-right\");\r\n const params = {\r\n action: \"setCollapsed\",\r\n sidebarFrameSimpleClassName: \"ContestVirtualFrame\",\r\n collapsed\r\n };\r\n $.each($target[0].attributes, function(i, a) {\r\n const name = a.name;\r\n if (name.startsWith(\"data-extra-key-\")) {\r\n const key = a.value;\r\n const keyIndex = parseInt(name.substring(\"data-extra-key-\".length));\r\n const value = $target.attr(\"data-extra-value-\" + keyIndex);\r\n params[key] = value;\r\n }\r\n });\r\n $.post(dataPageUrl, params, function (result) {\r\n if (result[\"success\"] !== \"true\") {\r\n Codeforces.showMessage(\"Failed to save collapsed state.\");\r\n }\r\n }, \"json\");\r\n return false;\r\n });\r\n })\r\n </script>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Problem tags\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Binary search\">\r\n binary search\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Brute force\">\r\n brute force\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Implementation problems, programming technics, simulation\">\r\n implementation\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Difficulty\">\r\n *1400\r\n</span>\r\n </div>\n <div style=\"clear:both;text-align:right;font-size:1.1rem;\">\r\n <span title=\"Please login into the Codeforces\" class=\"notice\">No tag edit access</span>\r\n </div>\r\n</div>\r\n </div>\n\r\n<form id=\"addTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='f63f33ae6be388a7b5a0aeec13f1a1f8'/>\r\n <input name=\"action\" type=\"hidden\" value=\"addTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"5687\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<form id=\"removeTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='f63f33ae6be388a7b5a0aeec13f1a1f8'/>\r\n <input name=\"action\" type=\"hidden\" value=\"removeTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"5687\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<script type=\"text/javascript\">\r\n $(\".tag-box img\").click(function () {\r\n var tagName = $(this).attr(\"value\");\r\n Codeforces.confirm(\"Are you sure you want to remove this tag?\", function () {\r\n $(\"#removeTagForm input[name=tagName]\").val(tagName);\r\n $(\"#removeTagForm\").submit();\r\n }, function () {\r\n }, \"Yes\", \"No\");\r\n });\r\n\r\n $(\"#addTagLink\").click(function () {\r\n $(this).hide();\r\n $(\"#addTagLabel\").show();\r\n return false;\r\n });\r\n\r\n $(\"#addTagSelect\").change(function () {\r\n var tagName = $(this).val();\r\n if (tagName === \"\") {\r\n $(\"#addTagLabel\").hide();\r\n $(\"#addTagLink\").show();\r\n } else {\r\n $(\"#addTagForm input[name=tagName]\").val(tagName);\r\n $(\"#addTagForm\").submit();\r\n }\r\n });\r\n</script>\r\n\r\n<style type=\"text/css\">\r\n#new-resource-form tr td {\r\npadding-top: 0.5em;\r\n}\r\n#new-resource-form input:not([type=\"submit\"]) {\r\nfont-size: 0.8em;\r\n}\r\n#new-resource-form select {\r\nfont-size: 0.8em;\r\n}\r\n.new-resource-error {\r\nfont-size: 0.8em;\r\n}\r\n.resource-locale {\r\ncolor: #666;\r\nfont-family: Consolas, \"Andale Mono WT\", \"Andale Mono\", \"Lucida Console\", \"Lucida Sans Typewriter\", \"DejaVu Sans Mono\", \"Bitstream Vera Sans Mono\", \"Liberation Mono\", \"Nimbus Mono L\", Monaco, \"Courier New\", Courier, monospace;\r\n}\r\n</style>\r\n<div class=\"roundbox sidebox sidebar-menu borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Contest materials\n<div class=\"top-links\">\n</div>\n</div>\n<ul>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/10422\" title=\"Testing Round #9\" target=\"_blank\">Testing Round #9</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"2159:2160\" resourceName=\"Announcement\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n</ul>\r\n</div></div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li class=\"current selectedLava\"><a\r\n href=\"/contest/386\">Problems</a></li>\r\n <li><a\r\n href=\"/contest/386/submit\">Submit Code</a></li>\r\n <li><a\r\n href=\"/contest/386/my\">My Submissions</a></li>\r\n <li><a\r\n href=\"/contest/386/status\">Status</a></li>\r\n <li><a\r\n href=\"/contest/386/hacks\">Hacks</a></li>\r\n <li><a\r\n href=\"/contest/386/room/1\">Room</a></li>\r\n <li><a\r\n href=\"/contest/386/standings\">Standings</a></li>\r\n <li><a\r\n href=\"/contest/386/customtest\">Custom Invocation</a></li>\r\n</ul>\r\n</div>\n\r\n <style>\r\n #facebox .content:has(.diff-popup) {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n }\r\n\r\n .testCaseMarker {\r\n position: absolute;\r\n font-weight: bold;\r\n font-size: 1rem;\r\n }\r\n\r\n .diff-popup {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n display: none;\r\n overflow: auto;\r\n }\r\n\r\n .input-output-copier {\r\n font-size: 1.2rem;\r\n float: right;\r\n color: #888 !important;\r\n cursor: pointer;\r\n border: 1px solid rgb(185, 185, 185);\r\n padding: 3px;\r\n margin: 1px;\r\n line-height: 1.1rem;\r\n text-transform: none;\r\n }\r\n\r\n .input-output-copier:hover {\r\n background-color: #def;\r\n }\r\n\r\n .test-explanation textarea {\r\n width: 100%;\r\n height: 1.5em;\r\n }\r\n\r\n .pending-submission-message {\r\n color: darkorange !important;\r\n }\r\n </style>\r\n <script>\r\n const OPENING_SPACE = String.fromCharCode(1001);\r\n const CLOSING_SPACE = String.fromCharCode(1002);\r\n\r\n const nodeToText = function (node, pre) {\r\n let result = [];\r\n\r\n if (node.tagName === \"SCRIPT\" || node.tagName === \"math\"\r\n || (node.classList && node.classList.contains(\"input-output-copier\")))\r\n return [];\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(OPENING_SPACE);\r\n }\r\n\r\n if (node.nodeType === Node.TEXT_NODE) {\r\n let s = node.textContent;\r\n if (!pre) {\r\n s = s.replace(/\\s+/g, \" \");\r\n }\r\n if (s.length > 0) {\r\n result.push(s);\r\n }\r\n }\r\n\r\n if (pre && node.tagName === \"BR\") {\r\n result.push(\"\\n\");\r\n }\r\n\r\n node.childNodes.forEach(function (child) {\r\n result.push(nodeToText(child, node.tagName === \"PRE\").join(\"\"));\r\n });\r\n\r\n if (node.tagName === \"DIV\"\r\n || node.tagName === \"P\"\r\n || node.tagName === \"PRE\"\r\n || node.tagName === \"UL\"\r\n || node.tagName === \"LI\"\r\n ) {\r\n result.push(\"\\n\");\r\n }\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(CLOSING_SPACE);\r\n }\r\n\r\n return result;\r\n }\r\n\r\n const isSpecial = function (c) {\r\n return c === ',' || c === '.' || c === ';' || c === ')' || c === ' ';\r\n }\r\n\r\n const convertStatementToText = function(statmentNode) {\r\n const text = nodeToText(statmentNode, false).join(\"\").replace(/ +/g, \" \").replace(/\\n\\n+/g, \"\\n\\n\");\r\n let result = [];\r\n for (let i = 0; i < text.length; i++) {\r\n const c = text.charAt(i);\r\n if (c === OPENING_SPACE) {\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"B\" data-uuid=\"ps_9414281e6e05736e178f361657c7a4a185506cbb\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">B. Fly, freebies, fly!</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Everyone loves a freebie. Especially students.</p><p>It is well-known that if in the night before exam a student opens window, opens the student's record-book and shouts loudly three times "Fly, freebie, fly!" — then flown freebie helps him to pass the upcoming exam.</p><p>In the night before the exam on mathematical analysis <span class=\"tex-span\"><i>n</i></span> students living in dormitory shouted treasured words. The <span class=\"tex-span\"><i>i</i></span>-th student made a sacrament at the time <span class=\"tex-span\"><i>t</i><sub class=\"lower-index\"><i>i</i></sub></span>, where <span class=\"tex-span\"><i>t</i><sub class=\"lower-index\"><i>i</i></sub></span> is the number of seconds elapsed since the beginning of the night.</p><p>It is known that the freebie is a capricious and willful lady. That night the freebie was near dormitory only for <span class=\"tex-span\"><i>T</i></span> seconds. Therefore, if for two students their sacrament times differ for more than <span class=\"tex-span\"><i>T</i></span>, then the freebie didn't visit at least one of them.</p><p>Since all students are optimists, they really want to know what is the maximal number of students visited by the freebie can be.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line of the input contains integer <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">1 ≤ <i>n</i> ≤ 100</span>), where <span class=\"tex-span\"><i>n</i></span> — the number of students shouted "Fly, freebie, fly!" The second line contains <span class=\"tex-span\"><i>n</i></span> positive integers <span class=\"tex-span\"><i>t</i><sub class=\"lower-index\"><i>i</i></sub></span> (<span class=\"tex-span\">1 ≤ <i>t</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 1000</span>).</p><p>The last line contains integer <span class=\"tex-span\"><i>T</i></span> (<span class=\"tex-span\">1 ≤ <i>T</i> ≤ 1000</span>) — the time interval during which the freebie was near the dormitory.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print a single integer — the largest number of people who will pass exam tomorrow because of the freebie visit.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>6<br />4 1 7 8 3 8<br />1<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>3<br /></pre></div></div></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=B]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== statementText) {\r\n $problem.find(\".diff-notifier\").show();\r\n\r\n $problem.find(\".diff-notifier-close\").click(function() {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n $problem.find(\".diff-notifier\").hide();\r\n });\r\n\r\n $problem.find(\"a.view-changes\").click(function() {\r\n $.post(\"/data/diff\", {action: \"getDiff\", a: previousStatementText, b: statementText}, function (result) {\r\n if (result[\"success\"] === \"true\") {\r\n Codeforces.facebox(\".diff-popup\", \"//codeforces.org/s/73366\");\r\n $(\"#facebox .diff-popup\").html(result[\"diff\"]);\r\n }\r\n }, \"json\");\r\n });\r\n }\r\n } else {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n }\r\n });\r\n });\r\n </script>\r\n\r\n\r\n<script type=\"text/javascript\">\r\n $(document).ready(function () {\r\n window.changedTests = new Set();\r\n\r\n function endsWith(string, suffix) {\r\n return string.indexOf(suffix, string.length - suffix.length) !== -1;\r\n }\r\n\r\n const inputFileDiv = $(\"div.input-file\");\r\n const inputFile = inputFileDiv.text();\r\n const outputFileDiv = $(\"div.output-file\");\r\n const outputFile = outputFileDiv.text();\r\n\r\n\r\n if (!endsWith(inputFile, \"standard input\")\r\n && !endsWith(inputFile, \"standard input\")) {\r\n inputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n if (!endsWith(outputFile, \"standard output\")\r\n && !endsWith(outputFile, \"standard output\")) {\r\n outputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n const titleDiv = $(\"div.header div.title\");\r\n\r\n\r\n\r\n String.prototype.replaceAll = function (search, replace) {\r\n return this.split(search).join(replace);\r\n };\r\n\r\n $(\".sample-test .title\").each(function () {\r\n const preId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n const cpyId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n\r\n $(this).parent().find(\"pre\").attr(\"id\", preId);\r\n const $copy = $(\"<div title='Copy' data-clipboard-target='#\" + preId + \"' id='\" + cpyId + \"' class='input-output-copier'>Copy</div>\");\r\n $(this).append($copy);\r\n\r\n const clipboard = new Clipboard('#' + cpyId, {\r\n text: function (trigger) {\r\n const pre = document.querySelector('#' + preId);\r\n const lines = pre.querySelectorAll(\".test-example-line\");\r\n return Codeforces.filterClipboardText(pre.innerText, lines.length);\r\n }\r\n });\r\n\r\n const isInput = $(this).parent().hasClass(\"input\");\r\n\r\n clipboard.on('success', function (e) {\r\n if (isInput) {\r\n Codeforces.showMessage(\"The example input has been copied into the clipboard\");\r\n } else {\r\n Codeforces.showMessage(\"The example output has been copied into the clipboard\");\r\n }\r\n e.clearSelection();\r\n });\r\n });\r\n\r\n $(\".test-form-item input\").change(function () {\r\n addPendingSubmissionMessage($($(this).closest(\"form\")), \"You changed the answer, do not forget to submit it if you want to save the changes\");\r\n const index = $(this).closest(\".problemindexholder\").attr(\"problemindex\");\r\n let test = \"\";\r\n $(this).closest(\"form input\").each(function () {\r\n const test_ = $(this).attr(\"name\");\r\n if (test_ && test_.substring(0, 4) === \"test\") {\r\n test = test_;\r\n }\r\n });\r\n if (index.length > 0 && test.length > 0) {\r\n const indexTest = index + \"::\" + test;\r\n window.changedTests.add(indexTest);\r\n }\r\n });\r\n\r\n $(window).on('beforeunload', function () {\r\n if (window.changedTests.size > 0) {\r\n return 'Dialog text here';\r\n }\r\n });\r\n\r\n autosize($('.test-explanation textarea'));\r\n\r\n $(\".test-example-line\").hover(function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n let top = 1E20;\r\n let left = 1E20;\r\n let problem = $(this).closest(\".problemindexholder\");\r\n $(this).closest(\".input\").find(\".\" + clazz).css(\"background-color\", \"#FFFDE7\").each(function() {\r\n top = Math.min(top, $(this).offset().top);\r\n left = Math.min(left, $(this).offset().left);\r\n });\r\n let testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n if (testCaseMarker.length === 0) {\r\n const html = \"<div class=\\\"testCaseMarker testCaseMarker_\" + end + \" notice\\\"></div>\";\r\n problem.append($(html));\r\n testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n }\r\n if (testCaseMarker) {\r\n testCaseMarker.show()\r\n .offset({top, left: left - 20})\r\n .text(end);\r\n }\r\n }\r\n }\r\n });\r\n }, function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n $(\".\" + clazz).css(\"background-color\", \"\");\r\n $(this).closest(\".problemindexholder\").find(\".testCaseMarker_\" + end).hide();\r\n }\r\n }\r\n });\r\n });\r\n\r\n });\r\n</script>\r\n\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 05:38:18</span> (j3).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/73366/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/73366/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/73366/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/73366/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-73366.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'8122c466c9059d37',t:'MTY5NjY0NjI5OC43NzgwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"},"long_tags":{"kind":"string","value":"[\"Binary search\", \"Brute force\", \"Implementation problems, programming technics, simulation\"]"},"short_tags":{"kind":"string","value":"[\"binary search\", \"brute force\", \"implementation\", \"*1400\"]"},"tutorial_link":{"kind":"string","value":""},"tutorial_page":{"kind":"string","value":""}}},{"rowIdx":1951,"cells":{"problem_id":{"kind":"string","value":"386C"},"contest":{"kind":"string","value":"386"},"problem":{"kind":"string","value":"C"},"lang":{"kind":"string","value":"en"},"problem_title":{"kind":"string","value":"C. Diverse Substrings"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">C. Diverse Substrings</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p><span class=\"tex-font-style-it\">String diversity</span> is the number of symbols that occur in the string at least once. Diversity of <span class=\"tex-span\"><i>s</i></span> will be denoted by <span class=\"tex-span\"><i>d</i>(<i>s</i>)</span>. For example , <span class=\"tex-span\"><i>d</i></span>(\"<span class=\"tex-font-style-tt\">aaa</span>\")=1, <span class=\"tex-span\"><i>d</i></span>(\"<span class=\"tex-font-style-tt\">abacaba</span>\")=3.</p><p>Given a string <span class=\"tex-span\"><i>s</i></span>, consisting of lowercase Latin letters. Consider all its substrings. Obviously, any substring diversity is a number from 1 to <span class=\"tex-span\"><i>d</i>(<i>s</i>)</span>. Find statistics about substrings diversity: for each <span class=\"tex-span\"><i>k</i></span> from 1 to <span class=\"tex-span\"><i>d</i>(<i>s</i>)</span>, find how many substrings of <span class=\"tex-span\"><i>s</i></span> has a diversity of exactly <span class=\"tex-span\"><i>k</i></span>.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The input consists of a single line containing <span class=\"tex-span\"><i>s</i></span>. It contains only lowercase Latin letters, the length of <span class=\"tex-span\"><i>s</i></span> is from 1 to <span class=\"tex-span\">3·10<sup class=\"upper-index\">5</sup></span>.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print to the first line the value <span class=\"tex-span\"><i>d</i>(<i>s</i>)</span>. Print sequence <span class=\"tex-span\"><i>t</i><sub class=\"lower-index\">1</sub>, <i>t</i><sub class=\"lower-index\">2</sub>, ..., <i>t</i><sub class=\"lower-index\"><i>d</i>(<i>s</i>)</sub></span> to the following lines, where <span class=\"tex-span\"><i>t</i><sub class=\"lower-index\"><i>i</i></sub></span> is the number of substrings of <span class=\"tex-span\"><i>s</i></span> having diversity of exactly <span class=\"tex-span\"><i>i</i></span>.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>abca<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>3<br/>4<br/>3<br/>3<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>aabacaabbad<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>4<br/>14<br/>19<br/>28<br/>5<br/></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>Consider the first example.</p><p>We denote by <span class=\"tex-span\"><i>s</i>(<i>i</i>, <i>j</i>)</span> a substring of \"<span class=\"tex-font-style-tt\">abca</span>\" with the indices in the segment <span class=\"tex-span\">[<i>i</i>, <i>j</i>]</span>.</p><ul> <li> <span class=\"tex-span\"><i>s</i>(1, 1) = </span> \"<span class=\"tex-font-style-tt\">a</span>\", <span class=\"tex-span\"><i>d</i>(</span>\"<span class=\"tex-font-style-tt\">a</span>\"<span class=\"tex-span\">) = 1</span> </li><li> <span class=\"tex-span\"><i>s</i>(2, 2) = </span> \"<span class=\"tex-font-style-tt\">b</span>\", <span class=\"tex-span\"><i>d</i>(</span>\"<span class=\"tex-font-style-tt\">b</span>\"<span class=\"tex-span\">) = 1</span> </li><li> <span class=\"tex-span\"><i>s</i>(3, 3) = </span> \"<span class=\"tex-font-style-tt\">c</span>\", <span class=\"tex-span\"><i>d</i>(</span>\"<span class=\"tex-font-style-tt\">c</span>\"<span class=\"tex-span\">) = 1</span> </li><li> <span class=\"tex-span\"><i>s</i>(4, 4) = </span> \"<span class=\"tex-font-style-tt\">a</span>\", <span class=\"tex-span\"><i>d</i>(</span>\"<span class=\"tex-font-style-tt\">a</span>\"<span class=\"tex-span\">) = 1</span> </li><li> <span class=\"tex-span\"><i>s</i>(1, 2) = </span> \"<span class=\"tex-font-style-tt\">ab</span>\", <span class=\"tex-span\"><i>d</i>(</span>\"<span class=\"tex-font-style-tt\">ab</span>\"<span class=\"tex-span\">) = 2</span> </li><li> <span class=\"tex-span\"><i>s</i>(2, 3) = </span> \"<span class=\"tex-font-style-tt\">bc</span>\", <span class=\"tex-span\"><i>d</i>(</span>\"<span class=\"tex-font-style-tt\">bc</span>\"<span class=\"tex-span\">) = 2</span> </li><li> <span class=\"tex-span\"><i>s</i>(3, 4) = </span> \"<span class=\"tex-font-style-tt\">ca</span>\", <span class=\"tex-span\"><i>d</i>(</span>\"<span class=\"tex-font-style-tt\">ca</span>\"<span class=\"tex-span\">) = 2</span> </li><li> <span class=\"tex-span\"><i>s</i>(1, 3) = </span> \"<span class=\"tex-font-style-tt\">abc</span>\", <span class=\"tex-span\"><i>d</i>(</span>\"<span class=\"tex-font-style-tt\">abc</span>\"<span class=\"tex-span\">) = 3</span> </li><li> <span class=\"tex-span\"><i>s</i>(2, 4) = </span> \"<span class=\"tex-font-style-tt\">bca</span>\", <span class=\"tex-span\"><i>d</i>(</span>\"<span class=\"tex-font-style-tt\">bca</span>\"<span class=\"tex-span\">) = 3</span> </li><li> <span class=\"tex-span\"><i>s</i>(1, 4) = </span> \"<span class=\"tex-font-style-tt\">abca</span>\", <span class=\"tex-span\"><i>d</i>(</span>\"<span class=\"tex-font-style-tt\">abca</span>\"<span class=\"tex-span\">) = 3</span> </li></ul><p>Total number of substring with diversity 1 is 4, with diversity 2 equals 3, 3 diversity is 3.</p></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"549aa50237dde31664f6f54324523d03\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - C - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"44c637d2380d90080d2a194660db8ac80257ad59\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - C - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/73366/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/73366/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/73366/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/73366/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/73366/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/73366/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/73366/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/73366/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/73366/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/73366/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/73366/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/73366/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/73366/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/73366/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/sidebar-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/a037fe51637846d9c7c725713cd840ea/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='549aa50237dde31664f6f54324523d03'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/73366/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/73366/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fcontest%2F386%2Fproblem%2FC%3Flocale%3Den\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"current\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='549aa50237dde31664f6f54324523d03'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:100%;\"><a style=\"color: black\" href=\"/contest/386\">Testing Round 9</a></th>\n </tr>\n <tr>\n <td class=\"left bottom\" colspan=\"1\"><span class=\"contest-state-phase\">Finished</span></td>\n </tr>\n </tbody>\n </table>\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Practice?\n <div class=\"top-links\">\n </div>\n </div>\n<div>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Want to solve the contest problems after the official contest ends? Just register for practice and you will be able to submit solutions.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"\" method=\"post\"><input type='hidden' name='csrf_token' value='549aa50237dde31664f6f54324523d03'/>\r\n <input type=\"hidden\" name=\"action\" value=\"registerForPractice\"/>\r\n <input type=\"submit\" name=\"submit\" value=\"Register for practice\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div> \r\n</div>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox ContestVirtualFrame borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Virtual participation <i class=\"sidebar-caption-icon las la-angle-down\"></i>\r\n\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\" \"\r\n\r\n data-page-url=\"/data/sidebarFrames\"\r\n\r\n>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests.\n\nIf you've seen these problems, a virtual contest is not for you - solve these problems in the archive.\n\nIf you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.\n\nNever use someone else's code, read the tutorials or communicate with other person during a virtual contest.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"/contest/386/virtual\" method=\"get\">\r\n <input type=\"submit\" name=\"submit\" value=\"Start virtual contest\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div>\r\n</div>\r\n <script>\r\n $(function () {\r\n $(\".ContestVirtualFrame .sidebar-caption-icon\").click(function() {\r\n $(this).toggleClass(\"la-angle-down la-angle-right\");\r\n const $target = $(this).parent().next();\r\n $target.toggle();\r\n const dataPageUrl = $target.attr(\"data-page-url\");\r\n const collapsed = $(this).hasClass(\"la-angle-right\");\r\n const params = {\r\n action: \"setCollapsed\",\r\n sidebarFrameSimpleClassName: \"ContestVirtualFrame\",\r\n collapsed\r\n };\r\n $.each($target[0].attributes, function(i, a) {\r\n const name = a.name;\r\n if (name.startsWith(\"data-extra-key-\")) {\r\n const key = a.value;\r\n const keyIndex = parseInt(name.substring(\"data-extra-key-\".length));\r\n const value = $target.attr(\"data-extra-value-\" + keyIndex);\r\n params[key] = value;\r\n }\r\n });\r\n $.post(dataPageUrl, params, function (result) {\r\n if (result[\"success\"] !== \"true\") {\r\n Codeforces.showMessage(\"Failed to save collapsed state.\");\r\n }\r\n }, \"json\");\r\n return false;\r\n });\r\n })\r\n </script>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Problem tags\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Dynamic programming\">\r\n dp\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Prefix- and Z-functions, suffix structures, Knuth–Morris–Pratt algorithm, etc\">\r\n strings\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Two pointers\">\r\n two pointers\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Difficulty\">\r\n *2000\r\n</span>\r\n </div>\n <div style=\"clear:both;text-align:right;font-size:1.1rem;\">\r\n <span title=\"Please login into the Codeforces\" class=\"notice\">No tag edit access</span>\r\n </div>\r\n</div>\r\n </div>\n\r\n<form id=\"addTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='549aa50237dde31664f6f54324523d03'/>\r\n <input name=\"action\" type=\"hidden\" value=\"addTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"5688\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<form id=\"removeTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='549aa50237dde31664f6f54324523d03'/>\r\n <input name=\"action\" type=\"hidden\" value=\"removeTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"5688\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<script type=\"text/javascript\">\r\n $(\".tag-box img\").click(function () {\r\n var tagName = $(this).attr(\"value\");\r\n Codeforces.confirm(\"Are you sure you want to remove this tag?\", function () {\r\n $(\"#removeTagForm input[name=tagName]\").val(tagName);\r\n $(\"#removeTagForm\").submit();\r\n }, function () {\r\n }, \"Yes\", \"No\");\r\n });\r\n\r\n $(\"#addTagLink\").click(function () {\r\n $(this).hide();\r\n $(\"#addTagLabel\").show();\r\n return false;\r\n });\r\n\r\n $(\"#addTagSelect\").change(function () {\r\n var tagName = $(this).val();\r\n if (tagName === \"\") {\r\n $(\"#addTagLabel\").hide();\r\n $(\"#addTagLink\").show();\r\n } else {\r\n $(\"#addTagForm input[name=tagName]\").val(tagName);\r\n $(\"#addTagForm\").submit();\r\n }\r\n });\r\n</script>\r\n\r\n<style type=\"text/css\">\r\n#new-resource-form tr td {\r\npadding-top: 0.5em;\r\n}\r\n#new-resource-form input:not([type=\"submit\"]) {\r\nfont-size: 0.8em;\r\n}\r\n#new-resource-form select {\r\nfont-size: 0.8em;\r\n}\r\n.new-resource-error {\r\nfont-size: 0.8em;\r\n}\r\n.resource-locale {\r\ncolor: #666;\r\nfont-family: Consolas, \"Andale Mono WT\", \"Andale Mono\", \"Lucida Console\", \"Lucida Sans Typewriter\", \"DejaVu Sans Mono\", \"Bitstream Vera Sans Mono\", \"Liberation Mono\", \"Nimbus Mono L\", Monaco, \"Courier New\", Courier, monospace;\r\n}\r\n</style>\r\n<div class=\"roundbox sidebox sidebar-menu borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Contest materials\n<div class=\"top-links\">\n</div>\n</div>\n<ul>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/10422\" title=\"Testing Round #9\" target=\"_blank\">Testing Round #9</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"2159:2160\" resourceName=\"Announcement\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n</ul>\r\n</div></div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li class=\"current selectedLava\"><a\r\n href=\"/contest/386\">Problems</a></li>\r\n <li><a\r\n href=\"/contest/386/submit\">Submit Code</a></li>\r\n <li><a\r\n href=\"/contest/386/my\">My Submissions</a></li>\r\n <li><a\r\n href=\"/contest/386/status\">Status</a></li>\r\n <li><a\r\n href=\"/contest/386/hacks\">Hacks</a></li>\r\n <li><a\r\n href=\"/contest/386/room/1\">Room</a></li>\r\n <li><a\r\n href=\"/contest/386/standings\">Standings</a></li>\r\n <li><a\r\n href=\"/contest/386/customtest\">Custom Invocation</a></li>\r\n</ul>\r\n</div>\n\r\n <style>\r\n #facebox .content:has(.diff-popup) {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n }\r\n\r\n .testCaseMarker {\r\n position: absolute;\r\n font-weight: bold;\r\n font-size: 1rem;\r\n }\r\n\r\n .diff-popup {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n display: none;\r\n overflow: auto;\r\n }\r\n\r\n .input-output-copier {\r\n font-size: 1.2rem;\r\n float: right;\r\n color: #888 !important;\r\n cursor: pointer;\r\n border: 1px solid rgb(185, 185, 185);\r\n padding: 3px;\r\n margin: 1px;\r\n line-height: 1.1rem;\r\n text-transform: none;\r\n }\r\n\r\n .input-output-copier:hover {\r\n background-color: #def;\r\n }\r\n\r\n .test-explanation textarea {\r\n width: 100%;\r\n height: 1.5em;\r\n }\r\n\r\n .pending-submission-message {\r\n color: darkorange !important;\r\n }\r\n </style>\r\n <script>\r\n const OPENING_SPACE = String.fromCharCode(1001);\r\n const CLOSING_SPACE = String.fromCharCode(1002);\r\n\r\n const nodeToText = function (node, pre) {\r\n let result = [];\r\n\r\n if (node.tagName === \"SCRIPT\" || node.tagName === \"math\"\r\n || (node.classList && node.classList.contains(\"input-output-copier\")))\r\n return [];\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(OPENING_SPACE);\r\n }\r\n\r\n if (node.nodeType === Node.TEXT_NODE) {\r\n let s = node.textContent;\r\n if (!pre) {\r\n s = s.replace(/\\s+/g, \" \");\r\n }\r\n if (s.length > 0) {\r\n result.push(s);\r\n }\r\n }\r\n\r\n if (pre && node.tagName === \"BR\") {\r\n result.push(\"\\n\");\r\n }\r\n\r\n node.childNodes.forEach(function (child) {\r\n result.push(nodeToText(child, node.tagName === \"PRE\").join(\"\"));\r\n });\r\n\r\n if (node.tagName === \"DIV\"\r\n || node.tagName === \"P\"\r\n || node.tagName === \"PRE\"\r\n || node.tagName === \"UL\"\r\n || node.tagName === \"LI\"\r\n ) {\r\n result.push(\"\\n\");\r\n }\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(CLOSING_SPACE);\r\n }\r\n\r\n return result;\r\n }\r\n\r\n const isSpecial = function (c) {\r\n return c === ',' || c === '.' || c === ';' || c === ')' || c === ' ';\r\n }\r\n\r\n const convertStatementToText = function(statmentNode) {\r\n const text = nodeToText(statmentNode, false).join(\"\").replace(/ +/g, \" \").replace(/\\n\\n+/g, \"\\n\\n\");\r\n let result = [];\r\n for (let i = 0; i < text.length; i++) {\r\n const c = text.charAt(i);\r\n if (c === OPENING_SPACE) {\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"C\" data-uuid=\"ps_d56cdd0b02338c15239e037054c5e209a453dbcd\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">C. Diverse Substrings</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p><span class=\"tex-font-style-it\">String diversity</span> is the number of symbols that occur in the string at least once. Diversity of <span class=\"tex-span\"><i>s</i></span> will be denoted by <span class=\"tex-span\"><i>d</i>(<i>s</i>)</span>. For example , <span class=\"tex-span\"><i>d</i></span>("<span class=\"tex-font-style-tt\">aaa</span>")=1, <span class=\"tex-span\"><i>d</i></span>("<span class=\"tex-font-style-tt\">abacaba</span>")=3.</p><p>Given a string <span class=\"tex-span\"><i>s</i></span>, consisting of lowercase Latin letters. Consider all its substrings. Obviously, any substring diversity is a number from 1 to <span class=\"tex-span\"><i>d</i>(<i>s</i>)</span>. Find statistics about substrings diversity: for each <span class=\"tex-span\"><i>k</i></span> from 1 to <span class=\"tex-span\"><i>d</i>(<i>s</i>)</span>, find how many substrings of <span class=\"tex-span\"><i>s</i></span> has a diversity of exactly <span class=\"tex-span\"><i>k</i></span>.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The input consists of a single line containing <span class=\"tex-span\"><i>s</i></span>. It contains only lowercase Latin letters, the length of <span class=\"tex-span\"><i>s</i></span> is from 1 to <span class=\"tex-span\">3·10<sup class=\"upper-index\">5</sup></span>.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print to the first line the value <span class=\"tex-span\"><i>d</i>(<i>s</i>)</span>. Print sequence <span class=\"tex-span\"><i>t</i><sub class=\"lower-index\">1</sub>, <i>t</i><sub class=\"lower-index\">2</sub>, ..., <i>t</i><sub class=\"lower-index\"><i>d</i>(<i>s</i>)</sub></span> to the following lines, where <span class=\"tex-span\"><i>t</i><sub class=\"lower-index\"><i>i</i></sub></span> is the number of substrings of <span class=\"tex-span\"><i>s</i></span> having diversity of exactly <span class=\"tex-span\"><i>i</i></span>.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>abca<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>3<br />4<br />3<br />3<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>aabacaabbad<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>4<br />14<br />19<br />28<br />5<br /></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>Consider the first example.</p><p>We denote by <span class=\"tex-span\"><i>s</i>(<i>i</i>, <i>j</i>)</span> a substring of "<span class=\"tex-font-style-tt\">abca</span>" with the indices in the segment <span class=\"tex-span\">[<i>i</i>, <i>j</i>]</span>.</p><ul> <li> <span class=\"tex-span\"><i>s</i>(1, 1) = </span> "<span class=\"tex-font-style-tt\">a</span>", <span class=\"tex-span\"><i>d</i>(</span>"<span class=\"tex-font-style-tt\">a</span>"<span class=\"tex-span\">) = 1</span> </li><li> <span class=\"tex-span\"><i>s</i>(2, 2) = </span> "<span class=\"tex-font-style-tt\">b</span>", <span class=\"tex-span\"><i>d</i>(</span>"<span class=\"tex-font-style-tt\">b</span>"<span class=\"tex-span\">) = 1</span> </li><li> <span class=\"tex-span\"><i>s</i>(3, 3) = </span> "<span class=\"tex-font-style-tt\">c</span>", <span class=\"tex-span\"><i>d</i>(</span>"<span class=\"tex-font-style-tt\">c</span>"<span class=\"tex-span\">) = 1</span> </li><li> <span class=\"tex-span\"><i>s</i>(4, 4) = </span> "<span class=\"tex-font-style-tt\">a</span>", <span class=\"tex-span\"><i>d</i>(</span>"<span class=\"tex-font-style-tt\">a</span>"<span class=\"tex-span\">) = 1</span> </li><li> <span class=\"tex-span\"><i>s</i>(1, 2) = </span> "<span class=\"tex-font-style-tt\">ab</span>", <span class=\"tex-span\"><i>d</i>(</span>"<span class=\"tex-font-style-tt\">ab</span>"<span class=\"tex-span\">) = 2</span> </li><li> <span class=\"tex-span\"><i>s</i>(2, 3) = </span> "<span class=\"tex-font-style-tt\">bc</span>", <span class=\"tex-span\"><i>d</i>(</span>"<span class=\"tex-font-style-tt\">bc</span>"<span class=\"tex-span\">) = 2</span> </li><li> <span class=\"tex-span\"><i>s</i>(3, 4) = </span> "<span class=\"tex-font-style-tt\">ca</span>", <span class=\"tex-span\"><i>d</i>(</span>"<span class=\"tex-font-style-tt\">ca</span>"<span class=\"tex-span\">) = 2</span> </li><li> <span class=\"tex-span\"><i>s</i>(1, 3) = </span> "<span class=\"tex-font-style-tt\">abc</span>", <span class=\"tex-span\"><i>d</i>(</span>"<span class=\"tex-font-style-tt\">abc</span>"<span class=\"tex-span\">) = 3</span> </li><li> <span class=\"tex-span\"><i>s</i>(2, 4) = </span> "<span class=\"tex-font-style-tt\">bca</span>", <span class=\"tex-span\"><i>d</i>(</span>"<span class=\"tex-font-style-tt\">bca</span>"<span class=\"tex-span\">) = 3</span> </li><li> <span class=\"tex-span\"><i>s</i>(1, 4) = </span> "<span class=\"tex-font-style-tt\">abca</span>", <span class=\"tex-span\"><i>d</i>(</span>"<span class=\"tex-font-style-tt\">abca</span>"<span class=\"tex-span\">) = 3</span> </li></ul><p>Total number of substring with diversity 1 is 4, with diversity 2 equals 3, 3 diversity is 3.</p></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=C]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== statementText) {\r\n $problem.find(\".diff-notifier\").show();\r\n\r\n $problem.find(\".diff-notifier-close\").click(function() {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n $problem.find(\".diff-notifier\").hide();\r\n });\r\n\r\n $problem.find(\"a.view-changes\").click(function() {\r\n $.post(\"/data/diff\", {action: \"getDiff\", a: previousStatementText, b: statementText}, function (result) {\r\n if (result[\"success\"] === \"true\") {\r\n Codeforces.facebox(\".diff-popup\", \"//codeforces.org/s/73366\");\r\n $(\"#facebox .diff-popup\").html(result[\"diff\"]);\r\n }\r\n }, \"json\");\r\n });\r\n }\r\n } else {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n }\r\n });\r\n });\r\n </script>\r\n\r\n\r\n<script type=\"text/javascript\">\r\n $(document).ready(function () {\r\n window.changedTests = new Set();\r\n\r\n function endsWith(string, suffix) {\r\n return string.indexOf(suffix, string.length - suffix.length) !== -1;\r\n }\r\n\r\n const inputFileDiv = $(\"div.input-file\");\r\n const inputFile = inputFileDiv.text();\r\n const outputFileDiv = $(\"div.output-file\");\r\n const outputFile = outputFileDiv.text();\r\n\r\n\r\n if (!endsWith(inputFile, \"standard input\")\r\n && !endsWith(inputFile, \"standard input\")) {\r\n inputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n if (!endsWith(outputFile, \"standard output\")\r\n && !endsWith(outputFile, \"standard output\")) {\r\n outputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n const titleDiv = $(\"div.header div.title\");\r\n\r\n\r\n\r\n String.prototype.replaceAll = function (search, replace) {\r\n return this.split(search).join(replace);\r\n };\r\n\r\n $(\".sample-test .title\").each(function () {\r\n const preId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n const cpyId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n\r\n $(this).parent().find(\"pre\").attr(\"id\", preId);\r\n const $copy = $(\"<div title='Copy' data-clipboard-target='#\" + preId + \"' id='\" + cpyId + \"' class='input-output-copier'>Copy</div>\");\r\n $(this).append($copy);\r\n\r\n const clipboard = new Clipboard('#' + cpyId, {\r\n text: function (trigger) {\r\n const pre = document.querySelector('#' + preId);\r\n const lines = pre.querySelectorAll(\".test-example-line\");\r\n return Codeforces.filterClipboardText(pre.innerText, lines.length);\r\n }\r\n });\r\n\r\n const isInput = $(this).parent().hasClass(\"input\");\r\n\r\n clipboard.on('success', function (e) {\r\n if (isInput) {\r\n Codeforces.showMessage(\"The example input has been copied into the clipboard\");\r\n } else {\r\n Codeforces.showMessage(\"The example output has been copied into the clipboard\");\r\n }\r\n e.clearSelection();\r\n });\r\n });\r\n\r\n $(\".test-form-item input\").change(function () {\r\n addPendingSubmissionMessage($($(this).closest(\"form\")), \"You changed the answer, do not forget to submit it if you want to save the changes\");\r\n const index = $(this).closest(\".problemindexholder\").attr(\"problemindex\");\r\n let test = \"\";\r\n $(this).closest(\"form input\").each(function () {\r\n const test_ = $(this).attr(\"name\");\r\n if (test_ && test_.substring(0, 4) === \"test\") {\r\n test = test_;\r\n }\r\n });\r\n if (index.length > 0 && test.length > 0) {\r\n const indexTest = index + \"::\" + test;\r\n window.changedTests.add(indexTest);\r\n }\r\n });\r\n\r\n $(window).on('beforeunload', function () {\r\n if (window.changedTests.size > 0) {\r\n return 'Dialog text here';\r\n }\r\n });\r\n\r\n autosize($('.test-explanation textarea'));\r\n\r\n $(\".test-example-line\").hover(function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n let top = 1E20;\r\n let left = 1E20;\r\n let problem = $(this).closest(\".problemindexholder\");\r\n $(this).closest(\".input\").find(\".\" + clazz).css(\"background-color\", \"#FFFDE7\").each(function() {\r\n top = Math.min(top, $(this).offset().top);\r\n left = Math.min(left, $(this).offset().left);\r\n });\r\n let testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n if (testCaseMarker.length === 0) {\r\n const html = \"<div class=\\\"testCaseMarker testCaseMarker_\" + end + \" notice\\\"></div>\";\r\n problem.append($(html));\r\n testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n }\r\n if (testCaseMarker) {\r\n testCaseMarker.show()\r\n .offset({top, left: left - 20})\r\n .text(end);\r\n }\r\n }\r\n }\r\n });\r\n }, function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n $(\".\" + clazz).css(\"background-color\", \"\");\r\n $(this).closest(\".problemindexholder\").find(\".testCaseMarker_\" + end).hide();\r\n }\r\n }\r\n });\r\n });\r\n\r\n });\r\n</script>\r\n\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 05:38:20</span> (j3).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/73366/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/73366/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/73366/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/73366/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-73366.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'8122c46f0cb69d61',t:'MTY5NjY0NjMwMC4wOTEwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"},"long_tags":{"kind":"string","value":"[\"Dynamic programming\", \"Prefix- and Z-functions, suffix structures, Knuth\\u2013Morris\\u2013Pratt algorithm, etc\", \"Two pointers\"]"},"short_tags":{"kind":"string","value":"[\"dp\", \"strings\", \"two pointers\", \"*2000\"]"},"tutorial_link":{"kind":"string","value":""},"tutorial_page":{"kind":"string","value":""}}},{"rowIdx":1952,"cells":{"problem_id":{"kind":"string","value":"386D"},"contest":{"kind":"string","value":"386"},"problem":{"kind":"string","value":"D"},"lang":{"kind":"string","value":"en"},"problem_title":{"kind":"string","value":"D. Game with Points"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">D. Game with Points</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>You are playing the following game. There are <span class=\"tex-span\"><i>n</i></span> points on a plane. They are the vertices of a regular <span class=\"tex-span\"><i>n</i></span>-polygon. Points are labeled with integer numbers from <span class=\"tex-span\">1</span> to <span class=\"tex-span\"><i>n</i></span>. Each pair of distinct points is connected by a diagonal, which is colored in one of 26 colors. Points are denoted by lowercase English letters. There are three stones positioned on three distinct vertices. All stones are the same. With one move you can move the stone to another free vertex along some diagonal. The color of this diagonal must be the same as the color of the diagonal, connecting another two stones. </p><p>Your goal is to move stones in such way that the only vertices occupied by stones are <span class=\"tex-span\">1</span>, <span class=\"tex-span\">2</span> and <span class=\"tex-span\">3</span>. You must achieve such position using minimal number of moves. Write a program which plays this game in an optimal way.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>In the first line there is one integer <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">3 ≤ <i>n</i> ≤ 70</span>) — the number of points. In the second line there are three space-separated integer from <span class=\"tex-span\">1</span> to <span class=\"tex-span\"><i>n</i></span> — numbers of vertices, where stones are initially located.</p><p>Each of the following <span class=\"tex-span\"><i>n</i></span> lines contains <span class=\"tex-span\"><i>n</i></span> symbols — the matrix denoting the colors of the diagonals. Colors are denoted by lowercase English letters. The symbol <span class=\"tex-span\"><i>j</i></span> of line <span class=\"tex-span\"><i>i</i></span> denotes the color of diagonal between points <span class=\"tex-span\"><i>i</i></span> and <span class=\"tex-span\"><i>j</i></span>. Matrix is symmetric, so <span class=\"tex-span\"><i>j</i></span>-th symbol of <span class=\"tex-span\"><i>i</i></span>-th line is equal to <span class=\"tex-span\"><i>i</i></span>-th symbol of <span class=\"tex-span\"><i>j</i></span>-th line. Main diagonal is filled with '<span class=\"tex-font-style-tt\">*</span>' symbols because there is no diagonal, connecting point to itself.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>If there is no way to put stones on vertices <span class=\"tex-span\">1</span>, <span class=\"tex-span\">2</span> and <span class=\"tex-span\">3</span>, print <span class=\"tex-font-style-tt\">-1</span> on a single line. Otherwise, on the first line print minimal required number of moves and in the next lines print the description of each move, one move per line. To describe a move print two integers. The point from which to remove the stone, and the point to which move the stone. If there are several optimal solutions, print any of them.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>4<br/>2 3 4<br/>*aba<br/>a*ab<br/>ba*b<br/>abb*<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1<br/>4 1<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>4<br/>2 3 4<br/>*abc<br/>a*ab<br/>ba*b<br/>cbb*<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>-1<br/></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>In the first example we can move stone from point <span class=\"tex-span\">4</span> to point <span class=\"tex-span\">1</span> because this points are connected by the diagonal of color '<span class=\"tex-font-style-tt\">a</span>' and the diagonal connection point <span class=\"tex-span\">2</span> and <span class=\"tex-span\">3</span>, where the other stones are located, are connected by the diagonal of the same color. After that stones will be on the points <span class=\"tex-span\">1</span>, <span class=\"tex-span\">2</span> and <span class=\"tex-span\">3</span>.</p></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"818250e9fbff159a7b21657343d6682c\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - D - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"44c637d2380d90080d2a194660db8ac80257ad59\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - D - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/73366/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/73366/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/73366/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/73366/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/73366/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/73366/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/73366/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/73366/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/73366/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/73366/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/73366/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/73366/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/73366/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/73366/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/sidebar-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/a037fe51637846d9c7c725713cd840ea/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='818250e9fbff159a7b21657343d6682c'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/73366/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/73366/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fcontest%2F386%2Fproblem%2FD%3Flocale%3Den\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"current\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='818250e9fbff159a7b21657343d6682c'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:100%;\"><a style=\"color: black\" href=\"/contest/386\">Testing Round 9</a></th>\n </tr>\n <tr>\n <td class=\"left bottom\" colspan=\"1\"><span class=\"contest-state-phase\">Finished</span></td>\n </tr>\n </tbody>\n </table>\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Practice?\n <div class=\"top-links\">\n </div>\n </div>\n<div>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Want to solve the contest problems after the official contest ends? Just register for practice and you will be able to submit solutions.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"\" method=\"post\"><input type='hidden' name='csrf_token' value='818250e9fbff159a7b21657343d6682c'/>\r\n <input type=\"hidden\" name=\"action\" value=\"registerForPractice\"/>\r\n <input type=\"submit\" name=\"submit\" value=\"Register for practice\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div> \r\n</div>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox ContestVirtualFrame borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Virtual participation <i class=\"sidebar-caption-icon las la-angle-down\"></i>\r\n\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\" \"\r\n\r\n data-page-url=\"/data/sidebarFrames\"\r\n\r\n>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests.\n\nIf you've seen these problems, a virtual contest is not for you - solve these problems in the archive.\n\nIf you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.\n\nNever use someone else's code, read the tutorials or communicate with other person during a virtual contest.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"/contest/386/virtual\" method=\"get\">\r\n <input type=\"submit\" name=\"submit\" value=\"Start virtual contest\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div>\r\n</div>\r\n <script>\r\n $(function () {\r\n $(\".ContestVirtualFrame .sidebar-caption-icon\").click(function() {\r\n $(this).toggleClass(\"la-angle-down la-angle-right\");\r\n const $target = $(this).parent().next();\r\n $target.toggle();\r\n const dataPageUrl = $target.attr(\"data-page-url\");\r\n const collapsed = $(this).hasClass(\"la-angle-right\");\r\n const params = {\r\n action: \"setCollapsed\",\r\n sidebarFrameSimpleClassName: \"ContestVirtualFrame\",\r\n collapsed\r\n };\r\n $.each($target[0].attributes, function(i, a) {\r\n const name = a.name;\r\n if (name.startsWith(\"data-extra-key-\")) {\r\n const key = a.value;\r\n const keyIndex = parseInt(name.substring(\"data-extra-key-\".length));\r\n const value = $target.attr(\"data-extra-value-\" + keyIndex);\r\n params[key] = value;\r\n }\r\n });\r\n $.post(dataPageUrl, params, function (result) {\r\n if (result[\"success\"] !== \"true\") {\r\n Codeforces.showMessage(\"Failed to save collapsed state.\");\r\n }\r\n }, \"json\");\r\n return false;\r\n });\r\n })\r\n </script>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Problem tags\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Dynamic programming\">\r\n dp\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Graphs\">\r\n graphs\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Implementation problems, programming technics, simulation\">\r\n implementation\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Shortest paths on weighted and unweighted graphs\">\r\n shortest paths\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Difficulty\">\r\n *2100\r\n</span>\r\n </div>\n <div style=\"clear:both;text-align:right;font-size:1.1rem;\">\r\n <span title=\"Please login into the Codeforces\" class=\"notice\">No tag edit access</span>\r\n </div>\r\n</div>\r\n </div>\n\r\n<form id=\"addTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='818250e9fbff159a7b21657343d6682c'/>\r\n <input name=\"action\" type=\"hidden\" value=\"addTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"5689\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<form id=\"removeTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='818250e9fbff159a7b21657343d6682c'/>\r\n <input name=\"action\" type=\"hidden\" value=\"removeTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"5689\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<script type=\"text/javascript\">\r\n $(\".tag-box img\").click(function () {\r\n var tagName = $(this).attr(\"value\");\r\n Codeforces.confirm(\"Are you sure you want to remove this tag?\", function () {\r\n $(\"#removeTagForm input[name=tagName]\").val(tagName);\r\n $(\"#removeTagForm\").submit();\r\n }, function () {\r\n }, \"Yes\", \"No\");\r\n });\r\n\r\n $(\"#addTagLink\").click(function () {\r\n $(this).hide();\r\n $(\"#addTagLabel\").show();\r\n return false;\r\n });\r\n\r\n $(\"#addTagSelect\").change(function () {\r\n var tagName = $(this).val();\r\n if (tagName === \"\") {\r\n $(\"#addTagLabel\").hide();\r\n $(\"#addTagLink\").show();\r\n } else {\r\n $(\"#addTagForm input[name=tagName]\").val(tagName);\r\n $(\"#addTagForm\").submit();\r\n }\r\n });\r\n</script>\r\n\r\n<style type=\"text/css\">\r\n#new-resource-form tr td {\r\npadding-top: 0.5em;\r\n}\r\n#new-resource-form input:not([type=\"submit\"]) {\r\nfont-size: 0.8em;\r\n}\r\n#new-resource-form select {\r\nfont-size: 0.8em;\r\n}\r\n.new-resource-error {\r\nfont-size: 0.8em;\r\n}\r\n.resource-locale {\r\ncolor: #666;\r\nfont-family: Consolas, \"Andale Mono WT\", \"Andale Mono\", \"Lucida Console\", \"Lucida Sans Typewriter\", \"DejaVu Sans Mono\", \"Bitstream Vera Sans Mono\", \"Liberation Mono\", \"Nimbus Mono L\", Monaco, \"Courier New\", Courier, monospace;\r\n}\r\n</style>\r\n<div class=\"roundbox sidebox sidebar-menu borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Contest materials\n<div class=\"top-links\">\n</div>\n</div>\n<ul>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/10422\" title=\"Testing Round #9\" target=\"_blank\">Testing Round #9</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"2159:2160\" resourceName=\"Announcement\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n</ul>\r\n</div></div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li class=\"current selectedLava\"><a\r\n href=\"/contest/386\">Problems</a></li>\r\n <li><a\r\n href=\"/contest/386/submit\">Submit Code</a></li>\r\n <li><a\r\n href=\"/contest/386/my\">My Submissions</a></li>\r\n <li><a\r\n href=\"/contest/386/status\">Status</a></li>\r\n <li><a\r\n href=\"/contest/386/hacks\">Hacks</a></li>\r\n <li><a\r\n href=\"/contest/386/room/1\">Room</a></li>\r\n <li><a\r\n href=\"/contest/386/standings\">Standings</a></li>\r\n <li><a\r\n href=\"/contest/386/customtest\">Custom Invocation</a></li>\r\n</ul>\r\n</div>\n\r\n <style>\r\n #facebox .content:has(.diff-popup) {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n }\r\n\r\n .testCaseMarker {\r\n position: absolute;\r\n font-weight: bold;\r\n font-size: 1rem;\r\n }\r\n\r\n .diff-popup {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n display: none;\r\n overflow: auto;\r\n }\r\n\r\n .input-output-copier {\r\n font-size: 1.2rem;\r\n float: right;\r\n color: #888 !important;\r\n cursor: pointer;\r\n border: 1px solid rgb(185, 185, 185);\r\n padding: 3px;\r\n margin: 1px;\r\n line-height: 1.1rem;\r\n text-transform: none;\r\n }\r\n\r\n .input-output-copier:hover {\r\n background-color: #def;\r\n }\r\n\r\n .test-explanation textarea {\r\n width: 100%;\r\n height: 1.5em;\r\n }\r\n\r\n .pending-submission-message {\r\n color: darkorange !important;\r\n }\r\n </style>\r\n <script>\r\n const OPENING_SPACE = String.fromCharCode(1001);\r\n const CLOSING_SPACE = String.fromCharCode(1002);\r\n\r\n const nodeToText = function (node, pre) {\r\n let result = [];\r\n\r\n if (node.tagName === \"SCRIPT\" || node.tagName === \"math\"\r\n || (node.classList && node.classList.contains(\"input-output-copier\")))\r\n return [];\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(OPENING_SPACE);\r\n }\r\n\r\n if (node.nodeType === Node.TEXT_NODE) {\r\n let s = node.textContent;\r\n if (!pre) {\r\n s = s.replace(/\\s+/g, \" \");\r\n }\r\n if (s.length > 0) {\r\n result.push(s);\r\n }\r\n }\r\n\r\n if (pre && node.tagName === \"BR\") {\r\n result.push(\"\\n\");\r\n }\r\n\r\n node.childNodes.forEach(function (child) {\r\n result.push(nodeToText(child, node.tagName === \"PRE\").join(\"\"));\r\n });\r\n\r\n if (node.tagName === \"DIV\"\r\n || node.tagName === \"P\"\r\n || node.tagName === \"PRE\"\r\n || node.tagName === \"UL\"\r\n || node.tagName === \"LI\"\r\n ) {\r\n result.push(\"\\n\");\r\n }\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(CLOSING_SPACE);\r\n }\r\n\r\n return result;\r\n }\r\n\r\n const isSpecial = function (c) {\r\n return c === ',' || c === '.' || c === ';' || c === ')' || c === ' ';\r\n }\r\n\r\n const convertStatementToText = function(statmentNode) {\r\n const text = nodeToText(statmentNode, false).join(\"\").replace(/ +/g, \" \").replace(/\\n\\n+/g, \"\\n\\n\");\r\n let result = [];\r\n for (let i = 0; i < text.length; i++) {\r\n const c = text.charAt(i);\r\n if (c === OPENING_SPACE) {\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"D\" data-uuid=\"ps_273b2bb98e1cb372a5ebbb13a862a70c8c3a62bc\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">D. Game with Points</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>You are playing the following game. There are <span class=\"tex-span\"><i>n</i></span> points on a plane. They are the vertices of a regular <span class=\"tex-span\"><i>n</i></span>-polygon. Points are labeled with integer numbers from <span class=\"tex-span\">1</span> to <span class=\"tex-span\"><i>n</i></span>. Each pair of distinct points is connected by a diagonal, which is colored in one of 26 colors. Points are denoted by lowercase English letters. There are three stones positioned on three distinct vertices. All stones are the same. With one move you can move the stone to another free vertex along some diagonal. The color of this diagonal must be the same as the color of the diagonal, connecting another two stones. </p><p>Your goal is to move stones in such way that the only vertices occupied by stones are <span class=\"tex-span\">1</span>, <span class=\"tex-span\">2</span> and <span class=\"tex-span\">3</span>. You must achieve such position using minimal number of moves. Write a program which plays this game in an optimal way.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>In the first line there is one integer <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">3 ≤ <i>n</i> ≤ 70</span>) — the number of points. In the second line there are three space-separated integer from <span class=\"tex-span\">1</span> to <span class=\"tex-span\"><i>n</i></span> — numbers of vertices, where stones are initially located.</p><p>Each of the following <span class=\"tex-span\"><i>n</i></span> lines contains <span class=\"tex-span\"><i>n</i></span> symbols — the matrix denoting the colors of the diagonals. Colors are denoted by lowercase English letters. The symbol <span class=\"tex-span\"><i>j</i></span> of line <span class=\"tex-span\"><i>i</i></span> denotes the color of diagonal between points <span class=\"tex-span\"><i>i</i></span> and <span class=\"tex-span\"><i>j</i></span>. Matrix is symmetric, so <span class=\"tex-span\"><i>j</i></span>-th symbol of <span class=\"tex-span\"><i>i</i></span>-th line is equal to <span class=\"tex-span\"><i>i</i></span>-th symbol of <span class=\"tex-span\"><i>j</i></span>-th line. Main diagonal is filled with '<span class=\"tex-font-style-tt\">*</span>' symbols because there is no diagonal, connecting point to itself.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>If there is no way to put stones on vertices <span class=\"tex-span\">1</span>, <span class=\"tex-span\">2</span> and <span class=\"tex-span\">3</span>, print <span class=\"tex-font-style-tt\">-1</span> on a single line. Otherwise, on the first line print minimal required number of moves and in the next lines print the description of each move, one move per line. To describe a move print two integers. The point from which to remove the stone, and the point to which move the stone. If there are several optimal solutions, print any of them.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>4<br />2 3 4<br />*aba<br />a*ab<br />ba*b<br />abb*<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1<br />4 1<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>4<br />2 3 4<br />*abc<br />a*ab<br />ba*b<br />cbb*<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>-1<br /></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>In the first example we can move stone from point <span class=\"tex-span\">4</span> to point <span class=\"tex-span\">1</span> because this points are connected by the diagonal of color '<span class=\"tex-font-style-tt\">a</span>' and the diagonal connection point <span class=\"tex-span\">2</span> and <span class=\"tex-span\">3</span>, where the other stones are located, are connected by the diagonal of the same color. After that stones will be on the points <span class=\"tex-span\">1</span>, <span class=\"tex-span\">2</span> and <span class=\"tex-span\">3</span>.</p></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=D]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== statementText) {\r\n $problem.find(\".diff-notifier\").show();\r\n\r\n $problem.find(\".diff-notifier-close\").click(function() {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n $problem.find(\".diff-notifier\").hide();\r\n });\r\n\r\n $problem.find(\"a.view-changes\").click(function() {\r\n $.post(\"/data/diff\", {action: \"getDiff\", a: previousStatementText, b: statementText}, function (result) {\r\n if (result[\"success\"] === \"true\") {\r\n Codeforces.facebox(\".diff-popup\", \"//codeforces.org/s/73366\");\r\n $(\"#facebox .diff-popup\").html(result[\"diff\"]);\r\n }\r\n }, \"json\");\r\n });\r\n }\r\n } else {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n }\r\n });\r\n });\r\n </script>\r\n\r\n\r\n<script type=\"text/javascript\">\r\n $(document).ready(function () {\r\n window.changedTests = new Set();\r\n\r\n function endsWith(string, suffix) {\r\n return string.indexOf(suffix, string.length - suffix.length) !== -1;\r\n }\r\n\r\n const inputFileDiv = $(\"div.input-file\");\r\n const inputFile = inputFileDiv.text();\r\n const outputFileDiv = $(\"div.output-file\");\r\n const outputFile = outputFileDiv.text();\r\n\r\n\r\n if (!endsWith(inputFile, \"standard input\")\r\n && !endsWith(inputFile, \"standard input\")) {\r\n inputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n if (!endsWith(outputFile, \"standard output\")\r\n && !endsWith(outputFile, \"standard output\")) {\r\n outputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n const titleDiv = $(\"div.header div.title\");\r\n\r\n\r\n\r\n String.prototype.replaceAll = function (search, replace) {\r\n return this.split(search).join(replace);\r\n };\r\n\r\n $(\".sample-test .title\").each(function () {\r\n const preId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n const cpyId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n\r\n $(this).parent().find(\"pre\").attr(\"id\", preId);\r\n const $copy = $(\"<div title='Copy' data-clipboard-target='#\" + preId + \"' id='\" + cpyId + \"' class='input-output-copier'>Copy</div>\");\r\n $(this).append($copy);\r\n\r\n const clipboard = new Clipboard('#' + cpyId, {\r\n text: function (trigger) {\r\n const pre = document.querySelector('#' + preId);\r\n const lines = pre.querySelectorAll(\".test-example-line\");\r\n return Codeforces.filterClipboardText(pre.innerText, lines.length);\r\n }\r\n });\r\n\r\n const isInput = $(this).parent().hasClass(\"input\");\r\n\r\n clipboard.on('success', function (e) {\r\n if (isInput) {\r\n Codeforces.showMessage(\"The example input has been copied into the clipboard\");\r\n } else {\r\n Codeforces.showMessage(\"The example output has been copied into the clipboard\");\r\n }\r\n e.clearSelection();\r\n });\r\n });\r\n\r\n $(\".test-form-item input\").change(function () {\r\n addPendingSubmissionMessage($($(this).closest(\"form\")), \"You changed the answer, do not forget to submit it if you want to save the changes\");\r\n const index = $(this).closest(\".problemindexholder\").attr(\"problemindex\");\r\n let test = \"\";\r\n $(this).closest(\"form input\").each(function () {\r\n const test_ = $(this).attr(\"name\");\r\n if (test_ && test_.substring(0, 4) === \"test\") {\r\n test = test_;\r\n }\r\n });\r\n if (index.length > 0 && test.length > 0) {\r\n const indexTest = index + \"::\" + test;\r\n window.changedTests.add(indexTest);\r\n }\r\n });\r\n\r\n $(window).on('beforeunload', function () {\r\n if (window.changedTests.size > 0) {\r\n return 'Dialog text here';\r\n }\r\n });\r\n\r\n autosize($('.test-explanation textarea'));\r\n\r\n $(\".test-example-line\").hover(function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n let top = 1E20;\r\n let left = 1E20;\r\n let problem = $(this).closest(\".problemindexholder\");\r\n $(this).closest(\".input\").find(\".\" + clazz).css(\"background-color\", \"#FFFDE7\").each(function() {\r\n top = Math.min(top, $(this).offset().top);\r\n left = Math.min(left, $(this).offset().left);\r\n });\r\n let testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n if (testCaseMarker.length === 0) {\r\n const html = \"<div class=\\\"testCaseMarker testCaseMarker_\" + end + \" notice\\\"></div>\";\r\n problem.append($(html));\r\n testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n }\r\n if (testCaseMarker) {\r\n testCaseMarker.show()\r\n .offset({top, left: left - 20})\r\n .text(end);\r\n }\r\n }\r\n }\r\n });\r\n }, function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n $(\".\" + clazz).css(\"background-color\", \"\");\r\n $(this).closest(\".problemindexholder\").find(\".testCaseMarker_\" + end).hide();\r\n }\r\n }\r\n });\r\n });\r\n\r\n });\r\n</script>\r\n\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 05:38:21</span> (j3).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/73366/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/73366/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/73366/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/73366/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-73366.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'8122c4772a791628',t:'MTY5NjY0NjMwMS40MTgwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"},"long_tags":{"kind":"string","value":"[\"Dynamic programming\", \"Graphs\", \"Implementation problems, programming technics, simulation\", \"Shortest paths on weighted and unweighted graphs\"]"},"short_tags":{"kind":"string","value":"[\"dp\", \"graphs\", \"implementation\", \"shortest paths\", \"*2100\"]"},"tutorial_link":{"kind":"string","value":""},"tutorial_page":{"kind":"string","value":""}}},{"rowIdx":1953,"cells":{"problem_id":{"kind":"string","value":"387A"},"contest":{"kind":"string","value":"387"},"problem":{"kind":"string","value":"A"},"lang":{"kind":"string","value":"en"},"problem_title":{"kind":"string","value":"A. George and Sleep"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">A. George and Sleep</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>George woke up and saw the current time <span class=\"tex-span\"><i>s</i></span> on the digital clock. Besides, George knows that he has slept for time <span class=\"tex-span\"><i>t</i></span>. </p><p>Help George! Write a program that will, given time <span class=\"tex-span\"><i>s</i></span> and <span class=\"tex-span\"><i>t</i></span>, determine the time <span class=\"tex-span\"><i>p</i></span> when George went to bed. Note that George could have gone to bed yesterday relatively to the current time (see the second test sample). </p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains current time <span class=\"tex-span\"><i>s</i></span> as a string in the format \"<span class=\"tex-font-style-tt\">hh:mm</span>\". The second line contains time <span class=\"tex-span\"><i>t</i></span> in the format \"<span class=\"tex-font-style-tt\">hh:mm</span>\" — the duration of George's sleep. It is guaranteed that the input contains the correct time in the 24-hour format, that is, <span class=\"tex-span\">00 ≤ <i>hh</i> ≤ 23</span>, <span class=\"tex-span\">00 ≤ <i>mm</i> ≤ 59</span>.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>In the single line print time <span class=\"tex-span\"><i>p</i></span> — the time George went to bed in the format similar to the format of the time in the input.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>05:50<br/>05:44<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>00:06<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>00:00<br/>01:00<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>23:00<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>00:01<br/>00:00<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>00:01<br/></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>In the first sample George went to bed at \"<span class=\"tex-font-style-tt\">00:06</span>\". Note that you should print the time only in the format \"<span class=\"tex-font-style-tt\">00:06</span>\". That's why answers \"<span class=\"tex-font-style-tt\">0:06</span>\", \"<span class=\"tex-font-style-tt\">00:6</span>\" and others will be considered incorrect. </p><p>In the second sample, George went to bed yesterday.</p><p>In the third sample, George didn't do to bed at all.</p></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"b78c585fd2332c7222fa019d240c108b\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - A - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"1d8414af0a90e113b8a49898336bf2bc6a1719bc\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - A - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/73366/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/73366/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/73366/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/73366/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/73366/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/73366/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/73366/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/73366/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/73366/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/73366/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/73366/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/73366/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/73366/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/73366/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/sidebar-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/a037fe51637846d9c7c725713cd840ea/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='b78c585fd2332c7222fa019d240c108b'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/73366/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/73366/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fcontest%2F387%2Fproblem%2FA%3Flocale%3Den\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"current\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='b78c585fd2332c7222fa019d240c108b'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:100%;\"><a style=\"color: black\" href=\"/contest/387\">Codeforces Round 227 (Div. 2)</a></th>\n </tr>\n <tr>\n <td class=\"left bottom\" colspan=\"1\"><span class=\"contest-state-phase\">Finished</span></td>\n </tr>\n </tbody>\n </table>\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Practice?\n <div class=\"top-links\">\n </div>\n </div>\n<div>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Want to solve the contest problems after the official contest ends? Just register for practice and you will be able to submit solutions.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"\" method=\"post\"><input type='hidden' name='csrf_token' value='b78c585fd2332c7222fa019d240c108b'/>\r\n <input type=\"hidden\" name=\"action\" value=\"registerForPractice\"/>\r\n <input type=\"submit\" name=\"submit\" value=\"Register for practice\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div> \r\n</div>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox ContestVirtualFrame borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Virtual participation <i class=\"sidebar-caption-icon las la-angle-down\"></i>\r\n\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\" \"\r\n\r\n data-page-url=\"/data/sidebarFrames\"\r\n\r\n>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests.\n\nIf you've seen these problems, a virtual contest is not for you - solve these problems in the archive.\n\nIf you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.\n\nNever use someone else's code, read the tutorials or communicate with other person during a virtual contest.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"/contest/387/virtual\" method=\"get\">\r\n <input type=\"submit\" name=\"submit\" value=\"Start virtual contest\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div>\r\n</div>\r\n <script>\r\n $(function () {\r\n $(\".ContestVirtualFrame .sidebar-caption-icon\").click(function() {\r\n $(this).toggleClass(\"la-angle-down la-angle-right\");\r\n const $target = $(this).parent().next();\r\n $target.toggle();\r\n const dataPageUrl = $target.attr(\"data-page-url\");\r\n const collapsed = $(this).hasClass(\"la-angle-right\");\r\n const params = {\r\n action: \"setCollapsed\",\r\n sidebarFrameSimpleClassName: \"ContestVirtualFrame\",\r\n collapsed\r\n };\r\n $.each($target[0].attributes, function(i, a) {\r\n const name = a.name;\r\n if (name.startsWith(\"data-extra-key-\")) {\r\n const key = a.value;\r\n const keyIndex = parseInt(name.substring(\"data-extra-key-\".length));\r\n const value = $target.attr(\"data-extra-value-\" + keyIndex);\r\n params[key] = value;\r\n }\r\n });\r\n $.post(dataPageUrl, params, function (result) {\r\n if (result[\"success\"] !== \"true\") {\r\n Codeforces.showMessage(\"Failed to save collapsed state.\");\r\n }\r\n }, \"json\");\r\n return false;\r\n });\r\n })\r\n </script>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Problem tags\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Implementation problems, programming technics, simulation\">\r\n implementation\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Difficulty\">\r\n *900\r\n</span>\r\n </div>\n <div style=\"clear:both;text-align:right;font-size:1.1rem;\">\r\n <span title=\"Please login into the Codeforces\" class=\"notice\">No tag edit access</span>\r\n </div>\r\n</div>\r\n </div>\n\r\n<form id=\"addTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='b78c585fd2332c7222fa019d240c108b'/>\r\n <input name=\"action\" type=\"hidden\" value=\"addTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"6206\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<form id=\"removeTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='b78c585fd2332c7222fa019d240c108b'/>\r\n <input name=\"action\" type=\"hidden\" value=\"removeTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"6206\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<script type=\"text/javascript\">\r\n $(\".tag-box img\").click(function () {\r\n var tagName = $(this).attr(\"value\");\r\n Codeforces.confirm(\"Are you sure you want to remove this tag?\", function () {\r\n $(\"#removeTagForm input[name=tagName]\").val(tagName);\r\n $(\"#removeTagForm\").submit();\r\n }, function () {\r\n }, \"Yes\", \"No\");\r\n });\r\n\r\n $(\"#addTagLink\").click(function () {\r\n $(this).hide();\r\n $(\"#addTagLabel\").show();\r\n return false;\r\n });\r\n\r\n $(\"#addTagSelect\").change(function () {\r\n var tagName = $(this).val();\r\n if (tagName === \"\") {\r\n $(\"#addTagLabel\").hide();\r\n $(\"#addTagLink\").show();\r\n } else {\r\n $(\"#addTagForm input[name=tagName]\").val(tagName);\r\n $(\"#addTagForm\").submit();\r\n }\r\n });\r\n</script>\r\n\r\n<style type=\"text/css\">\r\n#new-resource-form tr td {\r\npadding-top: 0.5em;\r\n}\r\n#new-resource-form input:not([type=\"submit\"]) {\r\nfont-size: 0.8em;\r\n}\r\n#new-resource-form select {\r\nfont-size: 0.8em;\r\n}\r\n.new-resource-error {\r\nfont-size: 0.8em;\r\n}\r\n.resource-locale {\r\ncolor: #666;\r\nfont-family: Consolas, \"Andale Mono WT\", \"Andale Mono\", \"Lucida Console\", \"Lucida Sans Typewriter\", \"DejaVu Sans Mono\", \"Bitstream Vera Sans Mono\", \"Liberation Mono\", \"Nimbus Mono L\", Monaco, \"Courier New\", Courier, monospace;\r\n}\r\n</style>\r\n<div class=\"roundbox sidebox sidebar-menu borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Contest materials\n<div class=\"top-links\">\n</div>\n</div>\n<ul>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/10569\" title=\"Codeforces Round #227 (Div. 2)\" target=\"_blank\">Announcement</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"2176:2182\" resourceName=\"Announcement\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/10583\" title=\"Editorial Codeforces Round #227 (Div. 2)\" target=\"_blank\">Tutorial</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"2177:2183\" resourceName=\"Tutorial\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n</ul>\r\n</div></div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li class=\"current selectedLava\"><a\r\n href=\"/contest/387\">Problems</a></li>\r\n <li><a\r\n href=\"/contest/387/submit\">Submit Code</a></li>\r\n <li><a\r\n href=\"/contest/387/my\">My Submissions</a></li>\r\n <li><a\r\n href=\"/contest/387/status\">Status</a></li>\r\n <li><a\r\n href=\"/contest/387/hacks\">Hacks</a></li>\r\n <li><a\r\n href=\"/contest/387/room/1\">Room</a></li>\r\n <li><a\r\n href=\"/contest/387/standings\">Standings</a></li>\r\n <li><a\r\n href=\"/contest/387/customtest\">Custom Invocation</a></li>\r\n</ul>\r\n</div>\n\r\n <style>\r\n #facebox .content:has(.diff-popup) {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n }\r\n\r\n .testCaseMarker {\r\n position: absolute;\r\n font-weight: bold;\r\n font-size: 1rem;\r\n }\r\n\r\n .diff-popup {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n display: none;\r\n overflow: auto;\r\n }\r\n\r\n .input-output-copier {\r\n font-size: 1.2rem;\r\n float: right;\r\n color: #888 !important;\r\n cursor: pointer;\r\n border: 1px solid rgb(185, 185, 185);\r\n padding: 3px;\r\n margin: 1px;\r\n line-height: 1.1rem;\r\n text-transform: none;\r\n }\r\n\r\n .input-output-copier:hover {\r\n background-color: #def;\r\n }\r\n\r\n .test-explanation textarea {\r\n width: 100%;\r\n height: 1.5em;\r\n }\r\n\r\n .pending-submission-message {\r\n color: darkorange !important;\r\n }\r\n </style>\r\n <script>\r\n const OPENING_SPACE = String.fromCharCode(1001);\r\n const CLOSING_SPACE = String.fromCharCode(1002);\r\n\r\n const nodeToText = function (node, pre) {\r\n let result = [];\r\n\r\n if (node.tagName === \"SCRIPT\" || node.tagName === \"math\"\r\n || (node.classList && node.classList.contains(\"input-output-copier\")))\r\n return [];\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(OPENING_SPACE);\r\n }\r\n\r\n if (node.nodeType === Node.TEXT_NODE) {\r\n let s = node.textContent;\r\n if (!pre) {\r\n s = s.replace(/\\s+/g, \" \");\r\n }\r\n if (s.length > 0) {\r\n result.push(s);\r\n }\r\n }\r\n\r\n if (pre && node.tagName === \"BR\") {\r\n result.push(\"\\n\");\r\n }\r\n\r\n node.childNodes.forEach(function (child) {\r\n result.push(nodeToText(child, node.tagName === \"PRE\").join(\"\"));\r\n });\r\n\r\n if (node.tagName === \"DIV\"\r\n || node.tagName === \"P\"\r\n || node.tagName === \"PRE\"\r\n || node.tagName === \"UL\"\r\n || node.tagName === \"LI\"\r\n ) {\r\n result.push(\"\\n\");\r\n }\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(CLOSING_SPACE);\r\n }\r\n\r\n return result;\r\n }\r\n\r\n const isSpecial = function (c) {\r\n return c === ',' || c === '.' || c === ';' || c === ')' || c === ' ';\r\n }\r\n\r\n const convertStatementToText = function(statmentNode) {\r\n const text = nodeToText(statmentNode, false).join(\"\").replace(/ +/g, \" \").replace(/\\n\\n+/g, \"\\n\\n\");\r\n let result = [];\r\n for (let i = 0; i < text.length; i++) {\r\n const c = text.charAt(i);\r\n if (c === OPENING_SPACE) {\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"A\" data-uuid=\"ps_5ad9566acf38f697b974e496a6c3f20fe0aa26f7\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">A. George and Sleep</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>George woke up and saw the current time <span class=\"tex-span\"><i>s</i></span> on the digital clock. Besides, George knows that he has slept for time <span class=\"tex-span\"><i>t</i></span>. </p><p>Help George! Write a program that will, given time <span class=\"tex-span\"><i>s</i></span> and <span class=\"tex-span\"><i>t</i></span>, determine the time <span class=\"tex-span\"><i>p</i></span> when George went to bed. Note that George could have gone to bed yesterday relatively to the current time (see the second test sample). </p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains current time <span class=\"tex-span\"><i>s</i></span> as a string in the format "<span class=\"tex-font-style-tt\">hh:mm</span>". The second line contains time <span class=\"tex-span\"><i>t</i></span> in the format "<span class=\"tex-font-style-tt\">hh:mm</span>" — the duration of George's sleep. It is guaranteed that the input contains the correct time in the 24-hour format, that is, <span class=\"tex-span\">00 ≤ <i>hh</i> ≤ 23</span>, <span class=\"tex-span\">00 ≤ <i>mm</i> ≤ 59</span>.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>In the single line print time <span class=\"tex-span\"><i>p</i></span> — the time George went to bed in the format similar to the format of the time in the input.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>05:50<br />05:44<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>00:06<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>00:00<br />01:00<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>23:00<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>00:01<br />00:00<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>00:01<br /></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>In the first sample George went to bed at "<span class=\"tex-font-style-tt\">00:06</span>". Note that you should print the time only in the format "<span class=\"tex-font-style-tt\">00:06</span>". That's why answers "<span class=\"tex-font-style-tt\">0:06</span>", "<span class=\"tex-font-style-tt\">00:6</span>" and others will be considered incorrect. </p><p>In the second sample, George went to bed yesterday.</p><p>In the third sample, George didn't do to bed at all.</p></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=A]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== statementText) {\r\n $problem.find(\".diff-notifier\").show();\r\n\r\n $problem.find(\".diff-notifier-close\").click(function() {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n $problem.find(\".diff-notifier\").hide();\r\n });\r\n\r\n $problem.find(\"a.view-changes\").click(function() {\r\n $.post(\"/data/diff\", {action: \"getDiff\", a: previousStatementText, b: statementText}, function (result) {\r\n if (result[\"success\"] === \"true\") {\r\n Codeforces.facebox(\".diff-popup\", \"//codeforces.org/s/73366\");\r\n $(\"#facebox .diff-popup\").html(result[\"diff\"]);\r\n }\r\n }, \"json\");\r\n });\r\n }\r\n } else {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n }\r\n });\r\n });\r\n </script>\r\n\r\n\r\n<script type=\"text/javascript\">\r\n $(document).ready(function () {\r\n window.changedTests = new Set();\r\n\r\n function endsWith(string, suffix) {\r\n return string.indexOf(suffix, string.length - suffix.length) !== -1;\r\n }\r\n\r\n const inputFileDiv = $(\"div.input-file\");\r\n const inputFile = inputFileDiv.text();\r\n const outputFileDiv = $(\"div.output-file\");\r\n const outputFile = outputFileDiv.text();\r\n\r\n\r\n if (!endsWith(inputFile, \"standard input\")\r\n && !endsWith(inputFile, \"standard input\")) {\r\n inputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n if (!endsWith(outputFile, \"standard output\")\r\n && !endsWith(outputFile, \"standard output\")) {\r\n outputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n const titleDiv = $(\"div.header div.title\");\r\n\r\n\r\n\r\n String.prototype.replaceAll = function (search, replace) {\r\n return this.split(search).join(replace);\r\n };\r\n\r\n $(\".sample-test .title\").each(function () {\r\n const preId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n const cpyId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n\r\n $(this).parent().find(\"pre\").attr(\"id\", preId);\r\n const $copy = $(\"<div title='Copy' data-clipboard-target='#\" + preId + \"' id='\" + cpyId + \"' class='input-output-copier'>Copy</div>\");\r\n $(this).append($copy);\r\n\r\n const clipboard = new Clipboard('#' + cpyId, {\r\n text: function (trigger) {\r\n const pre = document.querySelector('#' + preId);\r\n const lines = pre.querySelectorAll(\".test-example-line\");\r\n return Codeforces.filterClipboardText(pre.innerText, lines.length);\r\n }\r\n });\r\n\r\n const isInput = $(this).parent().hasClass(\"input\");\r\n\r\n clipboard.on('success', function (e) {\r\n if (isInput) {\r\n Codeforces.showMessage(\"The example input has been copied into the clipboard\");\r\n } else {\r\n Codeforces.showMessage(\"The example output has been copied into the clipboard\");\r\n }\r\n e.clearSelection();\r\n });\r\n });\r\n\r\n $(\".test-form-item input\").change(function () {\r\n addPendingSubmissionMessage($($(this).closest(\"form\")), \"You changed the answer, do not forget to submit it if you want to save the changes\");\r\n const index = $(this).closest(\".problemindexholder\").attr(\"problemindex\");\r\n let test = \"\";\r\n $(this).closest(\"form input\").each(function () {\r\n const test_ = $(this).attr(\"name\");\r\n if (test_ && test_.substring(0, 4) === \"test\") {\r\n test = test_;\r\n }\r\n });\r\n if (index.length > 0 && test.length > 0) {\r\n const indexTest = index + \"::\" + test;\r\n window.changedTests.add(indexTest);\r\n }\r\n });\r\n\r\n $(window).on('beforeunload', function () {\r\n if (window.changedTests.size > 0) {\r\n return 'Dialog text here';\r\n }\r\n });\r\n\r\n autosize($('.test-explanation textarea'));\r\n\r\n $(\".test-example-line\").hover(function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n let top = 1E20;\r\n let left = 1E20;\r\n let problem = $(this).closest(\".problemindexholder\");\r\n $(this).closest(\".input\").find(\".\" + clazz).css(\"background-color\", \"#FFFDE7\").each(function() {\r\n top = Math.min(top, $(this).offset().top);\r\n left = Math.min(left, $(this).offset().left);\r\n });\r\n let testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n if (testCaseMarker.length === 0) {\r\n const html = \"<div class=\\\"testCaseMarker testCaseMarker_\" + end + \" notice\\\"></div>\";\r\n problem.append($(html));\r\n testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n }\r\n if (testCaseMarker) {\r\n testCaseMarker.show()\r\n .offset({top, left: left - 20})\r\n .text(end);\r\n }\r\n }\r\n }\r\n });\r\n }, function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n $(\".\" + clazz).css(\"background-color\", \"\");\r\n $(this).closest(\".problemindexholder\").find(\".testCaseMarker_\" + end).hide();\r\n }\r\n }\r\n });\r\n });\r\n\r\n });\r\n</script>\r\n\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 05:38:22</span> (j3).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/73366/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/73366/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/73366/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/73366/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-73366.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'8122c47f89cb9dab',t:'MTY5NjY0NjMwMi44MDEwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"},"long_tags":{"kind":"string","value":"[\"Implementation problems, programming technics, simulation\"]"},"short_tags":{"kind":"string","value":"[\"implementation\", \"*900\"]"},"tutorial_link":{"kind":"string","value":"https://codeforces.com/blog/entry/10583"},"tutorial_page":{"kind":"string","value":"\r\n\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"36a5cb4572cb122db333ec3b9f88364a\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"h1\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Editorial Codeforces Round #227 (Div. 2) - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n \n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Editorial Codeforces Round #227 (Div. 2) - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/81027/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/81027/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/81027/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/81027/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/81027/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/81027/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/81027/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/81027/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/81027/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/81027/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/81027/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/81027/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/81027/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/81027/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/573cedc6b04c15481941f418269f4057/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='36a5cb4572cb122db333ec3b9f88364a'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/81027/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fblog%2Fentry%2F10583\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='36a5cb4572cb122db333ec3b9f88364a'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Pay attention\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n <div style=\"text-align:center;border-bottom: 1px solid rgb(185, 185, 185);margin:0 -0.5em 0.5em -0.5em;padding: 0 1em 0.5em 1em;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 1, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:51:56</span><br/><a href=\"/contestRegistration/1876\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n <div style=\"text-align:center;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 2, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:51:56</span><br/><a href=\"/contestRegistration/1877\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n\r\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div>\r\n\r\n\n <div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\n\r\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='36a5cb4572cb122db333ec3b9f88364a'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n </label>\r\n </div>\r\n <div style=\"padding: 0 1em 1em 1em;text-align:right;\">\r\n <input style=\"height:1.65em;padding:0 0.75em;\" type=\"submit\" value=\"Find\"/>\r\n </div>\r\n </form>\r\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".handleBox\").autocomplete(\"/data/handles\", {\r\n delay: 200,\r\n width: 200,\r\n selectFirst: false,\r\n matchContains: true,\r\n minChars: 3\r\n });\r\n $(\".handleForm\").attr(\"autocomplete\", \"off\").submit(function () {\r\n var link = \"/profile/userHandle\".replace(\r\n \"userHandle\", $(this).find(\".handleBox\").val()\r\n );\r\n window.location = link;\r\n return false;\r\n });\r\n });\n </script>\n\r\n\r\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Recent actions\n <div class=\"top-links\">\n </div>\n </div>\n <div class=\"recent-actions\">\r\n <ul>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/121073\">Meta Hacker Cup 2023 Round 1</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/.Danet\" title=\"Expert .Danet\" class=\"rated-user user-blue\">.Danet</a> →\r\n <a href=\"/blog/entry/121172\">[TLE on pretest1]</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\" class=\"rated-user user-red\">Pyqe</a> →\r\n <a href=\"/blog/entry/121025\">Codeforces Round #902 (Div. 1, Div. 2, based on COMPFEST 15 — Final Round)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pranshu_Pandya\" title=\"Specialist Pranshu_Pandya\" class=\"rated-user user-cyan\">Pranshu_Pandya</a> →\r\n <a href=\"/blog/entry/121171\">An Interesting Tree Problem</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/sszcdjr\" title=\"Master sszcdjr\" class=\"rated-user user-orange\">sszcdjr</a> →\r\n <a href=\"/blog/entry/119859\">Codeforces Round 896 (Div. 1, Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/119880\">It's Happening! Meta Hacker Cup 2023 Schedule</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/DaviddeGea1\" title=\"Expert DaviddeGea1\" class=\"rated-user user-blue\">DaviddeGea1</a> →\r\n <a href=\"/blog/entry/70917\">Number of ways of dividing an array into 2 parts such that sum of each part is > k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bekh\" title=\"Master Bekh\" class=\"rated-user user-orange\">Bekh</a> →\r\n <a href=\"/blog/entry/74245\">Questions and doubts regarding Aliens DP trick</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a> →\r\n <a href=\"/blog/entry/8192\">Codeforces Round #190 — Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/hocky\" title=\"Candidate Master hocky\" class=\"rated-user user-violet\">hocky</a> →\r\n <a href=\"/blog/entry/95323\">FBHC wuining uw Day? Incwease uw stacc size! (ㅅ´ ˘ `)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/liouzhou_101\" title=\"International Master liouzhou_101\" class=\"rated-user user-orange\">liouzhou_101</a> →\r\n <a href=\"/blog/entry/87598\">Editorial of Codeforces Round #700</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/yeon_gist\" title=\"Newbie yeon_gist\" class=\"rated-user user-gray\">yeon_gist</a> →\r\n <a href=\"/blog/entry/121170\">plusMinusPermutation computing error</a>\r\n <img alt=\"Text created or updated\" title=\"Text created or updated\" src=\"//codeforces.org/s/81027/images/icons/x-update-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/altforminuscontribution\" title=\"Newbie altforminuscontribution\" class=\"rated-user user-gray\">altforminuscontribution</a> →\r\n <a href=\"/blog/entry/121162\">My screen get unexpectedly big, what should I do</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/atcoder_official\" title=\"Unrated, atcoder_official\" class=\"rated-user user-black\">atcoder_official</a> →\r\n <a href=\"/blog/entry/121120\">We will hold UNIQUE VISION Programming Contest 2023 Autumn(AtCoder Beginner Contest 323)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/YouStill_DontKnowMeYet\" title=\"Candidate Master YouStill_DontKnowMeYet\" class=\"rated-user user-violet\">YouStill_DontKnowMeYet</a> →\r\n <a href=\"/blog/entry/117659\">[GYM] Al-Baath Collegiate Programming Contest 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/ankancool\" title=\"Expert ankancool\" class=\"rated-user user-blue\">ankancool</a> →\r\n <a href=\"/blog/entry/121136\">Invitation to AstroByte 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/GeZhiyuan\" title=\"Grandmaster GeZhiyuan\" class=\"rated-user user-red\">GeZhiyuan</a> →\r\n <a href=\"/blog/entry/120943\">Codeforces Round 901 (Div. 1, Div. 2) Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a> →\r\n <a href=\"/blog/entry/120772\">PSA: Increase your stack size before the Meta Hacker Cup, here's how</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/dino_merlin\" title=\"Expert dino_merlin\" class=\"rated-user user-blue\">dino_merlin</a> →\r\n <a href=\"/blog/entry/121145\">Intuitive approach for CEOI Kangaroo?</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/icecuber\" title=\"Grandmaster icecuber\" class=\"rated-user user-red\">icecuber</a> →\r\n <a href=\"/blog/entry/70018\">CSES DP section editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bn00b\" title=\"Newbie Bn00b\" class=\"rated-user user-gray\">Bn00b</a> →\r\n <a href=\"/blog/entry/98820\">[FEATURE REQUEST : ATCODER] TOPICS TAGS AND SORTING BY SOLVE COUNT</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a> →\r\n <a href=\"/blog/entry/121163\">AtCoder Regular Contest 166 Announcement</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/windva\" title=\"Grandmaster windva\" class=\"rated-user user-red\">windva</a> →\r\n <a href=\"/blog/entry/120644\">Codeforces Round 899 (Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Misa-Misa\" title=\"Expert Misa-Misa\" class=\"rated-user user-blue\">Misa-Misa</a> →\r\n <a href=\"/blog/entry/121157\">Someone please help me understand this.</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/shivam565\" title=\"Specialist shivam565\" class=\"rated-user user-cyan\">shivam565</a> →\r\n <a href=\"/blog/entry/108348\">Total number of subarrays with sum atmost k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n </ul>\r\n </div>\r\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/recent-actions\">Detailed →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n</div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li><a\r\n href=\"/profile/gridnevvvit\">gridnevvvit</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/gridnevvvit\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/gridnevvvit\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/gridnevvvit\">Submissions</a></li>\r\n <li><a\r\n href=\"/groups/with/gridnevvvit\">Groups</a></li>\r\n <li><a\r\n href=\"/contests/with/gridnevvvit\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/gridnevvvit\">Problemsetting</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/gridnevvvit\" style=\"text-decoration:none;color:black !important;\">gridnevvvit's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"10638\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/10583\"> <p>Editorial Codeforces Round #227 (Div. 2)</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/gridnevvvit\" title=\"Candidate Master gridnevvvit\" class=\"rated-user user-violet\">gridnevvvit</a>,\r\n <span class=\"format-humantime\" title=\"Jan/30/2014 22:21\">10 years ago</span>,\r\n translation,\r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><h3><a href=\"/contest/387/problem/A\" title=\"Codeforces Round 227 (Div. 2)\">387A - George and Sleep</a></h3><p>I will describe the simple solution. Let George woke up in the <span class=\"tex-span\"><i>h</i><sub class=\"lower-index\">0</sub></span> hours and <span class=\"tex-span\"><i>m</i><sub class=\"lower-index\">0</sub></span> minutes, and he slept for <span class=\"tex-span\"><i>h</i><sub class=\"lower-index\">1</sub></span> hours and <span class=\"tex-span\"><i>m</i><sub class=\"lower-index\">1</sub></span> minutes. Let's get the number <span class=\"tex-span\"><i>h</i><sub class=\"lower-index\"><i>p</i></sub> = <i>h</i><sub class=\"lower-index\">0</sub> - <i>h</i><sub class=\"lower-index\">1</sub></span> and <span class=\"tex-span\"><i>m</i><sub class=\"lower-index\"><i>p</i></sub> = <i>m</i><sub class=\"lower-index\">0</sub> - <i>m</i><sub class=\"lower-index\">1</sub></span>. If <span class=\"tex-span\"><i>m</i><sub class=\"lower-index\"><i>p</i></sub> < 0</span>, then you should add to <span class=\"tex-span\"><i>m</i><sub class=\"lower-index\"><i>p</i></sub></span> <span class=\"tex-span\">60</span> minutes and subtract from <span class=\"tex-span\"><i>h</i><sub class=\"lower-index\"><i>p</i></sub></span> one hour. After that if <span class=\"tex-span\"><i>h</i><sub class=\"lower-index\"><i>p</i></sub> < 0</span>, then add to it <span class=\"tex-span\">24</span> hours. You can print the answer in C++ by using the following line:</p> <pre><code>printf("%02d:%02d", h[p], m[p]).\n</code></pre><p>The complexity is <span class=\"tex-span\"><i>O</i>(1)</span> time and <span class=\"tex-span\"><i>O</i>(1)</span> memory.</p><p>Author's solution: <a href=\"/contest/387/submission/5850831\" title=\"Submission 5850831 by gridnevvvit\">5850831</a></p><h3><a href=\"/contest/387/problem/B\" title=\"Codeforces Round 227 (Div. 2)\">387B - George and Round</a></h3><p>Consider the number of requirements of the difficulties, which we will cover, and we will come up with and prepare new problem to cover other requirements. It is clear that if we decided to meet the <span class=\"tex-span\"><i>i</i></span> out of <span class=\"tex-span\"><i>n</i></span> requirements, it would be better to take those with minimal complexity. Let's simplify <span class=\"tex-span\"><i>i</i></span> most difficult problems to lightest requirements. If all goes well, then we update the answer by value <span class=\"tex-span\"><i>n</i> - <i>i</i></span>.</p><p>The complexity is: <span class=\"tex-span\"><i>O</i>(<i>n</i><sup class=\"upper-index\">2</sup>)</span> time / <span class=\"tex-span\"><i>O</i>(<i>n</i>)</span> memory. Note, that there is an solution with complexity <span class=\"tex-span\"><i>O</i>(<i>n</i> + <i>m</i>)</span>.</p><p>Author's solution: <a href=\"/contest/387/submission/5850888\" title=\"Submission 5850888 by gridnevvvit\">5850888</a></p><h3><a href=\"/contest/387/problem/C\" title=\"Codeforces Round 227 (Div. 2)\">387C - George and Number</a></h3><p>Let's obtain the following irreducible representation of a number <span class=\"tex-span\"><i>p</i> = <i>a</i><sub class=\"lower-index\">1</sub> + <i>a</i><sub class=\"lower-index\">2</sub> + ... + <i>a</i><sub class=\"lower-index\"><i>k</i></sub></span>, where <span class=\"tex-span\"> + </span> is a concatenation, and numbers <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> have the form <span class=\"tex-span\"><i>x</i>00..000</span> (x — is non zero digit, and after that there are only zeroes). Let's determine largest index <span class=\"tex-span\"><i>i</i></span>, such that <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub> + <i>a</i><sub class=\"lower-index\">2</sub> + ... + <i>a</i><sub class=\"lower-index\"><i>i</i> - 1</sub> < <i>a</i><sub class=\"lower-index\"><i>i</i></sub></span>. If there are no such index <span class=\"tex-span\"><i>i</i></span> then <span class=\"tex-span\"><i>i</i> = 1</span>. After that is <span class=\"tex-span\"><i>k</i> - <i>i</i> + 1</span>. You can compare numbers by using length of number and first digit. You can prove these solution as home task : )</p><p>The complexity is: <span class=\"tex-span\"><i>O</i>(<i>n</i>)</span> time / <span class=\"tex-span\"><i>O</i>(<i>n</i>)</span> memory.</p><p>Author's solution: <a href=\"/contest/387/submission/5850919\" title=\"Submission 5850919 by gridnevvvit\">5850919</a></p><h3><a href=\"/contest/387/problem/D\" title=\"Codeforces Round 227 (Div. 2)\">387D - George and Interesting Graph</a></h3><p>To solve this problem you should know about bipartite matching.</p><p>Let's consider the center of graph <span class=\"tex-span\"><i>i</i></span>. After that let's remove arcs that have form <span class=\"tex-span\">(<i>i</i>, <i>u</i>)</span> or <span class=\"tex-span\">(<i>u</i>, <i>i</i>)</span>. Let's there are <span class=\"tex-span\"><i>cntWithI</i></span> arcs of such type. Let's <span class=\"tex-span\"><i>Other</i> = <i>m</i> - <i>CntWithI</i></span> — number of other arcs.</p><p>After that we should found maximal bipartite matching on the bipartite graph. This graph has following idea: left part of this graph is indegrees of all vertexes except vertex <span class=\"tex-span\"><i>i</i></span>, right part of this graph is outdegrees of all vertexes except vertex <span class=\"tex-span\"><i>i</i></span>. Also if there an arc <span class=\"tex-span\">(<i>i</i>, <i>j</i>)</span> in our graph then in our bipartite graph there an arc <span class=\"tex-span\">(<i>i</i>, <i>j</i>)</span>, where <span class=\"tex-span\"><i>i</i></span> — vertex from left part, <span class=\"tex-span\"><i>j</i></span> — vertex from the right part. Let's size of bipartite matching on the bipartite graph equals to <span class=\"tex-span\"><i>leng</i></span>. Then answer for the current vertex <span class=\"tex-span\"><i>i</i></span> equals to <span class=\"tex-span\">2<i>n</i> - 1 - <i>cntWithI</i> + <i>Other</i> - <i>leng</i> + (<i>n</i> - 1) - <i>leng</i></span>. After that you should update global answer. Why it is correct? It is simple to understand that if we will found bipartite matching on the bipartite graph we will cover maximal number of requirements on in/out degrees. Because of that, we will remove all other arcs, except of maximal matching, and after that we will add this maximal matching to full matching by adding <span class=\"tex-span\">(<i>n</i> - 1) - <i>leng</i></span> arcs. Note, it is important, that self-loops are not forbidden. Withoud self-loops problem is very hard, I think. </p><p>The complexity is: <span class=\"tex-span\"><i>O</i>(<i>n</i><sup class=\"upper-index\">2</sup><i>m</i>)</span> time / <span class=\"tex-span\"><i>O</i>(<i>n</i> + <i>m</i>)</span> memory.</p><p><a href=\"/contest/387/submission/5850946\" title=\"Submission 5850946 by gridnevvvit\">5850946</a></p><h3><a href=\"/contest/387/problem/E\" title=\"Codeforces Round 227 (Div. 2)\">387E - George and Cards</a></h3><p>Let's calculate arrays <span class=\"tex-span\"><i>pos</i>[<i>i</i>]</span> — position of number <span class=\"tex-span\"><i>i</i></span> in permutation <span class=\"tex-span\"><i>p</i></span> and <span class=\"tex-span\"><i>need</i>[<i>i</i>]</span> — equals to one if we should remove number <span class=\"tex-span\"><i>i</i></span> from permutation <span class=\"tex-span\"><i>p</i></span>, and zero if we shouldn't remove <span class=\"tex-span\"><i>i</i></span> from permutation <span class=\"tex-span\"><i>p</i></span>. </p><p>Let's <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub>, <i>a</i><sub class=\"lower-index\">2</sub>, ..., <i>a</i><sub class=\"lower-index\"><i>n</i> - <i>k</i></sub></span> — numvers, which we should remove. It is clear to understand that we should remove these number in increasing order. It is simple to proof this statement.</p><p>Let's iterate <span class=\"tex-span\"><i>i</i></span> from to <span class=\"tex-span\">1</span> to <span class=\"tex-span\"><i>n</i></span>. Also we the current number we will have special set (set <>in с++, TreeSet in Java) of positions of non-erased numbers (which are smaller then <span class=\"tex-span\"><i>i</i></span>) of permutation. These position can create an ``obstacle'' for current position of number <span class=\"tex-span\"><i>i</i></span>. It is simple to support this special set. Also we can add to this set numbers <span class=\"tex-span\"> - 1</span> and <span class=\"tex-span\"><i>n</i></span>. Now it is easy to find length og the maximal sub-array, where current number is a minimum. You can prosess such query by using standart functions of programming language (lower and higher in Java). After that we should use Fenwick tree to determine quantity of numbers which are not removed on the maximal sub-array.</p><p>The complexity is: <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/5e7dae7c1838af7ba7570bdf02ff61029b043be6.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> time / <span class=\"tex-span\"><i>O</i>(<i>n</i>)</span> memory.</p><p>Very simple implementation on Java: <a href=\"/contest/387/submission/5850986\" title=\"Submission 5850986 by gridnevvvit\">5850986</a></p></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/387\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 227 (Div. 2)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-6883-10638\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"6883\",\n blogEntryId: \"10583\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n <div style=\"font-size: 1.1rem;line-height: 11px;\">\r\n <img style=\"vertical-align: middle;\" src=\"//codeforces.org/s/81027/images/blog/tags.png\" title=\"Tags\" alt=\"Tags\"/>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=editorial\" class=\"tag notice\" style=\"text-decoration: none;\">editorial</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=codeforces\" class=\"tag notice\" style=\"text-decoration: none;\">codeforces</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=round\" class=\"tag notice\" style=\"text-decoration: none;\">round</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=227\" class=\"tag notice\" style=\"text-decoration: none;\">227</a>\r\n </span>\r\n </div>\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-10638\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+35</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-10638\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/gridnevvvit\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/gridnevvvit\">\n gridnevvvit\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Jan/30/2014 22:21\">10 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/10583#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/10583#comments\">\n 25\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"10654\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (25)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159495\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/coolbun\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/coolbun\" title=\"Candidate Master coolbun\" class=\"rated-user user-violet\">coolbun</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/30/2014 22:54\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159495\" href=\"?#comment-159495\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159495\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"2\"\r\n data-commentUserId=\"90437\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+2</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159495\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can anyone explain the solution of problem C</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159495 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159495 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159495\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159552\" commentParentId=\"159495\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/prakhar3agrwal\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/45384/avatar/63c5e4d25f17da6b.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/prakhar3agrwal\" title=\"Expert prakhar3agrwal\" class=\"rated-user user-blue\">prakhar3agrwal</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/31/2014 14:13\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159552\" href=\"?#comment-159552\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159495\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159552\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"45384\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159552\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Well my approach to this question was different , just start from the beginning and take 2 string variables. Let the variables be g and l (for global and local resp.),now g will store the substring starting from the beginning till just before the index from where l started.Now if the next character is '0' then we are bound to include it in the local string otherwise just see that whether g>=l or not , if yes then increase ans by 1 and include l in g (g+=l) and clear l, else make ans=1, g=g+l and clear l. This is because if g<l then obviously the substring in l should occur before g in resultant substring (meaning it will be "lg" instead of "gl"). Finally print the ans........</p><p>Hope it helps.... </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159552 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159552 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159552\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159577\" commentParentId=\"159552\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/eddycael\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/52186/avatar/a0efb238d6a68050.jpg'/> </a>\n <div><a href=\"/profile/eddycael\" title=\"Specialist eddycael\" class=\"rated-user user-cyan\">eddycael</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/31/2014 20:53\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159577\" href=\"?#comment-159577\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159552\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159577\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"52186\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159577\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Hello, (sorry for my poor english) My solution traverses the string with 2 pointers and whenever it encounters a string representing a smaller number than what's left then add 1 to the answer. It is not necessary to generate any substrings... Just analyze the representation of strings of equal length. Here's my solution: <a href=\"//codeforces.com/contest/387/submission/5858084\">solutionECMC</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159577 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159577 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159577\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159740\" commentParentId=\"159577\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/prakhar3agrwal\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/45384/avatar/63c5e4d25f17da6b.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/prakhar3agrwal\" title=\"Expert prakhar3agrwal\" class=\"rated-user user-blue\">prakhar3agrwal</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2014 08:26\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159740\" href=\"?#comment-159740\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159577\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159740\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"45384\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159740\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I am not generating any substring as such , it was the concept used in my solution, my time complexity is O(n).</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159740 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159740 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159740\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159553\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/jibon_ebong_shomoy\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/107227/avatar/d1546e81b26787b3.jpg'/> </a>\n <div><a href=\"/profile/jibon_ebong_shomoy\" title=\"Specialist jibon_ebong_shomoy\" class=\"rated-user user-cyan\">jibon_ebong_shomoy</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/31/2014 14:52\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159553\" href=\"?#comment-159553\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"159553\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"159553\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"107227\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159553\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I don't understand the solution of D . can anyone explain? what to do? why the last part of answer <code>(n-1)-leng</code> for?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159553 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159553 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159553\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159566\" commentParentId=\"159553\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/gridnevvvit\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/31163/avatar/db500a30a0b0a6f1.jpg'/> </a>\n <div><a href=\"/profile/gridnevvvit\" title=\"Candidate Master gridnevvvit\" class=\"rated-user user-violet\">gridnevvvit</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/31/2014 17:12\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159566\" href=\"?#comment-159566\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159553\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159566\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"31163\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159566\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>We will add some arcs to create prefect matching in graph</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159566 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159566 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159566\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"335415\" commentParentId=\"159553\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/u33how\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/216525/avatar/a0f0155335a1dd88.jpg'/> </a>\n <div><a href=\"/profile/u33how\" title=\"Expert u33how\" class=\"rated-user user-blue\">u33how</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/04/2017 17:52\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-335415\" href=\"?#comment-335415\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159553\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"335415\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"216525\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-335415\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I think the equation came from these :</p><p>ans = 2*(n-1); // for adding the (u,i)and(i,u) edges</p><p>ans = ans — (cntWithI) ; // they were already given, so we do not need to delete them,</p><p>ans = ans+1 ; // the center must have a self loop according to problem description.</p><p>ans = ans + Others ; // delete all the extra edges;</p><p>ans = ans — leng ; // do not have to delete the matching edges</p><p>ans = ans+ (n-1) ; // add n-1 self loops</p><p>ans = ans-leng ; // 'leng' number of vertices do not need self loop; </p><p>Hope it helps somebody.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-335415 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-335415 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-335415\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159679\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/raylee\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/135528/avatar/52549c9492fe7c04.jpg'/> </a>\n <div><a href=\"/profile/raylee\" title=\"Specialist raylee\" class=\"rated-user user-cyan\">raylee</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/02/2014 11:07\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159679\" href=\"?#comment-159679\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"159679\" revisionCount=\"13\" revision=\"13\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">13</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"159679\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"135528\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159679\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In the problem D, said "The complexity is: <span class=\"tex-span\"><i>O</i>(<i>n</i><sup class=\"upper-index\">2</sup> <i>m</i>)</span> time." But n and m (2 ≤ n ≤ 500, 1 ≤ m ≤ 1000). Can you explain why this complexity wont TLE? thank you.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159679 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159679 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159679\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159685\" commentParentId=\"159679\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/gridnevvvit\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/31163/avatar/db500a30a0b0a6f1.jpg'/> </a>\n <div><a href=\"/profile/gridnevvvit\" title=\"Candidate Master gridnevvvit\" class=\"rated-user user-violet\">gridnevvvit</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/02/2014 11:55\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159685\" href=\"?#comment-159685\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159679\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159685\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"31163\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159685\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Yes. First, let's calculate number of operations: it is about <span class=\"tex-span\">2 * 10<sup class=\"upper-index\">8</sup></span>. It is not so much. If you have good implementation of Kuhn, it would pass. Also, I know, that number of operation is much lower than <span class=\"tex-span\">2 * 10<sup class=\"upper-index\">8</sup></span>.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159685 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159685 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159685\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159689\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/1nikhil9\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/60595/avatar/64f85d0070290be7.jpg'/> </a>\n <div><a href=\"/profile/1nikhil9\" title=\"Candidate Master 1nikhil9\" class=\"rated-user user-violet\">1nikhil9</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/02/2014 14:07\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159689\" href=\"?#comment-159689\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159689\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"60595\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159689\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Test case 4 for Problem D says N = 153, M = 392. But there are only 391 edges in the input file.</p><p><a href=\"//codeforces.com/contest/387/submission/5868021\">http://codeforces.com/contest/387/submission/5868021</a></p><p>Am I misunderstanding something? Thanks.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159689 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159689 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159689\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159694\" commentParentId=\"159689\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/gridnevvvit\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/31163/avatar/db500a30a0b0a6f1.jpg'/> </a>\n <div><a href=\"/profile/gridnevvvit\" title=\"Candidate Master gridnevvvit\" class=\"rated-user user-violet\">gridnevvvit</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/02/2014 15:06\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159694\" href=\"?#comment-159694\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159689\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159694\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"31163\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159694\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Testcase is valid.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159694 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159694 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159694\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"160860\" commentParentId=\"159694\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/khrak\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/128936/avatar/6d9b38f723c23a83.jpg'/> </a>\n <div><a href=\"/profile/khrak\" title=\"Expert khrak\" class=\"rated-user user-blue\">khrak</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/07/2014 20:07\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-160860\" href=\"?#comment-160860\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159694\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"160860\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"128936\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-160860\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>What does n variable mean in C problem tutorial? </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-160860 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-160860 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-160860\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"160876\" commentParentId=\"160860\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/gridnevvvit\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/31163/avatar/db500a30a0b0a6f1.jpg'/> </a>\n <div><a href=\"/profile/gridnevvvit\" title=\"Candidate Master gridnevvvit\" class=\"rated-user user-violet\">gridnevvvit</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/08/2014 00:57\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-160876\" href=\"?#comment-160876\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-160860\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"160876\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"31163\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-160876\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>n is the length of the number from the input.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-160876 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-160876 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-160876\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"160894\" commentParentId=\"160876\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/khrak\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/128936/avatar/6d9b38f723c23a83.jpg'/> </a>\n <div><a href=\"/profile/khrak\" title=\"Expert khrak\" class=\"rated-user user-blue\">khrak</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/08/2014 11:15\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-160894\" href=\"?#comment-160894\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-160876\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"160894\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"128936\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-160894\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>So, for 800101 we have a1 = 800, a2 = 10, a3 = 1, and n = 6. what value has i for this example, 1 or -1? </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-160894 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-160894 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-160894\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"160913\" commentParentId=\"160894\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/gridnevvvit\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/31163/avatar/db500a30a0b0a6f1.jpg'/> </a>\n <div><a href=\"/profile/gridnevvvit\" title=\"Candidate Master gridnevvvit\" class=\"rated-user user-violet\">gridnevvvit</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/08/2014 14:34\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-160913\" href=\"?#comment-160913\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-160894\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"160913\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"31163\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-160913\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>i equals to -1. I understood, that there is an small mistake: answer is <span class=\"tex-span\"><i>k</i> - <i>i</i> + 1</span></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-160913 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-160913 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-160913\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"160924\" commentParentId=\"160913\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/khrak\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/128936/avatar/6d9b38f723c23a83.jpg'/> </a>\n <div><a href=\"/profile/khrak\" title=\"Expert khrak\" class=\"rated-user user-blue\">khrak</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/08/2014 16:02\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-160924\" href=\"?#comment-160924\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-160913\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"160924\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"128936\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-160924\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Sorry for so many questions, but I can't still understand how we count answer answer for 800101. here k equals 3, i equals -1 (as you said), then answer should be k — i + 1 = 3 — (-1) + 1 = 5 when answer here is 3.. What I didn't understand correctly? </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-160924 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-160924 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-160924\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"160928\" commentParentId=\"160924\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/gridnevvvit\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/31163/avatar/db500a30a0b0a6f1.jpg'/> </a>\n <div><a href=\"/profile/gridnevvvit\" title=\"Candidate Master gridnevvvit\" class=\"rated-user user-violet\">gridnevvvit</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/08/2014 17:23\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-160928\" href=\"?#comment-160928\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-160924\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"160928\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"31163\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-160928\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Oh, it's my mistake. If there is no such index, index i should be equals to 1, yes.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-160928 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-160928 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-160928\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"160929\" commentParentId=\"160928\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/khrak\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/128936/avatar/6d9b38f723c23a83.jpg'/> </a>\n <div><a href=\"/profile/khrak\" title=\"Expert khrak\" class=\"rated-user user-blue\">khrak</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/08/2014 17:27\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-160929\" href=\"?#comment-160929\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-160928\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"160929\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"128936\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-160929\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Okey. Then I understand and I'll think about proof. Thank you! :) </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-160929 en true\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-160929 en true\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-160929\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"161379\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/rohitjv\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/107177/avatar/3326d08f28613bd4.jpg'/> </a>\n <div><a href=\"/profile/rohitjv\" title=\"Expert rohitjv\" class=\"rated-user user-blue\">rohitjv</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/12/2014 21:33\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-161379\" href=\"?#comment-161379\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"161379\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"107177\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-161379\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In problem C, the definition of the array <em>need[i]</em> in the description does not match with the code provided. The actual definition of <em>need[i]</em> should be : need[i] — equals to <strong>0</strong> if we should remove number i from permutation p, and <strong>1</strong> if we shouldn't remove i from permutation p. Please correct me if I am wrong.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-161379 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-161379 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-161379\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"161380\" commentParentId=\"161379\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/gridnevvvit\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/31163/avatar/db500a30a0b0a6f1.jpg'/> </a>\n <div><a href=\"/profile/gridnevvvit\" title=\"Candidate Master gridnevvvit\" class=\"rated-user user-violet\">gridnevvvit</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/12/2014 21:56\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-161380\" href=\"?#comment-161380\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-161379\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"161380\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"31163\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-161380\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Yes, description does not match with the code provided. There are only ideas in editorial, so there are can be differences. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-161380 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-161380 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-161380\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"161811\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Nakochi\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/101746/avatar/ccfafe3f7587f95d.jpg'/> </a>\n <div><a href=\"/profile/Nakochi\" title=\"Expert Nakochi\" class=\"rated-user user-blue\">Nakochi</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/17/2014 18:23\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-161811\" href=\"?#comment-161811\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"161811\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"101746\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-161811\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Problem C is really a challenge for me!!! Orz!!!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-161811 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-161811 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-161811\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"161820\" commentParentId=\"161811\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Nodir.Daminov\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/71439/avatar/d6d2016f6dfe5ecd.jpg'/> </a>\n <div><a href=\"/profile/Nodir.Daminov\" title=\"Candidate Master Nodir.Daminov\" class=\"rated-user user-violet\">Nodir.Daminov</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/17/2014 19:19\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-161820\" href=\"?#comment-161820\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-161811\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"161820\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"71439\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-161820\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Who cares ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-161820 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-161820 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-161820\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"161902\" commentParentId=\"161820\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Nakochi\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/101746/avatar/ccfafe3f7587f95d.jpg'/> </a>\n <div><a href=\"/profile/Nakochi\" title=\"Expert Nakochi\" class=\"rated-user user-blue\">Nakochi</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/18/2014 18:14\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-161902\" href=\"?#comment-161902\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-161820\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"161902\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"101746\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-161902\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Sorry, I misunderstood the problem. Now it's much easier. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-161902 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-161902 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-161902\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"161903\" commentParentId=\"161902\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Nodir.Daminov\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/71439/avatar/d6d2016f6dfe5ecd.jpg'/> </a>\n <div><a href=\"/profile/Nodir.Daminov\" title=\"Candidate Master Nodir.Daminov\" class=\"rated-user user-violet\">Nodir.Daminov</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/18/2014 18:25\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-161903\" href=\"?#comment-161903\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-161902\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"161903\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"71439\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-161903\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Who cares ???</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-161903 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-161903 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-161903\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"161904\" commentParentId=\"161903\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Nakochi\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/101746/avatar/ccfafe3f7587f95d.jpg'/> </a>\n <div><a href=\"/profile/Nakochi\" title=\"Expert Nakochi\" class=\"rated-user user-blue\">Nakochi</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/18/2014 18:54\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-161904\" href=\"?#comment-161904\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-161903\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"161904\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"101746\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-161904\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Seems you care. :D</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-161904 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-161904 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-161904\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n <br/>\r\n\r\n<div id=\"editBox-10654\" style=\"width:50em;display:none;\">\r\n <div class=\"previewBody\" style=\"border: 1px solid #d4d4d4; margin-bottom: 0.5em; padding: 0.25em; display:none;\"> </div>\r\n <div style=\"width: 1px\"> </div>\r\n <div class=\"commentLocale\" style=\"position: relative; top: 0.5em;left:4px;display: none;\">\r\n <input type=\"radio\" name=\"locale\" value=\"en\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In English</span>\r\n <input style=\"margin-left:1em\" type=\"radio\" name=\"locale\" value=\"ru\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In Russian</span>\r\n </div>\r\n <textarea data-drafts-id=\"CommentReplyFrame\" class=\"wysiwyg\" name=\"editContent\" rows=\"20\" style=\"width:99%;\"></textarea>\r\n <div class=\"error error__content\"></div>\r\n <div style=\"text-align:center;\">\r\n <input type=\"button\" name=\"preview\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Preview\"/>\r\n <input type=\"button\" name=\"save\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Save\"/>\r\n </div>\r\n</div>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n\r\nvar firstPreview10654 = true;\r\nvar lastPreviewContent10654 = '';\r\n\r\nif (!window.moveCommentRevision) {\r\n moveCommentRevision = function(e, dir) {\r\n var p = e.parent();\r\n var revisionCount = parseInt(p.attr(\"revisionCount\"));\r\n var revision = parseInt(p.attr(\"revision\"));\r\n var next = revision + dir;\r\n var commentId = p.attr(\"commentId\");\r\n if (next >= 1 && next <= revisionCount) {\r\n $.post(\r\n \"/data/comment-data\",\r\n {action: \"revision\", commentId: commentId, revision: next},\r\n function(json) {\r\n if (json.success == \"true\") {\r\n var parentDiv = e;\r\n\r\n while (parentDiv !== null && (parentDiv[0].nodeName.toLowerCase() !== \"td\" || !parentDiv.hasClass(\"right\"))) {\r\n parentDiv = parentDiv.parent();\r\n }\r\n\r\n if (parentDiv === null) {\r\n return;\r\n }\r\n\r\n parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\").html(json.content);\r\n Codeforces.setupSpoilers(parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\"));\r\n p.attr(\"revision\", next);\r\n p.find(\"span.revision\").text(next);\r\n if (next == 1) {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"visible\");\r\n }\r\n if (next == revisionCount) {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"visible\");\r\n }\r\n\r\n window.updateTypography();\r\n MathJax.Hub.Typeset();\r\n } else {\r\n alert(e.error);\r\n }\r\n },\r\n \"json\"\r\n );\r\n }\r\n };\r\n}\r\n\r\n$(\"div[commentableId=10654] a.leftRevision\").click(function () {\r\n window.moveCommentRevision($(this), -1);\r\n return false;\r\n});\r\n\r\n$(\"div[commentableId=10654] a.rightRevision\").click(function () {\r\n window.moveCommentRevision($(this), +1);\r\n return false;\r\n});\r\n\r\n\r\n\r\n });\n </script>\n\r\n\r\n <script src=\"//codeforces.org/s/81027/js/swfobject-2.2.min.js\" type=\"text/javascript\"></script>\n <script src=\"//codeforces.org/s/81027/js/ftaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n if (window.evercookie) {\n var ec = new evercookie({\n history: false,\n silverlight: false,\n baseurl: '',\n asseturi: '/assets',\n phpuri: '/2fdcd78',\n pngPath: '/eps',\n etagPath: '/ees',\n cachePath: '/ecs'\n });\n\n var randomNumber = function () {\n return Math.random().toString(36).substr(2);\n };\n\n var randomToken = function () {\n return (randomNumber() + randomNumber()).substring(0, 18);\n };\n\n window._ftaa = \"\";\n\n ec.get(\"70a7c28f3de\", function (value) {\n window._ftaa = value;\n if (!window._ftaa) {\n window._ftaa = randomToken();\n ec.set(\"70a7c28f3de\", window._ftaa);\n }\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n } else {\n window._ftaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\n <script src=\"//codeforces.org/s/81027/js/bfaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n var fpCallback = function() {\n Fingerprint2.get({}, function(components) {\n window._bfaa = Fingerprint2.x64hash128(components.map(function (pair) { return pair.value }).join(), 31);\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n };\n if (typeof Fingerprint2 !== 'undefined') {\n if (window.requestIdleCallback) {\n requestIdleCallback(fpCallback)\n } else {\n setTimeout(fpCallback, 500)\n }\n } else {\n window._bfaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"a.new-root-comment\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n\r\n $(\".comment-table .reply a\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".vote-for-comment\").mouseover(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").mouseout(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").click(function () {\r\n var vote = $(this);\r\n var commentId = $(this).parent().attr(\"commentid\");\r\n var commentRating = $(this).parent().attr(\"data-commentRating\");\r\n var direction = $(this).attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n $.post(\"/data/comment/vote\", {commentId: commentId, _tta: Codeforces.tta(), vote: direction, commentRating: commentRating}, function(data) {\r\n if (direction != 0 && !ownComment && data[\"success\"] == \"true\") {\r\n vote.parent().find(\".vote-for-comment\").attr(\"voteDirection\", 0);\r\n if (direction == 1)\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n else {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.closest(\".CommentVoteFrame\").find(\".ComplaintFrame\").css(\"display\", \"inline-block\");\r\n }\r\n vote.find(\"img\").attr(\"popacity\", \"1.0\");\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n vote.parent().find(\".commentRating\").html(data[\"commentRating\"]);\r\n }\r\n Codeforces.showMessage(data[\"message\"]);\r\n }, \"json\");\r\n return false;\r\n });\r\n\r\n $(\".negative-comment-vote\").closest(\".comment-table\").addClass(\"comment-bad\");\r\n\r\n $(\".troll-comment-vote\").closest(\".comment\").css(\"display\", \"none\");\r\n\r\n $(\".too-negative-comment-vote\").closest(\".comment-table\").each(function () {\r\n var e = $(this);\r\n e.addClass(\"comment-too-bad\");\r\n var commentId = e.attr(\"commentId\");\r\n $(\"<div class='bad-comment-replacement ttypography'>The comment is hidden because of too negative feedback, click <a href=# class=show-bad-comment-link>here</a> to view it</div>\").appendTo(\r\n e.find(\".right\")\r\n );\r\n e.find(\".comment-content\").hide();\r\n e.find(\".show-bad-comment-link\").click(function () {\r\n e.find(\".comment-content\").show();\r\n e.find(\".bad-comment-replacement\").hide();\r\n return false;\r\n });\r\n });\r\n });\n </script>\n </div>\r\n\r\n <style type=\"text/css\">\r\n .new-comments-box {\r\n padding: 0.5em;\r\n width: 22px;\r\n font-size: 1.3rem;\r\n font-weight: bold !important;\r\n\r\n position: fixed;\r\n top: 40%;\r\n right: 0;\r\n opacity: 0.2;\r\n color: white;\r\n text-align: center;\r\n\r\n border: 1px solid #222;\r\n background-color: #888 !important;\r\n border-radius: 3px;\r\n -moz-border-radius: 3px;\r\n -webkit-border-radius: 3px;\r\n }\r\n\r\n .new-comments-box:hover {\r\n opacity: 1;\r\n }\r\n\r\n .new-comments-box .dir:hover {\r\n background: #3B5998 !important;\r\n cursor: pointer;\r\n }\r\n </style>\r\n\r\n <div class=\"new-comments-box\" data-position=\"outside\" data-index=\"-1\" style=\"display: none;\">\r\n <div class=\"up dir\" title=\"Ctrl+Up\">↑<hr/>\r\n </div>\r\n <div class=\"info\" title=\"New comments\"></div>\r\n <div class=\"down dir\" title=\"Ctrl+Down\">\r\n <hr/>↓\r\n </div>\r\n </div>\r\n\r\n <script>\r\n $(\".show-archived-checkbox\").change(function () {\r\n const checked = $(this).is(\":checked\");\r\n $.post(\"/data/comment-data\", {action: \"setShowArchived\", checked}, function (json) {\r\n if (json[\"success\"] !== \"true\") {\r\n alert(json[\"error\"]);\r\n } else {\r\n if (checked) {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are now displayed\")\r\n } else {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are no longer displayed\")\r\n }\r\n }\r\n });\r\n return false;\r\n });\r\n\r\n function gotoComment(direction) {\r\n var box = $(\".new-comments-box\");\r\n var index = parseInt(box.attr(\"data-index\"));\r\n if (index == -1)\r\n index = 0;\r\n else\r\n index = Math.max(0, Math.min(parseInt(box.find(\".info\").text()) - 1, index + direction));\r\n box.attr(\"data-index\", index);\r\n var comment = $($(\".comment .highlight-blue[commentId]\").get(index));\r\n $('html, body').animate({\r\n 'scrollTop': Math.max(0, comment.offset().top - ($(window).height() - comment.height()) / 2)\r\n });\r\n return false;\r\n }\r\n\r\n $(\".new-comments-box .down\").click(function () {\r\n return gotoComment(1);\r\n });\r\n\r\n $(\".new-comments-box .up\").click(function () {\r\n return gotoComment(-1);\r\n });\r\n\r\n $(document).keydown(function (e) {\r\n var code = (e.keyCode ? e.keyCode : e.which);\r\n if (e.ctrlKey) {\r\n if (code == 38 || code == 40) {\r\n gotoComment(code - 39);\r\n }\r\n }\r\n });\r\n\r\n var newCommentCount = $(\".comment .highlight-blue[commentId]\").length;\r\n if (newCommentCount > 0) {\r\n $(\".new-comments-box .info\").text(newCommentCount);\r\n $(\".new-comments-box\").show();\r\n }\r\n\r\n $('table.comment-table').mouseenter(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").addClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n\r\n $('table.comment-table').mouseleave(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").removeClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n </script>\r\n\r\n\r\n\r\n <script>\r\n function adjustTopicComplainFrames() {\r\n let topicIds = [];\r\n\r\n $(\".has-topic-id\").each(function () {\r\n const $this = $(this);\r\n const topicId = $this.attr(\"topicId\");\r\n if (topicId) {\r\n topicIds.push(topicId);\r\n }\r\n });\r\n\r\n $.post(\"/data/topics\", {\r\n action: \"findComplainableTopicIds\",\r\n topicIds: topicIds.join(\",\")\r\n }, function (json) {\r\n if (json[\"success\"] === \"true\") {\r\n for (const topicId of json[\"complainableTopicIds\"].split(\",\")) {\r\n $(\".has-topic-id[topicId=\" + topicId + \"]\").each(function () {\r\n $(this).find(\".meta .ComplaintFrame\").css(\"display\", \"inline-block\");\r\n });\r\n }\r\n }\r\n }, \"json\");\r\n }\r\n\r\n $(function () {\r\n adjustTopicComplainFrames();\r\n })\r\n </script>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-10638\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 10638, _tta: Codeforces.tta(), topicRevisionId: 37197, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-10638\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 10638, _tta: Codeforces.tta(), topicRevisionId: 37197, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n </div>\r\n </div>\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 22:13:05</span> (h1).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/81027/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/81027/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/81027/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/81027/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-81027.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'812875999be52de2',t:'MTY5NjcwNTk4NS43NTIwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"}}},{"rowIdx":1954,"cells":{"problem_id":{"kind":"string","value":"387B"},"contest":{"kind":"string","value":"387"},"problem":{"kind":"string","value":"B"},"lang":{"kind":"string","value":"en"},"problem_title":{"kind":"string","value":"B. George and Round"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">B. George and Round</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>George decided to prepare a Codesecrof round, so he has prepared <span class=\"tex-span\"><i>m</i></span> problems for the round. Let's number the problems with integers <span class=\"tex-span\">1</span> through <span class=\"tex-span\"><i>m</i></span>. George estimates the <span class=\"tex-span\"><i>i</i></span>-th problem's complexity by integer <span class=\"tex-span\"><i>b</i><sub class=\"lower-index\"><i>i</i></sub></span>.</p><p>To make the round <span class=\"tex-font-style-it\">good</span>, he needs to put at least <span class=\"tex-span\"><i>n</i></span> problems there. Besides, he needs to have at least one problem with complexity exactly <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub></span>, at least one with complexity exactly <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">2</sub></span>, ..., and at least one with complexity exactly <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>n</i></sub></span>. Of course, the round can also have problems with other complexities.</p><p>George has a poor imagination. It's easier for him to make some already prepared problem simpler than to come up with a new one and prepare it. George is magnificent at simplifying problems. He can simplify any already prepared problem with complexity <span class=\"tex-span\"><i>c</i></span> to any positive integer complexity <span class=\"tex-span\"><i>d</i></span> (<span class=\"tex-span\"><i>c</i> ≥ <i>d</i></span>), by changing limits on the input data.</p><p>However, nothing is so simple. George understood that even if he simplifies some problems, he can run out of problems for a <span class=\"tex-font-style-it\">good</span> round. That's why he decided to find out the minimum number of problems he needs to come up with in addition to the <span class=\"tex-span\"><i>m</i></span> he's prepared in order to make a good round. Note that George can come up with a new problem of any complexity.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains two integers <span class=\"tex-span\"><i>n</i></span> and <span class=\"tex-span\"><i>m</i></span> (<span class=\"tex-span\">1 ≤ <i>n</i>, <i>m</i> ≤ 3000</span>) — the minimal number of problems in a good round and the number of problems George's prepared. The second line contains space-separated integers <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub>, <i>a</i><sub class=\"lower-index\">2</sub>, ..., <i>a</i><sub class=\"lower-index\"><i>n</i></sub></span> (<span class=\"tex-span\">1 ≤ <i>a</i><sub class=\"lower-index\">1</sub> < <i>a</i><sub class=\"lower-index\">2</sub> < ... < <i>a</i><sub class=\"lower-index\"><i>n</i></sub> ≤ 10<sup class=\"upper-index\">6</sup></span>) — the requirements for the complexity of the problems in a good round. The third line contains space-separated integers <span class=\"tex-span\"><i>b</i><sub class=\"lower-index\">1</sub>, <i>b</i><sub class=\"lower-index\">2</sub>, ..., <i>b</i><sub class=\"lower-index\"><i>m</i></sub></span> (<span class=\"tex-span\">1 ≤ <i>b</i><sub class=\"lower-index\">1</sub> ≤ <i>b</i><sub class=\"lower-index\">2</sub>... ≤ <i>b</i><sub class=\"lower-index\"><i>m</i></sub> ≤ 10<sup class=\"upper-index\">6</sup></span>) — the complexities of the problems prepared by George. </p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print a single integer — the answer to the problem.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>3 5<br/>1 2 3<br/>1 2 2 3 3<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>0<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3 5<br/>1 2 3<br/>1 1 1 1 1<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>2<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3 1<br/>2 3 4<br/>1<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>3<br/></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>In the first sample the set of the prepared problems meets the requirements for a good round.</p><p>In the second sample, it is enough to come up with and prepare two problems with complexities <span class=\"tex-span\">2</span> and <span class=\"tex-span\">3</span> to get a good round.</p><p>In the third sample it is very easy to get a good round if come up with and prepare extra problems with complexities: <span class=\"tex-span\">2, 3, 4</span>. </p></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"34eeca9c40ad8e6c5736285b49958417\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - B - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"1d8414af0a90e113b8a49898336bf2bc6a1719bc\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - B - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/73366/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/73366/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/73366/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/73366/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/73366/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/73366/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/73366/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/73366/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/73366/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/73366/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/73366/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/73366/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/73366/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/73366/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/sidebar-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/a037fe51637846d9c7c725713cd840ea/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='34eeca9c40ad8e6c5736285b49958417'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/73366/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/73366/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fcontest%2F387%2Fproblem%2FB%3Flocale%3Den\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"current\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='34eeca9c40ad8e6c5736285b49958417'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:100%;\"><a style=\"color: black\" href=\"/contest/387\">Codeforces Round 227 (Div. 2)</a></th>\n </tr>\n <tr>\n <td class=\"left bottom\" colspan=\"1\"><span class=\"contest-state-phase\">Finished</span></td>\n </tr>\n </tbody>\n </table>\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Practice?\n <div class=\"top-links\">\n </div>\n </div>\n<div>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Want to solve the contest problems after the official contest ends? Just register for practice and you will be able to submit solutions.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"\" method=\"post\"><input type='hidden' name='csrf_token' value='34eeca9c40ad8e6c5736285b49958417'/>\r\n <input type=\"hidden\" name=\"action\" value=\"registerForPractice\"/>\r\n <input type=\"submit\" name=\"submit\" value=\"Register for practice\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div> \r\n</div>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox ContestVirtualFrame borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Virtual participation <i class=\"sidebar-caption-icon las la-angle-down\"></i>\r\n\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\" \"\r\n\r\n data-page-url=\"/data/sidebarFrames\"\r\n\r\n>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests.\n\nIf you've seen these problems, a virtual contest is not for you - solve these problems in the archive.\n\nIf you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.\n\nNever use someone else's code, read the tutorials or communicate with other person during a virtual contest.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"/contest/387/virtual\" method=\"get\">\r\n <input type=\"submit\" name=\"submit\" value=\"Start virtual contest\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div>\r\n</div>\r\n <script>\r\n $(function () {\r\n $(\".ContestVirtualFrame .sidebar-caption-icon\").click(function() {\r\n $(this).toggleClass(\"la-angle-down la-angle-right\");\r\n const $target = $(this).parent().next();\r\n $target.toggle();\r\n const dataPageUrl = $target.attr(\"data-page-url\");\r\n const collapsed = $(this).hasClass(\"la-angle-right\");\r\n const params = {\r\n action: \"setCollapsed\",\r\n sidebarFrameSimpleClassName: \"ContestVirtualFrame\",\r\n collapsed\r\n };\r\n $.each($target[0].attributes, function(i, a) {\r\n const name = a.name;\r\n if (name.startsWith(\"data-extra-key-\")) {\r\n const key = a.value;\r\n const keyIndex = parseInt(name.substring(\"data-extra-key-\".length));\r\n const value = $target.attr(\"data-extra-value-\" + keyIndex);\r\n params[key] = value;\r\n }\r\n });\r\n $.post(dataPageUrl, params, function (result) {\r\n if (result[\"success\"] !== \"true\") {\r\n Codeforces.showMessage(\"Failed to save collapsed state.\");\r\n }\r\n }, \"json\");\r\n return false;\r\n });\r\n })\r\n </script>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Problem tags\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Brute force\">\r\n brute force\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Greedy algorithms\">\r\n greedy\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Two pointers\">\r\n two pointers\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Difficulty\">\r\n *1200\r\n</span>\r\n </div>\n <div style=\"clear:both;text-align:right;font-size:1.1rem;\">\r\n <span title=\"Please login into the Codeforces\" class=\"notice\">No tag edit access</span>\r\n </div>\r\n</div>\r\n </div>\n\r\n<form id=\"addTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='34eeca9c40ad8e6c5736285b49958417'/>\r\n <input name=\"action\" type=\"hidden\" value=\"addTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"6207\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<form id=\"removeTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='34eeca9c40ad8e6c5736285b49958417'/>\r\n <input name=\"action\" type=\"hidden\" value=\"removeTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"6207\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<script type=\"text/javascript\">\r\n $(\".tag-box img\").click(function () {\r\n var tagName = $(this).attr(\"value\");\r\n Codeforces.confirm(\"Are you sure you want to remove this tag?\", function () {\r\n $(\"#removeTagForm input[name=tagName]\").val(tagName);\r\n $(\"#removeTagForm\").submit();\r\n }, function () {\r\n }, \"Yes\", \"No\");\r\n });\r\n\r\n $(\"#addTagLink\").click(function () {\r\n $(this).hide();\r\n $(\"#addTagLabel\").show();\r\n return false;\r\n });\r\n\r\n $(\"#addTagSelect\").change(function () {\r\n var tagName = $(this).val();\r\n if (tagName === \"\") {\r\n $(\"#addTagLabel\").hide();\r\n $(\"#addTagLink\").show();\r\n } else {\r\n $(\"#addTagForm input[name=tagName]\").val(tagName);\r\n $(\"#addTagForm\").submit();\r\n }\r\n });\r\n</script>\r\n\r\n<style type=\"text/css\">\r\n#new-resource-form tr td {\r\npadding-top: 0.5em;\r\n}\r\n#new-resource-form input:not([type=\"submit\"]) {\r\nfont-size: 0.8em;\r\n}\r\n#new-resource-form select {\r\nfont-size: 0.8em;\r\n}\r\n.new-resource-error {\r\nfont-size: 0.8em;\r\n}\r\n.resource-locale {\r\ncolor: #666;\r\nfont-family: Consolas, \"Andale Mono WT\", \"Andale Mono\", \"Lucida Console\", \"Lucida Sans Typewriter\", \"DejaVu Sans Mono\", \"Bitstream Vera Sans Mono\", \"Liberation Mono\", \"Nimbus Mono L\", Monaco, \"Courier New\", Courier, monospace;\r\n}\r\n</style>\r\n<div class=\"roundbox sidebox sidebar-menu borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Contest materials\n<div class=\"top-links\">\n</div>\n</div>\n<ul>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/10569\" title=\"Codeforces Round #227 (Div. 2)\" target=\"_blank\">Announcement</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"2176:2182\" resourceName=\"Announcement\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/10583\" title=\"Editorial Codeforces Round #227 (Div. 2)\" target=\"_blank\">Tutorial</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"2177:2183\" resourceName=\"Tutorial\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n</ul>\r\n</div></div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li class=\"current selectedLava\"><a\r\n href=\"/contest/387\">Problems</a></li>\r\n <li><a\r\n href=\"/contest/387/submit\">Submit Code</a></li>\r\n <li><a\r\n href=\"/contest/387/my\">My Submissions</a></li>\r\n <li><a\r\n href=\"/contest/387/status\">Status</a></li>\r\n <li><a\r\n href=\"/contest/387/hacks\">Hacks</a></li>\r\n <li><a\r\n href=\"/contest/387/room/1\">Room</a></li>\r\n <li><a\r\n href=\"/contest/387/standings\">Standings</a></li>\r\n <li><a\r\n href=\"/contest/387/customtest\">Custom Invocation</a></li>\r\n</ul>\r\n</div>\n\r\n <style>\r\n #facebox .content:has(.diff-popup) {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n }\r\n\r\n .testCaseMarker {\r\n position: absolute;\r\n font-weight: bold;\r\n font-size: 1rem;\r\n }\r\n\r\n .diff-popup {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n display: none;\r\n overflow: auto;\r\n }\r\n\r\n .input-output-copier {\r\n font-size: 1.2rem;\r\n float: right;\r\n color: #888 !important;\r\n cursor: pointer;\r\n border: 1px solid rgb(185, 185, 185);\r\n padding: 3px;\r\n margin: 1px;\r\n line-height: 1.1rem;\r\n text-transform: none;\r\n }\r\n\r\n .input-output-copier:hover {\r\n background-color: #def;\r\n }\r\n\r\n .test-explanation textarea {\r\n width: 100%;\r\n height: 1.5em;\r\n }\r\n\r\n .pending-submission-message {\r\n color: darkorange !important;\r\n }\r\n </style>\r\n <script>\r\n const OPENING_SPACE = String.fromCharCode(1001);\r\n const CLOSING_SPACE = String.fromCharCode(1002);\r\n\r\n const nodeToText = function (node, pre) {\r\n let result = [];\r\n\r\n if (node.tagName === \"SCRIPT\" || node.tagName === \"math\"\r\n || (node.classList && node.classList.contains(\"input-output-copier\")))\r\n return [];\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(OPENING_SPACE);\r\n }\r\n\r\n if (node.nodeType === Node.TEXT_NODE) {\r\n let s = node.textContent;\r\n if (!pre) {\r\n s = s.replace(/\\s+/g, \" \");\r\n }\r\n if (s.length > 0) {\r\n result.push(s);\r\n }\r\n }\r\n\r\n if (pre && node.tagName === \"BR\") {\r\n result.push(\"\\n\");\r\n }\r\n\r\n node.childNodes.forEach(function (child) {\r\n result.push(nodeToText(child, node.tagName === \"PRE\").join(\"\"));\r\n });\r\n\r\n if (node.tagName === \"DIV\"\r\n || node.tagName === \"P\"\r\n || node.tagName === \"PRE\"\r\n || node.tagName === \"UL\"\r\n || node.tagName === \"LI\"\r\n ) {\r\n result.push(\"\\n\");\r\n }\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(CLOSING_SPACE);\r\n }\r\n\r\n return result;\r\n }\r\n\r\n const isSpecial = function (c) {\r\n return c === ',' || c === '.' || c === ';' || c === ')' || c === ' ';\r\n }\r\n\r\n const convertStatementToText = function(statmentNode) {\r\n const text = nodeToText(statmentNode, false).join(\"\").replace(/ +/g, \" \").replace(/\\n\\n+/g, \"\\n\\n\");\r\n let result = [];\r\n for (let i = 0; i < text.length; i++) {\r\n const c = text.charAt(i);\r\n if (c === OPENING_SPACE) {\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"B\" data-uuid=\"ps_735f54416ab68439c20ae27d4dbc1be65690ee44\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">B. George and Round</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>George decided to prepare a Codesecrof round, so he has prepared <span class=\"tex-span\"><i>m</i></span> problems for the round. Let's number the problems with integers <span class=\"tex-span\">1</span> through <span class=\"tex-span\"><i>m</i></span>. George estimates the <span class=\"tex-span\"><i>i</i></span>-th problem's complexity by integer <span class=\"tex-span\"><i>b</i><sub class=\"lower-index\"><i>i</i></sub></span>.</p><p>To make the round <span class=\"tex-font-style-it\">good</span>, he needs to put at least <span class=\"tex-span\"><i>n</i></span> problems there. Besides, he needs to have at least one problem with complexity exactly <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub></span>, at least one with complexity exactly <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">2</sub></span>, ..., and at least one with complexity exactly <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>n</i></sub></span>. Of course, the round can also have problems with other complexities.</p><p>George has a poor imagination. It's easier for him to make some already prepared problem simpler than to come up with a new one and prepare it. George is magnificent at simplifying problems. He can simplify any already prepared problem with complexity <span class=\"tex-span\"><i>c</i></span> to any positive integer complexity <span class=\"tex-span\"><i>d</i></span> (<span class=\"tex-span\"><i>c</i> ≥ <i>d</i></span>), by changing limits on the input data.</p><p>However, nothing is so simple. George understood that even if he simplifies some problems, he can run out of problems for a <span class=\"tex-font-style-it\">good</span> round. That's why he decided to find out the minimum number of problems he needs to come up with in addition to the <span class=\"tex-span\"><i>m</i></span> he's prepared in order to make a good round. Note that George can come up with a new problem of any complexity.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains two integers <span class=\"tex-span\"><i>n</i></span> and <span class=\"tex-span\"><i>m</i></span> (<span class=\"tex-span\">1 ≤ <i>n</i>, <i>m</i> ≤ 3000</span>) — the minimal number of problems in a good round and the number of problems George's prepared. The second line contains space-separated integers <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub>, <i>a</i><sub class=\"lower-index\">2</sub>, ..., <i>a</i><sub class=\"lower-index\"><i>n</i></sub></span> (<span class=\"tex-span\">1 ≤ <i>a</i><sub class=\"lower-index\">1</sub> < <i>a</i><sub class=\"lower-index\">2</sub> < ... < <i>a</i><sub class=\"lower-index\"><i>n</i></sub> ≤ 10<sup class=\"upper-index\">6</sup></span>) — the requirements for the complexity of the problems in a good round. The third line contains space-separated integers <span class=\"tex-span\"><i>b</i><sub class=\"lower-index\">1</sub>, <i>b</i><sub class=\"lower-index\">2</sub>, ..., <i>b</i><sub class=\"lower-index\"><i>m</i></sub></span> (<span class=\"tex-span\">1 ≤ <i>b</i><sub class=\"lower-index\">1</sub> ≤ <i>b</i><sub class=\"lower-index\">2</sub>... ≤ <i>b</i><sub class=\"lower-index\"><i>m</i></sub> ≤ 10<sup class=\"upper-index\">6</sup></span>) — the complexities of the problems prepared by George. </p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print a single integer — the answer to the problem.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>3 5<br />1 2 3<br />1 2 2 3 3<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>0<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3 5<br />1 2 3<br />1 1 1 1 1<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>2<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3 1<br />2 3 4<br />1<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>3<br /></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>In the first sample the set of the prepared problems meets the requirements for a good round.</p><p>In the second sample, it is enough to come up with and prepare two problems with complexities <span class=\"tex-span\">2</span> and <span class=\"tex-span\">3</span> to get a good round.</p><p>In the third sample it is very easy to get a good round if come up with and prepare extra problems with complexities: <span class=\"tex-span\">2, 3, 4</span>. </p></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=B]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== statementText) {\r\n $problem.find(\".diff-notifier\").show();\r\n\r\n $problem.find(\".diff-notifier-close\").click(function() {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n $problem.find(\".diff-notifier\").hide();\r\n });\r\n\r\n $problem.find(\"a.view-changes\").click(function() {\r\n $.post(\"/data/diff\", {action: \"getDiff\", a: previousStatementText, b: statementText}, function (result) {\r\n if (result[\"success\"] === \"true\") {\r\n Codeforces.facebox(\".diff-popup\", \"//codeforces.org/s/73366\");\r\n $(\"#facebox .diff-popup\").html(result[\"diff\"]);\r\n }\r\n }, \"json\");\r\n });\r\n }\r\n } else {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n }\r\n });\r\n });\r\n </script>\r\n\r\n\r\n<script type=\"text/javascript\">\r\n $(document).ready(function () {\r\n window.changedTests = new Set();\r\n\r\n function endsWith(string, suffix) {\r\n return string.indexOf(suffix, string.length - suffix.length) !== -1;\r\n }\r\n\r\n const inputFileDiv = $(\"div.input-file\");\r\n const inputFile = inputFileDiv.text();\r\n const outputFileDiv = $(\"div.output-file\");\r\n const outputFile = outputFileDiv.text();\r\n\r\n\r\n if (!endsWith(inputFile, \"standard input\")\r\n && !endsWith(inputFile, \"standard input\")) {\r\n inputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n if (!endsWith(outputFile, \"standard output\")\r\n && !endsWith(outputFile, \"standard output\")) {\r\n outputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n const titleDiv = $(\"div.header div.title\");\r\n\r\n\r\n\r\n String.prototype.replaceAll = function (search, replace) {\r\n return this.split(search).join(replace);\r\n };\r\n\r\n $(\".sample-test .title\").each(function () {\r\n const preId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n const cpyId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n\r\n $(this).parent().find(\"pre\").attr(\"id\", preId);\r\n const $copy = $(\"<div title='Copy' data-clipboard-target='#\" + preId + \"' id='\" + cpyId + \"' class='input-output-copier'>Copy</div>\");\r\n $(this).append($copy);\r\n\r\n const clipboard = new Clipboard('#' + cpyId, {\r\n text: function (trigger) {\r\n const pre = document.querySelector('#' + preId);\r\n const lines = pre.querySelectorAll(\".test-example-line\");\r\n return Codeforces.filterClipboardText(pre.innerText, lines.length);\r\n }\r\n });\r\n\r\n const isInput = $(this).parent().hasClass(\"input\");\r\n\r\n clipboard.on('success', function (e) {\r\n if (isInput) {\r\n Codeforces.showMessage(\"The example input has been copied into the clipboard\");\r\n } else {\r\n Codeforces.showMessage(\"The example output has been copied into the clipboard\");\r\n }\r\n e.clearSelection();\r\n });\r\n });\r\n\r\n $(\".test-form-item input\").change(function () {\r\n addPendingSubmissionMessage($($(this).closest(\"form\")), \"You changed the answer, do not forget to submit it if you want to save the changes\");\r\n const index = $(this).closest(\".problemindexholder\").attr(\"problemindex\");\r\n let test = \"\";\r\n $(this).closest(\"form input\").each(function () {\r\n const test_ = $(this).attr(\"name\");\r\n if (test_ && test_.substring(0, 4) === \"test\") {\r\n test = test_;\r\n }\r\n });\r\n if (index.length > 0 && test.length > 0) {\r\n const indexTest = index + \"::\" + test;\r\n window.changedTests.add(indexTest);\r\n }\r\n });\r\n\r\n $(window).on('beforeunload', function () {\r\n if (window.changedTests.size > 0) {\r\n return 'Dialog text here';\r\n }\r\n });\r\n\r\n autosize($('.test-explanation textarea'));\r\n\r\n $(\".test-example-line\").hover(function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n let top = 1E20;\r\n let left = 1E20;\r\n let problem = $(this).closest(\".problemindexholder\");\r\n $(this).closest(\".input\").find(\".\" + clazz).css(\"background-color\", \"#FFFDE7\").each(function() {\r\n top = Math.min(top, $(this).offset().top);\r\n left = Math.min(left, $(this).offset().left);\r\n });\r\n let testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n if (testCaseMarker.length === 0) {\r\n const html = \"<div class=\\\"testCaseMarker testCaseMarker_\" + end + \" notice\\\"></div>\";\r\n problem.append($(html));\r\n testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n }\r\n if (testCaseMarker) {\r\n testCaseMarker.show()\r\n .offset({top, left: left - 20})\r\n .text(end);\r\n }\r\n }\r\n }\r\n });\r\n }, function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n $(\".\" + clazz).css(\"background-color\", \"\");\r\n $(this).closest(\".problemindexholder\").find(\".testCaseMarker_\" + end).hide();\r\n }\r\n }\r\n });\r\n });\r\n\r\n });\r\n</script>\r\n\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 05:38:24</span> (j3).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/73366/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/73366/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/73366/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/73366/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-73366.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'8122c4881c799d34',t:'MTY5NjY0NjMwNC4wODgwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"},"long_tags":{"kind":"string","value":"[\"Brute force\", \"Greedy algorithms\", \"Two pointers\"]"},"short_tags":{"kind":"string","value":"[\"brute force\", \"greedy\", \"two pointers\", \"*1200\"]"},"tutorial_link":{"kind":"string","value":"https://codeforces.com/blog/entry/10583"},"tutorial_page":{"kind":"string","value":"\r\n\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"36a5cb4572cb122db333ec3b9f88364a\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"h1\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Editorial Codeforces Round #227 (Div. 2) - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n \n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Editorial Codeforces Round #227 (Div. 2) - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/81027/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/81027/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/81027/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/81027/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/81027/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/81027/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/81027/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/81027/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/81027/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/81027/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/81027/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/81027/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/81027/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/81027/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/573cedc6b04c15481941f418269f4057/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='36a5cb4572cb122db333ec3b9f88364a'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/81027/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fblog%2Fentry%2F10583\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='36a5cb4572cb122db333ec3b9f88364a'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Pay attention\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n <div style=\"text-align:center;border-bottom: 1px solid rgb(185, 185, 185);margin:0 -0.5em 0.5em -0.5em;padding: 0 1em 0.5em 1em;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 1, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:51:56</span><br/><a href=\"/contestRegistration/1876\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n <div style=\"text-align:center;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 2, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:51:56</span><br/><a href=\"/contestRegistration/1877\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n\r\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div>\r\n\r\n\n <div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\n\r\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='36a5cb4572cb122db333ec3b9f88364a'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n </label>\r\n </div>\r\n <div style=\"padding: 0 1em 1em 1em;text-align:right;\">\r\n <input style=\"height:1.65em;padding:0 0.75em;\" type=\"submit\" value=\"Find\"/>\r\n </div>\r\n </form>\r\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".handleBox\").autocomplete(\"/data/handles\", {\r\n delay: 200,\r\n width: 200,\r\n selectFirst: false,\r\n matchContains: true,\r\n minChars: 3\r\n });\r\n $(\".handleForm\").attr(\"autocomplete\", \"off\").submit(function () {\r\n var link = \"/profile/userHandle\".replace(\r\n \"userHandle\", $(this).find(\".handleBox\").val()\r\n );\r\n window.location = link;\r\n return false;\r\n });\r\n });\n </script>\n\r\n\r\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Recent actions\n <div class=\"top-links\">\n </div>\n </div>\n <div class=\"recent-actions\">\r\n <ul>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/121073\">Meta Hacker Cup 2023 Round 1</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/.Danet\" title=\"Expert .Danet\" class=\"rated-user user-blue\">.Danet</a> →\r\n <a href=\"/blog/entry/121172\">[TLE on pretest1]</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\" class=\"rated-user user-red\">Pyqe</a> →\r\n <a href=\"/blog/entry/121025\">Codeforces Round #902 (Div. 1, Div. 2, based on COMPFEST 15 — Final Round)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pranshu_Pandya\" title=\"Specialist Pranshu_Pandya\" class=\"rated-user user-cyan\">Pranshu_Pandya</a> →\r\n <a href=\"/blog/entry/121171\">An Interesting Tree Problem</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/sszcdjr\" title=\"Master sszcdjr\" class=\"rated-user user-orange\">sszcdjr</a> →\r\n <a href=\"/blog/entry/119859\">Codeforces Round 896 (Div. 1, Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/119880\">It's Happening! Meta Hacker Cup 2023 Schedule</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/DaviddeGea1\" title=\"Expert DaviddeGea1\" class=\"rated-user user-blue\">DaviddeGea1</a> →\r\n <a href=\"/blog/entry/70917\">Number of ways of dividing an array into 2 parts such that sum of each part is > k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bekh\" title=\"Master Bekh\" class=\"rated-user user-orange\">Bekh</a> →\r\n <a href=\"/blog/entry/74245\">Questions and doubts regarding Aliens DP trick</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a> →\r\n <a href=\"/blog/entry/8192\">Codeforces Round #190 — Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/hocky\" title=\"Candidate Master hocky\" class=\"rated-user user-violet\">hocky</a> →\r\n <a href=\"/blog/entry/95323\">FBHC wuining uw Day? Incwease uw stacc size! (ㅅ´ ˘ `)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/liouzhou_101\" title=\"International Master liouzhou_101\" class=\"rated-user user-orange\">liouzhou_101</a> →\r\n <a href=\"/blog/entry/87598\">Editorial of Codeforces Round #700</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/yeon_gist\" title=\"Newbie yeon_gist\" class=\"rated-user user-gray\">yeon_gist</a> →\r\n <a href=\"/blog/entry/121170\">plusMinusPermutation computing error</a>\r\n <img alt=\"Text created or updated\" title=\"Text created or updated\" src=\"//codeforces.org/s/81027/images/icons/x-update-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/altforminuscontribution\" title=\"Newbie altforminuscontribution\" class=\"rated-user user-gray\">altforminuscontribution</a> →\r\n <a href=\"/blog/entry/121162\">My screen get unexpectedly big, what should I do</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/atcoder_official\" title=\"Unrated, atcoder_official\" class=\"rated-user user-black\">atcoder_official</a> →\r\n <a href=\"/blog/entry/121120\">We will hold UNIQUE VISION Programming Contest 2023 Autumn(AtCoder Beginner Contest 323)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/YouStill_DontKnowMeYet\" title=\"Candidate Master YouStill_DontKnowMeYet\" class=\"rated-user user-violet\">YouStill_DontKnowMeYet</a> →\r\n <a href=\"/blog/entry/117659\">[GYM] Al-Baath Collegiate Programming Contest 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/ankancool\" title=\"Expert ankancool\" class=\"rated-user user-blue\">ankancool</a> →\r\n <a href=\"/blog/entry/121136\">Invitation to AstroByte 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/GeZhiyuan\" title=\"Grandmaster GeZhiyuan\" class=\"rated-user user-red\">GeZhiyuan</a> →\r\n <a href=\"/blog/entry/120943\">Codeforces Round 901 (Div. 1, Div. 2) Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a> →\r\n <a href=\"/blog/entry/120772\">PSA: Increase your stack size before the Meta Hacker Cup, here's how</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/dino_merlin\" title=\"Expert dino_merlin\" class=\"rated-user user-blue\">dino_merlin</a> →\r\n <a href=\"/blog/entry/121145\">Intuitive approach for CEOI Kangaroo?</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/icecuber\" title=\"Grandmaster icecuber\" class=\"rated-user user-red\">icecuber</a> →\r\n <a href=\"/blog/entry/70018\">CSES DP section editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bn00b\" title=\"Newbie Bn00b\" class=\"rated-user user-gray\">Bn00b</a> →\r\n <a href=\"/blog/entry/98820\">[FEATURE REQUEST : ATCODER] TOPICS TAGS AND SORTING BY SOLVE COUNT</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a> →\r\n <a href=\"/blog/entry/121163\">AtCoder Regular Contest 166 Announcement</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/windva\" title=\"Grandmaster windva\" class=\"rated-user user-red\">windva</a> →\r\n <a href=\"/blog/entry/120644\">Codeforces Round 899 (Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Misa-Misa\" title=\"Expert Misa-Misa\" class=\"rated-user user-blue\">Misa-Misa</a> →\r\n <a href=\"/blog/entry/121157\">Someone please help me understand this.</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/shivam565\" title=\"Specialist shivam565\" class=\"rated-user user-cyan\">shivam565</a> →\r\n <a href=\"/blog/entry/108348\">Total number of subarrays with sum atmost k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n </ul>\r\n </div>\r\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/recent-actions\">Detailed →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n</div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li><a\r\n href=\"/profile/gridnevvvit\">gridnevvvit</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/gridnevvvit\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/gridnevvvit\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/gridnevvvit\">Submissions</a></li>\r\n <li><a\r\n href=\"/groups/with/gridnevvvit\">Groups</a></li>\r\n <li><a\r\n href=\"/contests/with/gridnevvvit\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/gridnevvvit\">Problemsetting</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/gridnevvvit\" style=\"text-decoration:none;color:black !important;\">gridnevvvit's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"10638\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/10583\"> <p>Editorial Codeforces Round #227 (Div. 2)</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/gridnevvvit\" title=\"Candidate Master gridnevvvit\" class=\"rated-user user-violet\">gridnevvvit</a>,\r\n <span class=\"format-humantime\" title=\"Jan/30/2014 22:21\">10 years ago</span>,\r\n translation,\r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><h3><a href=\"/contest/387/problem/A\" title=\"Codeforces Round 227 (Div. 2)\">387A - George and Sleep</a></h3><p>I will describe the simple solution. Let George woke up in the <span class=\"tex-span\"><i>h</i><sub class=\"lower-index\">0</sub></span> hours and <span class=\"tex-span\"><i>m</i><sub class=\"lower-index\">0</sub></span> minutes, and he slept for <span class=\"tex-span\"><i>h</i><sub class=\"lower-index\">1</sub></span> hours and <span class=\"tex-span\"><i>m</i><sub class=\"lower-index\">1</sub></span> minutes. Let's get the number <span class=\"tex-span\"><i>h</i><sub class=\"lower-index\"><i>p</i></sub> = <i>h</i><sub class=\"lower-index\">0</sub> - <i>h</i><sub class=\"lower-index\">1</sub></span> and <span class=\"tex-span\"><i>m</i><sub class=\"lower-index\"><i>p</i></sub> = <i>m</i><sub class=\"lower-index\">0</sub> - <i>m</i><sub class=\"lower-index\">1</sub></span>. If <span class=\"tex-span\"><i>m</i><sub class=\"lower-index\"><i>p</i></sub> < 0</span>, then you should add to <span class=\"tex-span\"><i>m</i><sub class=\"lower-index\"><i>p</i></sub></span> <span class=\"tex-span\">60</span> minutes and subtract from <span class=\"tex-span\"><i>h</i><sub class=\"lower-index\"><i>p</i></sub></span> one hour. After that if <span class=\"tex-span\"><i>h</i><sub class=\"lower-index\"><i>p</i></sub> < 0</span>, then add to it <span class=\"tex-span\">24</span> hours. You can print the answer in C++ by using the following line:</p> <pre><code>printf("%02d:%02d", h[p], m[p]).\n</code></pre><p>The complexity is <span class=\"tex-span\"><i>O</i>(1)</span> time and <span class=\"tex-span\"><i>O</i>(1)</span> memory.</p><p>Author's solution: <a href=\"/contest/387/submission/5850831\" title=\"Submission 5850831 by gridnevvvit\">5850831</a></p><h3><a href=\"/contest/387/problem/B\" title=\"Codeforces Round 227 (Div. 2)\">387B - George and Round</a></h3><p>Consider the number of requirements of the difficulties, which we will cover, and we will come up with and prepare new problem to cover other requirements. It is clear that if we decided to meet the <span class=\"tex-span\"><i>i</i></span> out of <span class=\"tex-span\"><i>n</i></span> requirements, it would be better to take those with minimal complexity. Let's simplify <span class=\"tex-span\"><i>i</i></span> most difficult problems to lightest requirements. If all goes well, then we update the answer by value <span class=\"tex-span\"><i>n</i> - <i>i</i></span>.</p><p>The complexity is: <span class=\"tex-span\"><i>O</i>(<i>n</i><sup class=\"upper-index\">2</sup>)</span> time / <span class=\"tex-span\"><i>O</i>(<i>n</i>)</span> memory. Note, that there is an solution with complexity <span class=\"tex-span\"><i>O</i>(<i>n</i> + <i>m</i>)</span>.</p><p>Author's solution: <a href=\"/contest/387/submission/5850888\" title=\"Submission 5850888 by gridnevvvit\">5850888</a></p><h3><a href=\"/contest/387/problem/C\" title=\"Codeforces Round 227 (Div. 2)\">387C - George and Number</a></h3><p>Let's obtain the following irreducible representation of a number <span class=\"tex-span\"><i>p</i> = <i>a</i><sub class=\"lower-index\">1</sub> + <i>a</i><sub class=\"lower-index\">2</sub> + ... + <i>a</i><sub class=\"lower-index\"><i>k</i></sub></span>, where <span class=\"tex-span\"> + </span> is a concatenation, and numbers <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> have the form <span class=\"tex-span\"><i>x</i>00..000</span> (x — is non zero digit, and after that there are only zeroes). Let's determine largest index <span class=\"tex-span\"><i>i</i></span>, such that <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub> + <i>a</i><sub class=\"lower-index\">2</sub> + ... + <i>a</i><sub class=\"lower-index\"><i>i</i> - 1</sub> < <i>a</i><sub class=\"lower-index\"><i>i</i></sub></span>. If there are no such index <span class=\"tex-span\"><i>i</i></span> then <span class=\"tex-span\"><i>i</i> = 1</span>. After that is <span class=\"tex-span\"><i>k</i> - <i>i</i> + 1</span>. You can compare numbers by using length of number and first digit. You can prove these solution as home task : )</p><p>The complexity is: <span class=\"tex-span\"><i>O</i>(<i>n</i>)</span> time / <span class=\"tex-span\"><i>O</i>(<i>n</i>)</span> memory.</p><p>Author's solution: <a href=\"/contest/387/submission/5850919\" title=\"Submission 5850919 by gridnevvvit\">5850919</a></p><h3><a href=\"/contest/387/problem/D\" title=\"Codeforces Round 227 (Div. 2)\">387D - George and Interesting Graph</a></h3><p>To solve this problem you should know about bipartite matching.</p><p>Let's consider the center of graph <span class=\"tex-span\"><i>i</i></span>. After that let's remove arcs that have form <span class=\"tex-span\">(<i>i</i>, <i>u</i>)</span> or <span class=\"tex-span\">(<i>u</i>, <i>i</i>)</span>. Let's there are <span class=\"tex-span\"><i>cntWithI</i></span> arcs of such type. Let's <span class=\"tex-span\"><i>Other</i> = <i>m</i> - <i>CntWithI</i></span> — number of other arcs.</p><p>After that we should found maximal bipartite matching on the bipartite graph. This graph has following idea: left part of this graph is indegrees of all vertexes except vertex <span class=\"tex-span\"><i>i</i></span>, right part of this graph is outdegrees of all vertexes except vertex <span class=\"tex-span\"><i>i</i></span>. Also if there an arc <span class=\"tex-span\">(<i>i</i>, <i>j</i>)</span> in our graph then in our bipartite graph there an arc <span class=\"tex-span\">(<i>i</i>, <i>j</i>)</span>, where <span class=\"tex-span\"><i>i</i></span> — vertex from left part, <span class=\"tex-span\"><i>j</i></span> — vertex from the right part. Let's size of bipartite matching on the bipartite graph equals to <span class=\"tex-span\"><i>leng</i></span>. Then answer for the current vertex <span class=\"tex-span\"><i>i</i></span> equals to <span class=\"tex-span\">2<i>n</i> - 1 - <i>cntWithI</i> + <i>Other</i> - <i>leng</i> + (<i>n</i> - 1) - <i>leng</i></span>. After that you should update global answer. Why it is correct? It is simple to understand that if we will found bipartite matching on the bipartite graph we will cover maximal number of requirements on in/out degrees. Because of that, we will remove all other arcs, except of maximal matching, and after that we will add this maximal matching to full matching by adding <span class=\"tex-span\">(<i>n</i> - 1) - <i>leng</i></span> arcs. Note, it is important, that self-loops are not forbidden. Withoud self-loops problem is very hard, I think. </p><p>The complexity is: <span class=\"tex-span\"><i>O</i>(<i>n</i><sup class=\"upper-index\">2</sup><i>m</i>)</span> time / <span class=\"tex-span\"><i>O</i>(<i>n</i> + <i>m</i>)</span> memory.</p><p><a href=\"/contest/387/submission/5850946\" title=\"Submission 5850946 by gridnevvvit\">5850946</a></p><h3><a href=\"/contest/387/problem/E\" title=\"Codeforces Round 227 (Div. 2)\">387E - George and Cards</a></h3><p>Let's calculate arrays <span class=\"tex-span\"><i>pos</i>[<i>i</i>]</span> — position of number <span class=\"tex-span\"><i>i</i></span> in permutation <span class=\"tex-span\"><i>p</i></span> and <span class=\"tex-span\"><i>need</i>[<i>i</i>]</span> — equals to one if we should remove number <span class=\"tex-span\"><i>i</i></span> from permutation <span class=\"tex-span\"><i>p</i></span>, and zero if we shouldn't remove <span class=\"tex-span\"><i>i</i></span> from permutation <span class=\"tex-span\"><i>p</i></span>. </p><p>Let's <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub>, <i>a</i><sub class=\"lower-index\">2</sub>, ..., <i>a</i><sub class=\"lower-index\"><i>n</i> - <i>k</i></sub></span> — numvers, which we should remove. It is clear to understand that we should remove these number in increasing order. It is simple to proof this statement.</p><p>Let's iterate <span class=\"tex-span\"><i>i</i></span> from to <span class=\"tex-span\">1</span> to <span class=\"tex-span\"><i>n</i></span>. Also we the current number we will have special set (set <>in с++, TreeSet in Java) of positions of non-erased numbers (which are smaller then <span class=\"tex-span\"><i>i</i></span>) of permutation. These position can create an ``obstacle'' for current position of number <span class=\"tex-span\"><i>i</i></span>. It is simple to support this special set. Also we can add to this set numbers <span class=\"tex-span\"> - 1</span> and <span class=\"tex-span\"><i>n</i></span>. Now it is easy to find length og the maximal sub-array, where current number is a minimum. You can prosess such query by using standart functions of programming language (lower and higher in Java). After that we should use Fenwick tree to determine quantity of numbers which are not removed on the maximal sub-array.</p><p>The complexity is: <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/5e7dae7c1838af7ba7570bdf02ff61029b043be6.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> time / <span class=\"tex-span\"><i>O</i>(<i>n</i>)</span> memory.</p><p>Very simple implementation on Java: <a href=\"/contest/387/submission/5850986\" title=\"Submission 5850986 by gridnevvvit\">5850986</a></p></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/387\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 227 (Div. 2)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-6883-10638\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"6883\",\n blogEntryId: \"10583\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n <div style=\"font-size: 1.1rem;line-height: 11px;\">\r\n <img style=\"vertical-align: middle;\" src=\"//codeforces.org/s/81027/images/blog/tags.png\" title=\"Tags\" alt=\"Tags\"/>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=editorial\" class=\"tag notice\" style=\"text-decoration: none;\">editorial</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=codeforces\" class=\"tag notice\" style=\"text-decoration: none;\">codeforces</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=round\" class=\"tag notice\" style=\"text-decoration: none;\">round</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=227\" class=\"tag notice\" style=\"text-decoration: none;\">227</a>\r\n </span>\r\n </div>\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-10638\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+35</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-10638\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/gridnevvvit\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/gridnevvvit\">\n gridnevvvit\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Jan/30/2014 22:21\">10 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/10583#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/10583#comments\">\n 25\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"10654\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (25)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159495\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/coolbun\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/coolbun\" title=\"Candidate Master coolbun\" class=\"rated-user user-violet\">coolbun</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/30/2014 22:54\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159495\" href=\"?#comment-159495\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159495\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"2\"\r\n data-commentUserId=\"90437\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+2</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159495\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can anyone explain the solution of problem C</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159495 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159495 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159495\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159552\" commentParentId=\"159495\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/prakhar3agrwal\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/45384/avatar/63c5e4d25f17da6b.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/prakhar3agrwal\" title=\"Expert prakhar3agrwal\" class=\"rated-user user-blue\">prakhar3agrwal</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/31/2014 14:13\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159552\" href=\"?#comment-159552\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159495\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159552\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"45384\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159552\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Well my approach to this question was different , just start from the beginning and take 2 string variables. Let the variables be g and l (for global and local resp.),now g will store the substring starting from the beginning till just before the index from where l started.Now if the next character is '0' then we are bound to include it in the local string otherwise just see that whether g>=l or not , if yes then increase ans by 1 and include l in g (g+=l) and clear l, else make ans=1, g=g+l and clear l. This is because if g<l then obviously the substring in l should occur before g in resultant substring (meaning it will be "lg" instead of "gl"). Finally print the ans........</p><p>Hope it helps.... </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159552 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159552 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159552\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159577\" commentParentId=\"159552\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/eddycael\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/52186/avatar/a0efb238d6a68050.jpg'/> </a>\n <div><a href=\"/profile/eddycael\" title=\"Specialist eddycael\" class=\"rated-user user-cyan\">eddycael</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/31/2014 20:53\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159577\" href=\"?#comment-159577\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159552\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159577\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"52186\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159577\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Hello, (sorry for my poor english) My solution traverses the string with 2 pointers and whenever it encounters a string representing a smaller number than what's left then add 1 to the answer. It is not necessary to generate any substrings... Just analyze the representation of strings of equal length. Here's my solution: <a href=\"//codeforces.com/contest/387/submission/5858084\">solutionECMC</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159577 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159577 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159577\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159740\" commentParentId=\"159577\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/prakhar3agrwal\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/45384/avatar/63c5e4d25f17da6b.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/prakhar3agrwal\" title=\"Expert prakhar3agrwal\" class=\"rated-user user-blue\">prakhar3agrwal</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2014 08:26\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159740\" href=\"?#comment-159740\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159577\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159740\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"45384\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159740\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I am not generating any substring as such , it was the concept used in my solution, my time complexity is O(n).</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159740 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159740 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159740\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159553\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/jibon_ebong_shomoy\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/107227/avatar/d1546e81b26787b3.jpg'/> </a>\n <div><a href=\"/profile/jibon_ebong_shomoy\" title=\"Specialist jibon_ebong_shomoy\" class=\"rated-user user-cyan\">jibon_ebong_shomoy</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/31/2014 14:52\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159553\" href=\"?#comment-159553\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"159553\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"159553\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"107227\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159553\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I don't understand the solution of D . can anyone explain? what to do? why the last part of answer <code>(n-1)-leng</code> for?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159553 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159553 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159553\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159566\" commentParentId=\"159553\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/gridnevvvit\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/31163/avatar/db500a30a0b0a6f1.jpg'/> </a>\n <div><a href=\"/profile/gridnevvvit\" title=\"Candidate Master gridnevvvit\" class=\"rated-user user-violet\">gridnevvvit</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/31/2014 17:12\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159566\" href=\"?#comment-159566\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159553\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159566\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"31163\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159566\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>We will add some arcs to create prefect matching in graph</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159566 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159566 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159566\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"335415\" commentParentId=\"159553\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/u33how\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/216525/avatar/a0f0155335a1dd88.jpg'/> </a>\n <div><a href=\"/profile/u33how\" title=\"Expert u33how\" class=\"rated-user user-blue\">u33how</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/04/2017 17:52\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-335415\" href=\"?#comment-335415\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159553\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"335415\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"216525\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-335415\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I think the equation came from these :</p><p>ans = 2*(n-1); // for adding the (u,i)and(i,u) edges</p><p>ans = ans — (cntWithI) ; // they were already given, so we do not need to delete them,</p><p>ans = ans+1 ; // the center must have a self loop according to problem description.</p><p>ans = ans + Others ; // delete all the extra edges;</p><p>ans = ans — leng ; // do not have to delete the matching edges</p><p>ans = ans+ (n-1) ; // add n-1 self loops</p><p>ans = ans-leng ; // 'leng' number of vertices do not need self loop; </p><p>Hope it helps somebody.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-335415 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-335415 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-335415\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159679\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/raylee\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/135528/avatar/52549c9492fe7c04.jpg'/> </a>\n <div><a href=\"/profile/raylee\" title=\"Specialist raylee\" class=\"rated-user user-cyan\">raylee</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/02/2014 11:07\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159679\" href=\"?#comment-159679\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"159679\" revisionCount=\"13\" revision=\"13\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">13</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"159679\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"135528\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159679\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In the problem D, said "The complexity is: <span class=\"tex-span\"><i>O</i>(<i>n</i><sup class=\"upper-index\">2</sup> <i>m</i>)</span> time." But n and m (2 ≤ n ≤ 500, 1 ≤ m ≤ 1000). Can you explain why this complexity wont TLE? thank you.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159679 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159679 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159679\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159685\" commentParentId=\"159679\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/gridnevvvit\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/31163/avatar/db500a30a0b0a6f1.jpg'/> </a>\n <div><a href=\"/profile/gridnevvvit\" title=\"Candidate Master gridnevvvit\" class=\"rated-user user-violet\">gridnevvvit</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/02/2014 11:55\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159685\" href=\"?#comment-159685\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159679\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159685\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"31163\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159685\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Yes. First, let's calculate number of operations: it is about <span class=\"tex-span\">2 * 10<sup class=\"upper-index\">8</sup></span>. It is not so much. If you have good implementation of Kuhn, it would pass. Also, I know, that number of operation is much lower than <span class=\"tex-span\">2 * 10<sup class=\"upper-index\">8</sup></span>.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159685 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159685 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159685\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159689\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/1nikhil9\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/60595/avatar/64f85d0070290be7.jpg'/> </a>\n <div><a href=\"/profile/1nikhil9\" title=\"Candidate Master 1nikhil9\" class=\"rated-user user-violet\">1nikhil9</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/02/2014 14:07\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159689\" href=\"?#comment-159689\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159689\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"60595\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159689\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Test case 4 for Problem D says N = 153, M = 392. But there are only 391 edges in the input file.</p><p><a href=\"//codeforces.com/contest/387/submission/5868021\">http://codeforces.com/contest/387/submission/5868021</a></p><p>Am I misunderstanding something? Thanks.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159689 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159689 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159689\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159694\" commentParentId=\"159689\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/gridnevvvit\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/31163/avatar/db500a30a0b0a6f1.jpg'/> </a>\n <div><a href=\"/profile/gridnevvvit\" title=\"Candidate Master gridnevvvit\" class=\"rated-user user-violet\">gridnevvvit</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/02/2014 15:06\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159694\" href=\"?#comment-159694\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159689\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159694\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"31163\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159694\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Testcase is valid.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159694 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159694 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159694\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"160860\" commentParentId=\"159694\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/khrak\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/128936/avatar/6d9b38f723c23a83.jpg'/> </a>\n <div><a href=\"/profile/khrak\" title=\"Expert khrak\" class=\"rated-user user-blue\">khrak</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/07/2014 20:07\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-160860\" href=\"?#comment-160860\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159694\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"160860\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"128936\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-160860\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>What does n variable mean in C problem tutorial? </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-160860 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-160860 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-160860\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"160876\" commentParentId=\"160860\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/gridnevvvit\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/31163/avatar/db500a30a0b0a6f1.jpg'/> </a>\n <div><a href=\"/profile/gridnevvvit\" title=\"Candidate Master gridnevvvit\" class=\"rated-user user-violet\">gridnevvvit</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/08/2014 00:57\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-160876\" href=\"?#comment-160876\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-160860\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"160876\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"31163\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-160876\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>n is the length of the number from the input.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-160876 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-160876 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-160876\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"160894\" commentParentId=\"160876\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/khrak\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/128936/avatar/6d9b38f723c23a83.jpg'/> </a>\n <div><a href=\"/profile/khrak\" title=\"Expert khrak\" class=\"rated-user user-blue\">khrak</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/08/2014 11:15\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-160894\" href=\"?#comment-160894\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-160876\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"160894\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"128936\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-160894\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>So, for 800101 we have a1 = 800, a2 = 10, a3 = 1, and n = 6. what value has i for this example, 1 or -1? </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-160894 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-160894 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-160894\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"160913\" commentParentId=\"160894\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/gridnevvvit\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/31163/avatar/db500a30a0b0a6f1.jpg'/> </a>\n <div><a href=\"/profile/gridnevvvit\" title=\"Candidate Master gridnevvvit\" class=\"rated-user user-violet\">gridnevvvit</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/08/2014 14:34\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-160913\" href=\"?#comment-160913\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-160894\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"160913\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"31163\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-160913\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>i equals to -1. I understood, that there is an small mistake: answer is <span class=\"tex-span\"><i>k</i> - <i>i</i> + 1</span></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-160913 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-160913 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-160913\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"160924\" commentParentId=\"160913\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/khrak\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/128936/avatar/6d9b38f723c23a83.jpg'/> </a>\n <div><a href=\"/profile/khrak\" title=\"Expert khrak\" class=\"rated-user user-blue\">khrak</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/08/2014 16:02\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-160924\" href=\"?#comment-160924\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-160913\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"160924\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"128936\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-160924\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Sorry for so many questions, but I can't still understand how we count answer answer for 800101. here k equals 3, i equals -1 (as you said), then answer should be k — i + 1 = 3 — (-1) + 1 = 5 when answer here is 3.. What I didn't understand correctly? </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-160924 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-160924 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-160924\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"160928\" commentParentId=\"160924\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/gridnevvvit\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/31163/avatar/db500a30a0b0a6f1.jpg'/> </a>\n <div><a href=\"/profile/gridnevvvit\" title=\"Candidate Master gridnevvvit\" class=\"rated-user user-violet\">gridnevvvit</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/08/2014 17:23\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-160928\" href=\"?#comment-160928\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-160924\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"160928\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"31163\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-160928\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Oh, it's my mistake. If there is no such index, index i should be equals to 1, yes.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-160928 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-160928 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-160928\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"160929\" commentParentId=\"160928\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/khrak\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/128936/avatar/6d9b38f723c23a83.jpg'/> </a>\n <div><a href=\"/profile/khrak\" title=\"Expert khrak\" class=\"rated-user user-blue\">khrak</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/08/2014 17:27\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-160929\" href=\"?#comment-160929\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-160928\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"160929\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"128936\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-160929\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Okey. Then I understand and I'll think about proof. Thank you! :) </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-160929 en true\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-160929 en true\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-160929\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"161379\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/rohitjv\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/107177/avatar/3326d08f28613bd4.jpg'/> </a>\n <div><a href=\"/profile/rohitjv\" title=\"Expert rohitjv\" class=\"rated-user user-blue\">rohitjv</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/12/2014 21:33\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-161379\" href=\"?#comment-161379\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"161379\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"107177\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-161379\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In problem C, the definition of the array <em>need[i]</em> in the description does not match with the code provided. The actual definition of <em>need[i]</em> should be : need[i] — equals to <strong>0</strong> if we should remove number i from permutation p, and <strong>1</strong> if we shouldn't remove i from permutation p. Please correct me if I am wrong.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-161379 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-161379 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-161379\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"161380\" commentParentId=\"161379\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/gridnevvvit\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/31163/avatar/db500a30a0b0a6f1.jpg'/> </a>\n <div><a href=\"/profile/gridnevvvit\" title=\"Candidate Master gridnevvvit\" class=\"rated-user user-violet\">gridnevvvit</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/12/2014 21:56\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-161380\" href=\"?#comment-161380\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-161379\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"161380\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"31163\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-161380\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Yes, description does not match with the code provided. There are only ideas in editorial, so there are can be differences. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-161380 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-161380 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-161380\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"161811\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Nakochi\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/101746/avatar/ccfafe3f7587f95d.jpg'/> </a>\n <div><a href=\"/profile/Nakochi\" title=\"Expert Nakochi\" class=\"rated-user user-blue\">Nakochi</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/17/2014 18:23\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-161811\" href=\"?#comment-161811\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"161811\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"101746\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-161811\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Problem C is really a challenge for me!!! Orz!!!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-161811 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-161811 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-161811\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"161820\" commentParentId=\"161811\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Nodir.Daminov\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/71439/avatar/d6d2016f6dfe5ecd.jpg'/> </a>\n <div><a href=\"/profile/Nodir.Daminov\" title=\"Candidate Master Nodir.Daminov\" class=\"rated-user user-violet\">Nodir.Daminov</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/17/2014 19:19\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-161820\" href=\"?#comment-161820\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-161811\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"161820\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"71439\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-161820\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Who cares ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-161820 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-161820 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-161820\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"161902\" commentParentId=\"161820\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Nakochi\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/101746/avatar/ccfafe3f7587f95d.jpg'/> </a>\n <div><a href=\"/profile/Nakochi\" title=\"Expert Nakochi\" class=\"rated-user user-blue\">Nakochi</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/18/2014 18:14\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-161902\" href=\"?#comment-161902\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-161820\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"161902\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"101746\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-161902\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Sorry, I misunderstood the problem. Now it's much easier. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-161902 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-161902 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-161902\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"161903\" commentParentId=\"161902\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Nodir.Daminov\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/71439/avatar/d6d2016f6dfe5ecd.jpg'/> </a>\n <div><a href=\"/profile/Nodir.Daminov\" title=\"Candidate Master Nodir.Daminov\" class=\"rated-user user-violet\">Nodir.Daminov</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/18/2014 18:25\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-161903\" href=\"?#comment-161903\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-161902\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"161903\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"71439\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-161903\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Who cares ???</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-161903 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-161903 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-161903\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"161904\" commentParentId=\"161903\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Nakochi\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/101746/avatar/ccfafe3f7587f95d.jpg'/> </a>\n <div><a href=\"/profile/Nakochi\" title=\"Expert Nakochi\" class=\"rated-user user-blue\">Nakochi</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/18/2014 18:54\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-161904\" href=\"?#comment-161904\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-161903\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"161904\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"101746\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-161904\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Seems you care. :D</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-161904 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-161904 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-161904\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n <br/>\r\n\r\n<div id=\"editBox-10654\" style=\"width:50em;display:none;\">\r\n <div class=\"previewBody\" style=\"border: 1px solid #d4d4d4; margin-bottom: 0.5em; padding: 0.25em; display:none;\"> </div>\r\n <div style=\"width: 1px\"> </div>\r\n <div class=\"commentLocale\" style=\"position: relative; top: 0.5em;left:4px;display: none;\">\r\n <input type=\"radio\" name=\"locale\" value=\"en\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In English</span>\r\n <input style=\"margin-left:1em\" type=\"radio\" name=\"locale\" value=\"ru\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In Russian</span>\r\n </div>\r\n <textarea data-drafts-id=\"CommentReplyFrame\" class=\"wysiwyg\" name=\"editContent\" rows=\"20\" style=\"width:99%;\"></textarea>\r\n <div class=\"error error__content\"></div>\r\n <div style=\"text-align:center;\">\r\n <input type=\"button\" name=\"preview\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Preview\"/>\r\n <input type=\"button\" name=\"save\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Save\"/>\r\n </div>\r\n</div>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n\r\nvar firstPreview10654 = true;\r\nvar lastPreviewContent10654 = '';\r\n\r\nif (!window.moveCommentRevision) {\r\n moveCommentRevision = function(e, dir) {\r\n var p = e.parent();\r\n var revisionCount = parseInt(p.attr(\"revisionCount\"));\r\n var revision = parseInt(p.attr(\"revision\"));\r\n var next = revision + dir;\r\n var commentId = p.attr(\"commentId\");\r\n if (next >= 1 && next <= revisionCount) {\r\n $.post(\r\n \"/data/comment-data\",\r\n {action: \"revision\", commentId: commentId, revision: next},\r\n function(json) {\r\n if (json.success == \"true\") {\r\n var parentDiv = e;\r\n\r\n while (parentDiv !== null && (parentDiv[0].nodeName.toLowerCase() !== \"td\" || !parentDiv.hasClass(\"right\"))) {\r\n parentDiv = parentDiv.parent();\r\n }\r\n\r\n if (parentDiv === null) {\r\n return;\r\n }\r\n\r\n parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\").html(json.content);\r\n Codeforces.setupSpoilers(parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\"));\r\n p.attr(\"revision\", next);\r\n p.find(\"span.revision\").text(next);\r\n if (next == 1) {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"visible\");\r\n }\r\n if (next == revisionCount) {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"visible\");\r\n }\r\n\r\n window.updateTypography();\r\n MathJax.Hub.Typeset();\r\n } else {\r\n alert(e.error);\r\n }\r\n },\r\n \"json\"\r\n );\r\n }\r\n };\r\n}\r\n\r\n$(\"div[commentableId=10654] a.leftRevision\").click(function () {\r\n window.moveCommentRevision($(this), -1);\r\n return false;\r\n});\r\n\r\n$(\"div[commentableId=10654] a.rightRevision\").click(function () {\r\n window.moveCommentRevision($(this), +1);\r\n return false;\r\n});\r\n\r\n\r\n\r\n });\n </script>\n\r\n\r\n <script src=\"//codeforces.org/s/81027/js/swfobject-2.2.min.js\" type=\"text/javascript\"></script>\n <script src=\"//codeforces.org/s/81027/js/ftaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n if (window.evercookie) {\n var ec = new evercookie({\n history: false,\n silverlight: false,\n baseurl: '',\n asseturi: '/assets',\n phpuri: '/2fdcd78',\n pngPath: '/eps',\n etagPath: '/ees',\n cachePath: '/ecs'\n });\n\n var randomNumber = function () {\n return Math.random().toString(36).substr(2);\n };\n\n var randomToken = function () {\n return (randomNumber() + randomNumber()).substring(0, 18);\n };\n\n window._ftaa = \"\";\n\n ec.get(\"70a7c28f3de\", function (value) {\n window._ftaa = value;\n if (!window._ftaa) {\n window._ftaa = randomToken();\n ec.set(\"70a7c28f3de\", window._ftaa);\n }\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n } else {\n window._ftaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\n <script src=\"//codeforces.org/s/81027/js/bfaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n var fpCallback = function() {\n Fingerprint2.get({}, function(components) {\n window._bfaa = Fingerprint2.x64hash128(components.map(function (pair) { return pair.value }).join(), 31);\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n };\n if (typeof Fingerprint2 !== 'undefined') {\n if (window.requestIdleCallback) {\n requestIdleCallback(fpCallback)\n } else {\n setTimeout(fpCallback, 500)\n }\n } else {\n window._bfaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"a.new-root-comment\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n\r\n $(\".comment-table .reply a\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".vote-for-comment\").mouseover(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").mouseout(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").click(function () {\r\n var vote = $(this);\r\n var commentId = $(this).parent().attr(\"commentid\");\r\n var commentRating = $(this).parent().attr(\"data-commentRating\");\r\n var direction = $(this).attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n $.post(\"/data/comment/vote\", {commentId: commentId, _tta: Codeforces.tta(), vote: direction, commentRating: commentRating}, function(data) {\r\n if (direction != 0 && !ownComment && data[\"success\"] == \"true\") {\r\n vote.parent().find(\".vote-for-comment\").attr(\"voteDirection\", 0);\r\n if (direction == 1)\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n else {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.closest(\".CommentVoteFrame\").find(\".ComplaintFrame\").css(\"display\", \"inline-block\");\r\n }\r\n vote.find(\"img\").attr(\"popacity\", \"1.0\");\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n vote.parent().find(\".commentRating\").html(data[\"commentRating\"]);\r\n }\r\n Codeforces.showMessage(data[\"message\"]);\r\n }, \"json\");\r\n return false;\r\n });\r\n\r\n $(\".negative-comment-vote\").closest(\".comment-table\").addClass(\"comment-bad\");\r\n\r\n $(\".troll-comment-vote\").closest(\".comment\").css(\"display\", \"none\");\r\n\r\n $(\".too-negative-comment-vote\").closest(\".comment-table\").each(function () {\r\n var e = $(this);\r\n e.addClass(\"comment-too-bad\");\r\n var commentId = e.attr(\"commentId\");\r\n $(\"<div class='bad-comment-replacement ttypography'>The comment is hidden because of too negative feedback, click <a href=# class=show-bad-comment-link>here</a> to view it</div>\").appendTo(\r\n e.find(\".right\")\r\n );\r\n e.find(\".comment-content\").hide();\r\n e.find(\".show-bad-comment-link\").click(function () {\r\n e.find(\".comment-content\").show();\r\n e.find(\".bad-comment-replacement\").hide();\r\n return false;\r\n });\r\n });\r\n });\n </script>\n </div>\r\n\r\n <style type=\"text/css\">\r\n .new-comments-box {\r\n padding: 0.5em;\r\n width: 22px;\r\n font-size: 1.3rem;\r\n font-weight: bold !important;\r\n\r\n position: fixed;\r\n top: 40%;\r\n right: 0;\r\n opacity: 0.2;\r\n color: white;\r\n text-align: center;\r\n\r\n border: 1px solid #222;\r\n background-color: #888 !important;\r\n border-radius: 3px;\r\n -moz-border-radius: 3px;\r\n -webkit-border-radius: 3px;\r\n }\r\n\r\n .new-comments-box:hover {\r\n opacity: 1;\r\n }\r\n\r\n .new-comments-box .dir:hover {\r\n background: #3B5998 !important;\r\n cursor: pointer;\r\n }\r\n </style>\r\n\r\n <div class=\"new-comments-box\" data-position=\"outside\" data-index=\"-1\" style=\"display: none;\">\r\n <div class=\"up dir\" title=\"Ctrl+Up\">↑<hr/>\r\n </div>\r\n <div class=\"info\" title=\"New comments\"></div>\r\n <div class=\"down dir\" title=\"Ctrl+Down\">\r\n <hr/>↓\r\n </div>\r\n </div>\r\n\r\n <script>\r\n $(\".show-archived-checkbox\").change(function () {\r\n const checked = $(this).is(\":checked\");\r\n $.post(\"/data/comment-data\", {action: \"setShowArchived\", checked}, function (json) {\r\n if (json[\"success\"] !== \"true\") {\r\n alert(json[\"error\"]);\r\n } else {\r\n if (checked) {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are now displayed\")\r\n } else {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are no longer displayed\")\r\n }\r\n }\r\n });\r\n return false;\r\n });\r\n\r\n function gotoComment(direction) {\r\n var box = $(\".new-comments-box\");\r\n var index = parseInt(box.attr(\"data-index\"));\r\n if (index == -1)\r\n index = 0;\r\n else\r\n index = Math.max(0, Math.min(parseInt(box.find(\".info\").text()) - 1, index + direction));\r\n box.attr(\"data-index\", index);\r\n var comment = $($(\".comment .highlight-blue[commentId]\").get(index));\r\n $('html, body').animate({\r\n 'scrollTop': Math.max(0, comment.offset().top - ($(window).height() - comment.height()) / 2)\r\n });\r\n return false;\r\n }\r\n\r\n $(\".new-comments-box .down\").click(function () {\r\n return gotoComment(1);\r\n });\r\n\r\n $(\".new-comments-box .up\").click(function () {\r\n return gotoComment(-1);\r\n });\r\n\r\n $(document).keydown(function (e) {\r\n var code = (e.keyCode ? e.keyCode : e.which);\r\n if (e.ctrlKey) {\r\n if (code == 38 || code == 40) {\r\n gotoComment(code - 39);\r\n }\r\n }\r\n });\r\n\r\n var newCommentCount = $(\".comment .highlight-blue[commentId]\").length;\r\n if (newCommentCount > 0) {\r\n $(\".new-comments-box .info\").text(newCommentCount);\r\n $(\".new-comments-box\").show();\r\n }\r\n\r\n $('table.comment-table').mouseenter(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").addClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n\r\n $('table.comment-table').mouseleave(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").removeClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n </script>\r\n\r\n\r\n\r\n <script>\r\n function adjustTopicComplainFrames() {\r\n let topicIds = [];\r\n\r\n $(\".has-topic-id\").each(function () {\r\n const $this = $(this);\r\n const topicId = $this.attr(\"topicId\");\r\n if (topicId) {\r\n topicIds.push(topicId);\r\n }\r\n });\r\n\r\n $.post(\"/data/topics\", {\r\n action: \"findComplainableTopicIds\",\r\n topicIds: topicIds.join(\",\")\r\n }, function (json) {\r\n if (json[\"success\"] === \"true\") {\r\n for (const topicId of json[\"complainableTopicIds\"].split(\",\")) {\r\n $(\".has-topic-id[topicId=\" + topicId + \"]\").each(function () {\r\n $(this).find(\".meta .ComplaintFrame\").css(\"display\", \"inline-block\");\r\n });\r\n }\r\n }\r\n }, \"json\");\r\n }\r\n\r\n $(function () {\r\n adjustTopicComplainFrames();\r\n })\r\n </script>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-10638\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 10638, _tta: Codeforces.tta(), topicRevisionId: 37197, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-10638\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 10638, _tta: Codeforces.tta(), topicRevisionId: 37197, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n </div>\r\n </div>\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 22:13:05</span> (h1).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/81027/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/81027/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/81027/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/81027/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-81027.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'812875999be52de2',t:'MTY5NjcwNTk4NS43NTIwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"}}},{"rowIdx":1955,"cells":{"problem_id":{"kind":"string","value":"387C"},"contest":{"kind":"string","value":"387"},"problem":{"kind":"string","value":"C"},"lang":{"kind":"string","value":"en"},"problem_title":{"kind":"string","value":"C. George and Number"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">C. George and Number</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>George is a cat, so he really likes to play. Most of all he likes to play with his array of positive integers <span class=\"tex-span\"><i>b</i></span>. During the game, George modifies the array by using special changes. Let's mark George's current array as <span class=\"tex-span\"><i>b</i><sub class=\"lower-index\">1</sub>, <i>b</i><sub class=\"lower-index\">2</sub>, ..., <i>b</i><sub class=\"lower-index\">|<i>b</i>|</sub></span> (record <span class=\"tex-span\">|<i>b</i>|</span> denotes the current length of the array). Then one change is a sequence of actions: </p><ul> <li> Choose two distinct indexes <span class=\"tex-span\"><i>i</i></span> and <span class=\"tex-span\"><i>j</i></span> <span class=\"tex-span\">(1 ≤ <i>i</i>, <i>j</i> ≤ |<i>b</i>|; <i>i</i> ≠ <i>j</i>)</span>, such that <span class=\"tex-span\"><i>b</i><sub class=\"lower-index\"><i>i</i></sub> ≥ <i>b</i><sub class=\"lower-index\"><i>j</i></sub></span>. </li><li> Get number <span class=\"tex-span\"><i>v</i> = <i>concat</i>(<i>b</i><sub class=\"lower-index\"><i>i</i></sub>, <i>b</i><sub class=\"lower-index\"><i>j</i></sub>)</span>, where <span class=\"tex-span\"><i>concat</i>(<i>x</i>, <i>y</i>)</span> is a number obtained by adding number <span class=\"tex-span\"><i>y</i></span> to the end of the decimal record of number <span class=\"tex-span\"><i>x</i></span>. For example, <span class=\"tex-span\"><i>concat</i>(500, 10) = 50010</span>, <span class=\"tex-span\"><i>concat</i>(2, 2) = 22</span>. </li><li> Add number <span class=\"tex-span\"><i>v</i></span> to the end of the array. The length of the array will increase by one. </li><li> Remove from the array numbers with indexes <span class=\"tex-span\"><i>i</i></span> and <span class=\"tex-span\"><i>j</i></span>. The length of the array will decrease by two, and elements of the array will become re-numbered from <span class=\"tex-span\">1</span> to current length of the array. </li></ul><p>George played for a long time with his array <span class=\"tex-span\"><i>b</i></span> and received from array <span class=\"tex-span\"><i>b</i></span> an array consisting of exactly one number <span class=\"tex-span\"><i>p</i></span>. Now George wants to know: what is the maximum number of elements array <span class=\"tex-span\"><i>b</i></span> could contain originally? Help him find this number. Note that originally the array could contain only <span class=\"tex-font-style-bf\">positive</span> integers.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line of the input contains a single integer <span class=\"tex-span\"><i>p</i></span> (<span class=\"tex-span\">1 ≤ <i>p</i> < 10<sup class=\"upper-index\">100000</sup></span>). It is guaranteed that number <span class=\"tex-span\"><i>p</i></span> doesn't contain any leading zeroes.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print an integer — the maximum number of elements array <span class=\"tex-span\"><i>b</i></span> could contain originally.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>9555<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>4</pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>10000000005<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>2</pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>800101<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>3</pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>45<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1</pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>1000000000000001223300003342220044555<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>17</pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>19992000<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1</pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>310200<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>2</pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>Let's consider the test examples: </p><ul> <li> Originally array <span class=\"tex-span\"><i>b</i></span> can be equal to <span class=\"tex-span\">{5, 9, 5, 5}</span>. The sequence of George's changes could have been: <span class=\"tex-span\">{5, 9, 5, 5} → {5, 5, 95} → {95, 55} → {9555}</span>. </li><li> Originally array <span class=\"tex-span\"><i>b</i></span> could be equal to <span class=\"tex-span\">{1000000000, 5}</span>. Please note that the array <span class=\"tex-span\"><i>b</i></span> cannot contain zeros. </li><li> Originally array <span class=\"tex-span\"><i>b</i></span> could be equal to <span class=\"tex-span\">{800, 10, 1}</span>. </li><li> Originally array <span class=\"tex-span\"><i>b</i></span> could be equal to <span class=\"tex-span\">{45}</span>. It cannot be equal to <span class=\"tex-span\">{4, 5}</span>, because George can get only array <span class=\"tex-span\">{54}</span> from this array in one operation. </li></ul><p>Note that the numbers can be very large.</p></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"639b8d35ba3bf20497ff2b39ca7406bf\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - C - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"1d8414af0a90e113b8a49898336bf2bc6a1719bc\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - C - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/73366/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/73366/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/73366/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/73366/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/73366/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/73366/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/73366/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/73366/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/73366/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/73366/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/73366/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/73366/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/73366/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/73366/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/sidebar-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/a037fe51637846d9c7c725713cd840ea/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='639b8d35ba3bf20497ff2b39ca7406bf'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/73366/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/73366/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fcontest%2F387%2Fproblem%2FC%3Flocale%3Den\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"current\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='639b8d35ba3bf20497ff2b39ca7406bf'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:100%;\"><a style=\"color: black\" href=\"/contest/387\">Codeforces Round 227 (Div. 2)</a></th>\n </tr>\n <tr>\n <td class=\"left bottom\" colspan=\"1\"><span class=\"contest-state-phase\">Finished</span></td>\n </tr>\n </tbody>\n </table>\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Practice?\n <div class=\"top-links\">\n </div>\n </div>\n<div>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Want to solve the contest problems after the official contest ends? Just register for practice and you will be able to submit solutions.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"\" method=\"post\"><input type='hidden' name='csrf_token' value='639b8d35ba3bf20497ff2b39ca7406bf'/>\r\n <input type=\"hidden\" name=\"action\" value=\"registerForPractice\"/>\r\n <input type=\"submit\" name=\"submit\" value=\"Register for practice\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div> \r\n</div>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox ContestVirtualFrame borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Virtual participation <i class=\"sidebar-caption-icon las la-angle-down\"></i>\r\n\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\" \"\r\n\r\n data-page-url=\"/data/sidebarFrames\"\r\n\r\n>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests.\n\nIf you've seen these problems, a virtual contest is not for you - solve these problems in the archive.\n\nIf you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.\n\nNever use someone else's code, read the tutorials or communicate with other person during a virtual contest.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"/contest/387/virtual\" method=\"get\">\r\n <input type=\"submit\" name=\"submit\" value=\"Start virtual contest\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div>\r\n</div>\r\n <script>\r\n $(function () {\r\n $(\".ContestVirtualFrame .sidebar-caption-icon\").click(function() {\r\n $(this).toggleClass(\"la-angle-down la-angle-right\");\r\n const $target = $(this).parent().next();\r\n $target.toggle();\r\n const dataPageUrl = $target.attr(\"data-page-url\");\r\n const collapsed = $(this).hasClass(\"la-angle-right\");\r\n const params = {\r\n action: \"setCollapsed\",\r\n sidebarFrameSimpleClassName: \"ContestVirtualFrame\",\r\n collapsed\r\n };\r\n $.each($target[0].attributes, function(i, a) {\r\n const name = a.name;\r\n if (name.startsWith(\"data-extra-key-\")) {\r\n const key = a.value;\r\n const keyIndex = parseInt(name.substring(\"data-extra-key-\".length));\r\n const value = $target.attr(\"data-extra-value-\" + keyIndex);\r\n params[key] = value;\r\n }\r\n });\r\n $.post(dataPageUrl, params, function (result) {\r\n if (result[\"success\"] !== \"true\") {\r\n Codeforces.showMessage(\"Failed to save collapsed state.\");\r\n }\r\n }, \"json\");\r\n return false;\r\n });\r\n })\r\n </script>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Problem tags\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Greedy algorithms\">\r\n greedy\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Implementation problems, programming technics, simulation\">\r\n implementation\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Difficulty\">\r\n *1700\r\n</span>\r\n </div>\n <div style=\"clear:both;text-align:right;font-size:1.1rem;\">\r\n <span title=\"Please login into the Codeforces\" class=\"notice\">No tag edit access</span>\r\n </div>\r\n</div>\r\n </div>\n\r\n<form id=\"addTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='639b8d35ba3bf20497ff2b39ca7406bf'/>\r\n <input name=\"action\" type=\"hidden\" value=\"addTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"6208\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<form id=\"removeTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='639b8d35ba3bf20497ff2b39ca7406bf'/>\r\n <input name=\"action\" type=\"hidden\" value=\"removeTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"6208\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<script type=\"text/javascript\">\r\n $(\".tag-box img\").click(function () {\r\n var tagName = $(this).attr(\"value\");\r\n Codeforces.confirm(\"Are you sure you want to remove this tag?\", function () {\r\n $(\"#removeTagForm input[name=tagName]\").val(tagName);\r\n $(\"#removeTagForm\").submit();\r\n }, function () {\r\n }, \"Yes\", \"No\");\r\n });\r\n\r\n $(\"#addTagLink\").click(function () {\r\n $(this).hide();\r\n $(\"#addTagLabel\").show();\r\n return false;\r\n });\r\n\r\n $(\"#addTagSelect\").change(function () {\r\n var tagName = $(this).val();\r\n if (tagName === \"\") {\r\n $(\"#addTagLabel\").hide();\r\n $(\"#addTagLink\").show();\r\n } else {\r\n $(\"#addTagForm input[name=tagName]\").val(tagName);\r\n $(\"#addTagForm\").submit();\r\n }\r\n });\r\n</script>\r\n\r\n<style type=\"text/css\">\r\n#new-resource-form tr td {\r\npadding-top: 0.5em;\r\n}\r\n#new-resource-form input:not([type=\"submit\"]) {\r\nfont-size: 0.8em;\r\n}\r\n#new-resource-form select {\r\nfont-size: 0.8em;\r\n}\r\n.new-resource-error {\r\nfont-size: 0.8em;\r\n}\r\n.resource-locale {\r\ncolor: #666;\r\nfont-family: Consolas, \"Andale Mono WT\", \"Andale Mono\", \"Lucida Console\", \"Lucida Sans Typewriter\", \"DejaVu Sans Mono\", \"Bitstream Vera Sans Mono\", \"Liberation Mono\", \"Nimbus Mono L\", Monaco, \"Courier New\", Courier, monospace;\r\n}\r\n</style>\r\n<div class=\"roundbox sidebox sidebar-menu borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Contest materials\n<div class=\"top-links\">\n</div>\n</div>\n<ul>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/10569\" title=\"Codeforces Round #227 (Div. 2)\" target=\"_blank\">Announcement</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"2176:2182\" resourceName=\"Announcement\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/10583\" title=\"Editorial Codeforces Round #227 (Div. 2)\" target=\"_blank\">Tutorial</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"2177:2183\" resourceName=\"Tutorial\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n</ul>\r\n</div></div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li class=\"current selectedLava\"><a\r\n href=\"/contest/387\">Problems</a></li>\r\n <li><a\r\n href=\"/contest/387/submit\">Submit Code</a></li>\r\n <li><a\r\n href=\"/contest/387/my\">My Submissions</a></li>\r\n <li><a\r\n href=\"/contest/387/status\">Status</a></li>\r\n <li><a\r\n href=\"/contest/387/hacks\">Hacks</a></li>\r\n <li><a\r\n href=\"/contest/387/room/1\">Room</a></li>\r\n <li><a\r\n href=\"/contest/387/standings\">Standings</a></li>\r\n <li><a\r\n href=\"/contest/387/customtest\">Custom Invocation</a></li>\r\n</ul>\r\n</div>\n\r\n <style>\r\n #facebox .content:has(.diff-popup) {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n }\r\n\r\n .testCaseMarker {\r\n position: absolute;\r\n font-weight: bold;\r\n font-size: 1rem;\r\n }\r\n\r\n .diff-popup {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n display: none;\r\n overflow: auto;\r\n }\r\n\r\n .input-output-copier {\r\n font-size: 1.2rem;\r\n float: right;\r\n color: #888 !important;\r\n cursor: pointer;\r\n border: 1px solid rgb(185, 185, 185);\r\n padding: 3px;\r\n margin: 1px;\r\n line-height: 1.1rem;\r\n text-transform: none;\r\n }\r\n\r\n .input-output-copier:hover {\r\n background-color: #def;\r\n }\r\n\r\n .test-explanation textarea {\r\n width: 100%;\r\n height: 1.5em;\r\n }\r\n\r\n .pending-submission-message {\r\n color: darkorange !important;\r\n }\r\n </style>\r\n <script>\r\n const OPENING_SPACE = String.fromCharCode(1001);\r\n const CLOSING_SPACE = String.fromCharCode(1002);\r\n\r\n const nodeToText = function (node, pre) {\r\n let result = [];\r\n\r\n if (node.tagName === \"SCRIPT\" || node.tagName === \"math\"\r\n || (node.classList && node.classList.contains(\"input-output-copier\")))\r\n return [];\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(OPENING_SPACE);\r\n }\r\n\r\n if (node.nodeType === Node.TEXT_NODE) {\r\n let s = node.textContent;\r\n if (!pre) {\r\n s = s.replace(/\\s+/g, \" \");\r\n }\r\n if (s.length > 0) {\r\n result.push(s);\r\n }\r\n }\r\n\r\n if (pre && node.tagName === \"BR\") {\r\n result.push(\"\\n\");\r\n }\r\n\r\n node.childNodes.forEach(function (child) {\r\n result.push(nodeToText(child, node.tagName === \"PRE\").join(\"\"));\r\n });\r\n\r\n if (node.tagName === \"DIV\"\r\n || node.tagName === \"P\"\r\n || node.tagName === \"PRE\"\r\n || node.tagName === \"UL\"\r\n || node.tagName === \"LI\"\r\n ) {\r\n result.push(\"\\n\");\r\n }\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(CLOSING_SPACE);\r\n }\r\n\r\n return result;\r\n }\r\n\r\n const isSpecial = function (c) {\r\n return c === ',' || c === '.' || c === ';' || c === ')' || c === ' ';\r\n }\r\n\r\n const convertStatementToText = function(statmentNode) {\r\n const text = nodeToText(statmentNode, false).join(\"\").replace(/ +/g, \" \").replace(/\\n\\n+/g, \"\\n\\n\");\r\n let result = [];\r\n for (let i = 0; i < text.length; i++) {\r\n const c = text.charAt(i);\r\n if (c === OPENING_SPACE) {\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"C\" data-uuid=\"ps_f6e0efbc2b27b60dcc1c178a0451e7e838ef5134\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">C. George and Number</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>George is a cat, so he really likes to play. Most of all he likes to play with his array of positive integers <span class=\"tex-span\"><i>b</i></span>. During the game, George modifies the array by using special changes. Let's mark George's current array as <span class=\"tex-span\"><i>b</i><sub class=\"lower-index\">1</sub>, <i>b</i><sub class=\"lower-index\">2</sub>, ..., <i>b</i><sub class=\"lower-index\">|<i>b</i>|</sub></span> (record <span class=\"tex-span\">|<i>b</i>|</span> denotes the current length of the array). Then one change is a sequence of actions: </p><ul> <li> Choose two distinct indexes <span class=\"tex-span\"><i>i</i></span> and <span class=\"tex-span\"><i>j</i></span> <span class=\"tex-span\">(1 ≤ <i>i</i>, <i>j</i> ≤ |<i>b</i>|; <i>i</i> ≠ <i>j</i>)</span>, such that <span class=\"tex-span\"><i>b</i><sub class=\"lower-index\"><i>i</i></sub> ≥ <i>b</i><sub class=\"lower-index\"><i>j</i></sub></span>. </li><li> Get number <span class=\"tex-span\"><i>v</i> = <i>concat</i>(<i>b</i><sub class=\"lower-index\"><i>i</i></sub>, <i>b</i><sub class=\"lower-index\"><i>j</i></sub>)</span>, where <span class=\"tex-span\"><i>concat</i>(<i>x</i>, <i>y</i>)</span> is a number obtained by adding number <span class=\"tex-span\"><i>y</i></span> to the end of the decimal record of number <span class=\"tex-span\"><i>x</i></span>. For example, <span class=\"tex-span\"><i>concat</i>(500, 10) = 50010</span>, <span class=\"tex-span\"><i>concat</i>(2, 2) = 22</span>. </li><li> Add number <span class=\"tex-span\"><i>v</i></span> to the end of the array. The length of the array will increase by one. </li><li> Remove from the array numbers with indexes <span class=\"tex-span\"><i>i</i></span> and <span class=\"tex-span\"><i>j</i></span>. The length of the array will decrease by two, and elements of the array will become re-numbered from <span class=\"tex-span\">1</span> to current length of the array. </li></ul><p>George played for a long time with his array <span class=\"tex-span\"><i>b</i></span> and received from array <span class=\"tex-span\"><i>b</i></span> an array consisting of exactly one number <span class=\"tex-span\"><i>p</i></span>. Now George wants to know: what is the maximum number of elements array <span class=\"tex-span\"><i>b</i></span> could contain originally? Help him find this number. Note that originally the array could contain only <span class=\"tex-font-style-bf\">positive</span> integers.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line of the input contains a single integer <span class=\"tex-span\"><i>p</i></span> (<span class=\"tex-span\">1 ≤ <i>p</i> < 10<sup class=\"upper-index\">100000</sup></span>). It is guaranteed that number <span class=\"tex-span\"><i>p</i></span> doesn't contain any leading zeroes.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print an integer — the maximum number of elements array <span class=\"tex-span\"><i>b</i></span> could contain originally.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>9555<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>4</pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>10000000005<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>2</pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>800101<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>3</pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>45<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1</pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>1000000000000001223300003342220044555<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>17</pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>19992000<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1</pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>310200<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>2</pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>Let's consider the test examples: </p><ul> <li> Originally array <span class=\"tex-span\"><i>b</i></span> can be equal to <span class=\"tex-span\">{5, 9, 5, 5}</span>. The sequence of George's changes could have been: <span class=\"tex-span\">{5, 9, 5, 5} → {5, 5, 95} → {95, 55} → {9555}</span>. </li><li> Originally array <span class=\"tex-span\"><i>b</i></span> could be equal to <span class=\"tex-span\">{1000000000, 5}</span>. Please note that the array <span class=\"tex-span\"><i>b</i></span> cannot contain zeros. </li><li> Originally array <span class=\"tex-span\"><i>b</i></span> could be equal to <span class=\"tex-span\">{800, 10, 1}</span>. </li><li> Originally array <span class=\"tex-span\"><i>b</i></span> could be equal to <span class=\"tex-span\">{45}</span>. It cannot be equal to <span class=\"tex-span\">{4, 5}</span>, because George can get only array <span class=\"tex-span\">{54}</span> from this array in one operation. </li></ul><p>Note that the numbers can be very large.</p></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=C]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== statementText) {\r\n $problem.find(\".diff-notifier\").show();\r\n\r\n $problem.find(\".diff-notifier-close\").click(function() {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n $problem.find(\".diff-notifier\").hide();\r\n });\r\n\r\n $problem.find(\"a.view-changes\").click(function() {\r\n $.post(\"/data/diff\", {action: \"getDiff\", a: previousStatementText, b: statementText}, function (result) {\r\n if (result[\"success\"] === \"true\") {\r\n Codeforces.facebox(\".diff-popup\", \"//codeforces.org/s/73366\");\r\n $(\"#facebox .diff-popup\").html(result[\"diff\"]);\r\n }\r\n }, \"json\");\r\n });\r\n }\r\n } else {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n }\r\n });\r\n });\r\n </script>\r\n\r\n\r\n<script type=\"text/javascript\">\r\n $(document).ready(function () {\r\n window.changedTests = new Set();\r\n\r\n function endsWith(string, suffix) {\r\n return string.indexOf(suffix, string.length - suffix.length) !== -1;\r\n }\r\n\r\n const inputFileDiv = $(\"div.input-file\");\r\n const inputFile = inputFileDiv.text();\r\n const outputFileDiv = $(\"div.output-file\");\r\n const outputFile = outputFileDiv.text();\r\n\r\n\r\n if (!endsWith(inputFile, \"standard input\")\r\n && !endsWith(inputFile, \"standard input\")) {\r\n inputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n if (!endsWith(outputFile, \"standard output\")\r\n && !endsWith(outputFile, \"standard output\")) {\r\n outputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n const titleDiv = $(\"div.header div.title\");\r\n\r\n\r\n\r\n String.prototype.replaceAll = function (search, replace) {\r\n return this.split(search).join(replace);\r\n };\r\n\r\n $(\".sample-test .title\").each(function () {\r\n const preId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n const cpyId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n\r\n $(this).parent().find(\"pre\").attr(\"id\", preId);\r\n const $copy = $(\"<div title='Copy' data-clipboard-target='#\" + preId + \"' id='\" + cpyId + \"' class='input-output-copier'>Copy</div>\");\r\n $(this).append($copy);\r\n\r\n const clipboard = new Clipboard('#' + cpyId, {\r\n text: function (trigger) {\r\n const pre = document.querySelector('#' + preId);\r\n const lines = pre.querySelectorAll(\".test-example-line\");\r\n return Codeforces.filterClipboardText(pre.innerText, lines.length);\r\n }\r\n });\r\n\r\n const isInput = $(this).parent().hasClass(\"input\");\r\n\r\n clipboard.on('success', function (e) {\r\n if (isInput) {\r\n Codeforces.showMessage(\"The example input has been copied into the clipboard\");\r\n } else {\r\n Codeforces.showMessage(\"The example output has been copied into the clipboard\");\r\n }\r\n e.clearSelection();\r\n });\r\n });\r\n\r\n $(\".test-form-item input\").change(function () {\r\n addPendingSubmissionMessage($($(this).closest(\"form\")), \"You changed the answer, do not forget to submit it if you want to save the changes\");\r\n const index = $(this).closest(\".problemindexholder\").attr(\"problemindex\");\r\n let test = \"\";\r\n $(this).closest(\"form input\").each(function () {\r\n const test_ = $(this).attr(\"name\");\r\n if (test_ && test_.substring(0, 4) === \"test\") {\r\n test = test_;\r\n }\r\n });\r\n if (index.length > 0 && test.length > 0) {\r\n const indexTest = index + \"::\" + test;\r\n window.changedTests.add(indexTest);\r\n }\r\n });\r\n\r\n $(window).on('beforeunload', function () {\r\n if (window.changedTests.size > 0) {\r\n return 'Dialog text here';\r\n }\r\n });\r\n\r\n autosize($('.test-explanation textarea'));\r\n\r\n $(\".test-example-line\").hover(function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n let top = 1E20;\r\n let left = 1E20;\r\n let problem = $(this).closest(\".problemindexholder\");\r\n $(this).closest(\".input\").find(\".\" + clazz).css(\"background-color\", \"#FFFDE7\").each(function() {\r\n top = Math.min(top, $(this).offset().top);\r\n left = Math.min(left, $(this).offset().left);\r\n });\r\n let testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n if (testCaseMarker.length === 0) {\r\n const html = \"<div class=\\\"testCaseMarker testCaseMarker_\" + end + \" notice\\\"></div>\";\r\n problem.append($(html));\r\n testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n }\r\n if (testCaseMarker) {\r\n testCaseMarker.show()\r\n .offset({top, left: left - 20})\r\n .text(end);\r\n }\r\n }\r\n }\r\n });\r\n }, function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n $(\".\" + clazz).css(\"background-color\", \"\");\r\n $(this).closest(\".problemindexholder\").find(\".testCaseMarker_\" + end).hide();\r\n }\r\n }\r\n });\r\n });\r\n\r\n });\r\n</script>\r\n\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 05:38:25</span> (j3).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/73366/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/73366/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/73366/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/73366/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-73366.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'8122c4902b094975',t:'MTY5NjY0NjMwNS40NDQwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"},"long_tags":{"kind":"string","value":"[\"Greedy algorithms\", \"Implementation problems, programming technics, simulation\"]"},"short_tags":{"kind":"string","value":"[\"greedy\", \"implementation\", \"*1700\"]"},"tutorial_link":{"kind":"string","value":"https://codeforces.com/blog/entry/10583"},"tutorial_page":{"kind":"string","value":"\r\n\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"36a5cb4572cb122db333ec3b9f88364a\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"h1\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Editorial Codeforces Round #227 (Div. 2) - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n \n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Editorial Codeforces Round #227 (Div. 2) - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/81027/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/81027/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/81027/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/81027/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/81027/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/81027/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/81027/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/81027/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/81027/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/81027/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/81027/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/81027/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/81027/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/81027/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/573cedc6b04c15481941f418269f4057/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='36a5cb4572cb122db333ec3b9f88364a'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/81027/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fblog%2Fentry%2F10583\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='36a5cb4572cb122db333ec3b9f88364a'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Pay attention\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n <div style=\"text-align:center;border-bottom: 1px solid rgb(185, 185, 185);margin:0 -0.5em 0.5em -0.5em;padding: 0 1em 0.5em 1em;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 1, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:51:56</span><br/><a href=\"/contestRegistration/1876\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n <div style=\"text-align:center;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 2, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:51:56</span><br/><a href=\"/contestRegistration/1877\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n\r\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div>\r\n\r\n\n <div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\n\r\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='36a5cb4572cb122db333ec3b9f88364a'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n </label>\r\n </div>\r\n <div style=\"padding: 0 1em 1em 1em;text-align:right;\">\r\n <input style=\"height:1.65em;padding:0 0.75em;\" type=\"submit\" value=\"Find\"/>\r\n </div>\r\n </form>\r\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".handleBox\").autocomplete(\"/data/handles\", {\r\n delay: 200,\r\n width: 200,\r\n selectFirst: false,\r\n matchContains: true,\r\n minChars: 3\r\n });\r\n $(\".handleForm\").attr(\"autocomplete\", \"off\").submit(function () {\r\n var link = \"/profile/userHandle\".replace(\r\n \"userHandle\", $(this).find(\".handleBox\").val()\r\n );\r\n window.location = link;\r\n return false;\r\n });\r\n });\n </script>\n\r\n\r\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Recent actions\n <div class=\"top-links\">\n </div>\n </div>\n <div class=\"recent-actions\">\r\n <ul>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/121073\">Meta Hacker Cup 2023 Round 1</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/.Danet\" title=\"Expert .Danet\" class=\"rated-user user-blue\">.Danet</a> →\r\n <a href=\"/blog/entry/121172\">[TLE on pretest1]</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\" class=\"rated-user user-red\">Pyqe</a> →\r\n <a href=\"/blog/entry/121025\">Codeforces Round #902 (Div. 1, Div. 2, based on COMPFEST 15 — Final Round)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pranshu_Pandya\" title=\"Specialist Pranshu_Pandya\" class=\"rated-user user-cyan\">Pranshu_Pandya</a> →\r\n <a href=\"/blog/entry/121171\">An Interesting Tree Problem</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/sszcdjr\" title=\"Master sszcdjr\" class=\"rated-user user-orange\">sszcdjr</a> →\r\n <a href=\"/blog/entry/119859\">Codeforces Round 896 (Div. 1, Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/119880\">It's Happening! Meta Hacker Cup 2023 Schedule</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/DaviddeGea1\" title=\"Expert DaviddeGea1\" class=\"rated-user user-blue\">DaviddeGea1</a> →\r\n <a href=\"/blog/entry/70917\">Number of ways of dividing an array into 2 parts such that sum of each part is > k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bekh\" title=\"Master Bekh\" class=\"rated-user user-orange\">Bekh</a> →\r\n <a href=\"/blog/entry/74245\">Questions and doubts regarding Aliens DP trick</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a> →\r\n <a href=\"/blog/entry/8192\">Codeforces Round #190 — Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/hocky\" title=\"Candidate Master hocky\" class=\"rated-user user-violet\">hocky</a> →\r\n <a href=\"/blog/entry/95323\">FBHC wuining uw Day? Incwease uw stacc size! (ㅅ´ ˘ `)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/liouzhou_101\" title=\"International Master liouzhou_101\" class=\"rated-user user-orange\">liouzhou_101</a> →\r\n <a href=\"/blog/entry/87598\">Editorial of Codeforces Round #700</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/yeon_gist\" title=\"Newbie yeon_gist\" class=\"rated-user user-gray\">yeon_gist</a> →\r\n <a href=\"/blog/entry/121170\">plusMinusPermutation computing error</a>\r\n <img alt=\"Text created or updated\" title=\"Text created or updated\" src=\"//codeforces.org/s/81027/images/icons/x-update-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/altforminuscontribution\" title=\"Newbie altforminuscontribution\" class=\"rated-user user-gray\">altforminuscontribution</a> →\r\n <a href=\"/blog/entry/121162\">My screen get unexpectedly big, what should I do</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/atcoder_official\" title=\"Unrated, atcoder_official\" class=\"rated-user user-black\">atcoder_official</a> →\r\n <a href=\"/blog/entry/121120\">We will hold UNIQUE VISION Programming Contest 2023 Autumn(AtCoder Beginner Contest 323)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/YouStill_DontKnowMeYet\" title=\"Candidate Master YouStill_DontKnowMeYet\" class=\"rated-user user-violet\">YouStill_DontKnowMeYet</a> →\r\n <a href=\"/blog/entry/117659\">[GYM] Al-Baath Collegiate Programming Contest 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/ankancool\" title=\"Expert ankancool\" class=\"rated-user user-blue\">ankancool</a> →\r\n <a href=\"/blog/entry/121136\">Invitation to AstroByte 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/GeZhiyuan\" title=\"Grandmaster GeZhiyuan\" class=\"rated-user user-red\">GeZhiyuan</a> →\r\n <a href=\"/blog/entry/120943\">Codeforces Round 901 (Div. 1, Div. 2) Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a> →\r\n <a href=\"/blog/entry/120772\">PSA: Increase your stack size before the Meta Hacker Cup, here's how</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/dino_merlin\" title=\"Expert dino_merlin\" class=\"rated-user user-blue\">dino_merlin</a> →\r\n <a href=\"/blog/entry/121145\">Intuitive approach for CEOI Kangaroo?</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/icecuber\" title=\"Grandmaster icecuber\" class=\"rated-user user-red\">icecuber</a> →\r\n <a href=\"/blog/entry/70018\">CSES DP section editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bn00b\" title=\"Newbie Bn00b\" class=\"rated-user user-gray\">Bn00b</a> →\r\n <a href=\"/blog/entry/98820\">[FEATURE REQUEST : ATCODER] TOPICS TAGS AND SORTING BY SOLVE COUNT</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a> →\r\n <a href=\"/blog/entry/121163\">AtCoder Regular Contest 166 Announcement</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/windva\" title=\"Grandmaster windva\" class=\"rated-user user-red\">windva</a> →\r\n <a href=\"/blog/entry/120644\">Codeforces Round 899 (Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Misa-Misa\" title=\"Expert Misa-Misa\" class=\"rated-user user-blue\">Misa-Misa</a> →\r\n <a href=\"/blog/entry/121157\">Someone please help me understand this.</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/shivam565\" title=\"Specialist shivam565\" class=\"rated-user user-cyan\">shivam565</a> →\r\n <a href=\"/blog/entry/108348\">Total number of subarrays with sum atmost k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n </ul>\r\n </div>\r\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/recent-actions\">Detailed →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n</div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li><a\r\n href=\"/profile/gridnevvvit\">gridnevvvit</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/gridnevvvit\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/gridnevvvit\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/gridnevvvit\">Submissions</a></li>\r\n <li><a\r\n href=\"/groups/with/gridnevvvit\">Groups</a></li>\r\n <li><a\r\n href=\"/contests/with/gridnevvvit\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/gridnevvvit\">Problemsetting</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/gridnevvvit\" style=\"text-decoration:none;color:black !important;\">gridnevvvit's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"10638\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/10583\"> <p>Editorial Codeforces Round #227 (Div. 2)</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/gridnevvvit\" title=\"Candidate Master gridnevvvit\" class=\"rated-user user-violet\">gridnevvvit</a>,\r\n <span class=\"format-humantime\" title=\"Jan/30/2014 22:21\">10 years ago</span>,\r\n translation,\r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><h3><a href=\"/contest/387/problem/A\" title=\"Codeforces Round 227 (Div. 2)\">387A - George and Sleep</a></h3><p>I will describe the simple solution. Let George woke up in the <span class=\"tex-span\"><i>h</i><sub class=\"lower-index\">0</sub></span> hours and <span class=\"tex-span\"><i>m</i><sub class=\"lower-index\">0</sub></span> minutes, and he slept for <span class=\"tex-span\"><i>h</i><sub class=\"lower-index\">1</sub></span> hours and <span class=\"tex-span\"><i>m</i><sub class=\"lower-index\">1</sub></span> minutes. Let's get the number <span class=\"tex-span\"><i>h</i><sub class=\"lower-index\"><i>p</i></sub> = <i>h</i><sub class=\"lower-index\">0</sub> - <i>h</i><sub class=\"lower-index\">1</sub></span> and <span class=\"tex-span\"><i>m</i><sub class=\"lower-index\"><i>p</i></sub> = <i>m</i><sub class=\"lower-index\">0</sub> - <i>m</i><sub class=\"lower-index\">1</sub></span>. If <span class=\"tex-span\"><i>m</i><sub class=\"lower-index\"><i>p</i></sub> < 0</span>, then you should add to <span class=\"tex-span\"><i>m</i><sub class=\"lower-index\"><i>p</i></sub></span> <span class=\"tex-span\">60</span> minutes and subtract from <span class=\"tex-span\"><i>h</i><sub class=\"lower-index\"><i>p</i></sub></span> one hour. After that if <span class=\"tex-span\"><i>h</i><sub class=\"lower-index\"><i>p</i></sub> < 0</span>, then add to it <span class=\"tex-span\">24</span> hours. You can print the answer in C++ by using the following line:</p> <pre><code>printf("%02d:%02d", h[p], m[p]).\n</code></pre><p>The complexity is <span class=\"tex-span\"><i>O</i>(1)</span> time and <span class=\"tex-span\"><i>O</i>(1)</span> memory.</p><p>Author's solution: <a href=\"/contest/387/submission/5850831\" title=\"Submission 5850831 by gridnevvvit\">5850831</a></p><h3><a href=\"/contest/387/problem/B\" title=\"Codeforces Round 227 (Div. 2)\">387B - George and Round</a></h3><p>Consider the number of requirements of the difficulties, which we will cover, and we will come up with and prepare new problem to cover other requirements. It is clear that if we decided to meet the <span class=\"tex-span\"><i>i</i></span> out of <span class=\"tex-span\"><i>n</i></span> requirements, it would be better to take those with minimal complexity. Let's simplify <span class=\"tex-span\"><i>i</i></span> most difficult problems to lightest requirements. If all goes well, then we update the answer by value <span class=\"tex-span\"><i>n</i> - <i>i</i></span>.</p><p>The complexity is: <span class=\"tex-span\"><i>O</i>(<i>n</i><sup class=\"upper-index\">2</sup>)</span> time / <span class=\"tex-span\"><i>O</i>(<i>n</i>)</span> memory. Note, that there is an solution with complexity <span class=\"tex-span\"><i>O</i>(<i>n</i> + <i>m</i>)</span>.</p><p>Author's solution: <a href=\"/contest/387/submission/5850888\" title=\"Submission 5850888 by gridnevvvit\">5850888</a></p><h3><a href=\"/contest/387/problem/C\" title=\"Codeforces Round 227 (Div. 2)\">387C - George and Number</a></h3><p>Let's obtain the following irreducible representation of a number <span class=\"tex-span\"><i>p</i> = <i>a</i><sub class=\"lower-index\">1</sub> + <i>a</i><sub class=\"lower-index\">2</sub> + ... + <i>a</i><sub class=\"lower-index\"><i>k</i></sub></span>, where <span class=\"tex-span\"> + </span> is a concatenation, and numbers <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> have the form <span class=\"tex-span\"><i>x</i>00..000</span> (x — is non zero digit, and after that there are only zeroes). Let's determine largest index <span class=\"tex-span\"><i>i</i></span>, such that <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub> + <i>a</i><sub class=\"lower-index\">2</sub> + ... + <i>a</i><sub class=\"lower-index\"><i>i</i> - 1</sub> < <i>a</i><sub class=\"lower-index\"><i>i</i></sub></span>. If there are no such index <span class=\"tex-span\"><i>i</i></span> then <span class=\"tex-span\"><i>i</i> = 1</span>. After that is <span class=\"tex-span\"><i>k</i> - <i>i</i> + 1</span>. You can compare numbers by using length of number and first digit. You can prove these solution as home task : )</p><p>The complexity is: <span class=\"tex-span\"><i>O</i>(<i>n</i>)</span> time / <span class=\"tex-span\"><i>O</i>(<i>n</i>)</span> memory.</p><p>Author's solution: <a href=\"/contest/387/submission/5850919\" title=\"Submission 5850919 by gridnevvvit\">5850919</a></p><h3><a href=\"/contest/387/problem/D\" title=\"Codeforces Round 227 (Div. 2)\">387D - George and Interesting Graph</a></h3><p>To solve this problem you should know about bipartite matching.</p><p>Let's consider the center of graph <span class=\"tex-span\"><i>i</i></span>. After that let's remove arcs that have form <span class=\"tex-span\">(<i>i</i>, <i>u</i>)</span> or <span class=\"tex-span\">(<i>u</i>, <i>i</i>)</span>. Let's there are <span class=\"tex-span\"><i>cntWithI</i></span> arcs of such type. Let's <span class=\"tex-span\"><i>Other</i> = <i>m</i> - <i>CntWithI</i></span> — number of other arcs.</p><p>After that we should found maximal bipartite matching on the bipartite graph. This graph has following idea: left part of this graph is indegrees of all vertexes except vertex <span class=\"tex-span\"><i>i</i></span>, right part of this graph is outdegrees of all vertexes except vertex <span class=\"tex-span\"><i>i</i></span>. Also if there an arc <span class=\"tex-span\">(<i>i</i>, <i>j</i>)</span> in our graph then in our bipartite graph there an arc <span class=\"tex-span\">(<i>i</i>, <i>j</i>)</span>, where <span class=\"tex-span\"><i>i</i></span> — vertex from left part, <span class=\"tex-span\"><i>j</i></span> — vertex from the right part. Let's size of bipartite matching on the bipartite graph equals to <span class=\"tex-span\"><i>leng</i></span>. Then answer for the current vertex <span class=\"tex-span\"><i>i</i></span> equals to <span class=\"tex-span\">2<i>n</i> - 1 - <i>cntWithI</i> + <i>Other</i> - <i>leng</i> + (<i>n</i> - 1) - <i>leng</i></span>. After that you should update global answer. Why it is correct? It is simple to understand that if we will found bipartite matching on the bipartite graph we will cover maximal number of requirements on in/out degrees. Because of that, we will remove all other arcs, except of maximal matching, and after that we will add this maximal matching to full matching by adding <span class=\"tex-span\">(<i>n</i> - 1) - <i>leng</i></span> arcs. Note, it is important, that self-loops are not forbidden. Withoud self-loops problem is very hard, I think. </p><p>The complexity is: <span class=\"tex-span\"><i>O</i>(<i>n</i><sup class=\"upper-index\">2</sup><i>m</i>)</span> time / <span class=\"tex-span\"><i>O</i>(<i>n</i> + <i>m</i>)</span> memory.</p><p><a href=\"/contest/387/submission/5850946\" title=\"Submission 5850946 by gridnevvvit\">5850946</a></p><h3><a href=\"/contest/387/problem/E\" title=\"Codeforces Round 227 (Div. 2)\">387E - George and Cards</a></h3><p>Let's calculate arrays <span class=\"tex-span\"><i>pos</i>[<i>i</i>]</span> — position of number <span class=\"tex-span\"><i>i</i></span> in permutation <span class=\"tex-span\"><i>p</i></span> and <span class=\"tex-span\"><i>need</i>[<i>i</i>]</span> — equals to one if we should remove number <span class=\"tex-span\"><i>i</i></span> from permutation <span class=\"tex-span\"><i>p</i></span>, and zero if we shouldn't remove <span class=\"tex-span\"><i>i</i></span> from permutation <span class=\"tex-span\"><i>p</i></span>. </p><p>Let's <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub>, <i>a</i><sub class=\"lower-index\">2</sub>, ..., <i>a</i><sub class=\"lower-index\"><i>n</i> - <i>k</i></sub></span> — numvers, which we should remove. It is clear to understand that we should remove these number in increasing order. It is simple to proof this statement.</p><p>Let's iterate <span class=\"tex-span\"><i>i</i></span> from to <span class=\"tex-span\">1</span> to <span class=\"tex-span\"><i>n</i></span>. Also we the current number we will have special set (set <>in с++, TreeSet in Java) of positions of non-erased numbers (which are smaller then <span class=\"tex-span\"><i>i</i></span>) of permutation. These position can create an ``obstacle'' for current position of number <span class=\"tex-span\"><i>i</i></span>. It is simple to support this special set. Also we can add to this set numbers <span class=\"tex-span\"> - 1</span> and <span class=\"tex-span\"><i>n</i></span>. Now it is easy to find length og the maximal sub-array, where current number is a minimum. You can prosess such query by using standart functions of programming language (lower and higher in Java). After that we should use Fenwick tree to determine quantity of numbers which are not removed on the maximal sub-array.</p><p>The complexity is: <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/5e7dae7c1838af7ba7570bdf02ff61029b043be6.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> time / <span class=\"tex-span\"><i>O</i>(<i>n</i>)</span> memory.</p><p>Very simple implementation on Java: <a href=\"/contest/387/submission/5850986\" title=\"Submission 5850986 by gridnevvvit\">5850986</a></p></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/387\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 227 (Div. 2)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-6883-10638\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"6883\",\n blogEntryId: \"10583\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n <div style=\"font-size: 1.1rem;line-height: 11px;\">\r\n <img style=\"vertical-align: middle;\" src=\"//codeforces.org/s/81027/images/blog/tags.png\" title=\"Tags\" alt=\"Tags\"/>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=editorial\" class=\"tag notice\" style=\"text-decoration: none;\">editorial</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=codeforces\" class=\"tag notice\" style=\"text-decoration: none;\">codeforces</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=round\" class=\"tag notice\" style=\"text-decoration: none;\">round</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=227\" class=\"tag notice\" style=\"text-decoration: none;\">227</a>\r\n </span>\r\n </div>\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-10638\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+35</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-10638\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/gridnevvvit\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/gridnevvvit\">\n gridnevvvit\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Jan/30/2014 22:21\">10 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/10583#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/10583#comments\">\n 25\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"10654\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (25)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159495\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/coolbun\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/coolbun\" title=\"Candidate Master coolbun\" class=\"rated-user user-violet\">coolbun</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/30/2014 22:54\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159495\" href=\"?#comment-159495\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159495\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"2\"\r\n data-commentUserId=\"90437\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+2</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159495\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can anyone explain the solution of problem C</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159495 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159495 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159495\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159552\" commentParentId=\"159495\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/prakhar3agrwal\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/45384/avatar/63c5e4d25f17da6b.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/prakhar3agrwal\" title=\"Expert prakhar3agrwal\" class=\"rated-user user-blue\">prakhar3agrwal</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/31/2014 14:13\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159552\" href=\"?#comment-159552\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159495\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159552\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"45384\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159552\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Well my approach to this question was different , just start from the beginning and take 2 string variables. Let the variables be g and l (for global and local resp.),now g will store the substring starting from the beginning till just before the index from where l started.Now if the next character is '0' then we are bound to include it in the local string otherwise just see that whether g>=l or not , if yes then increase ans by 1 and include l in g (g+=l) and clear l, else make ans=1, g=g+l and clear l. This is because if g<l then obviously the substring in l should occur before g in resultant substring (meaning it will be "lg" instead of "gl"). Finally print the ans........</p><p>Hope it helps.... </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159552 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159552 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159552\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159577\" commentParentId=\"159552\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/eddycael\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/52186/avatar/a0efb238d6a68050.jpg'/> </a>\n <div><a href=\"/profile/eddycael\" title=\"Specialist eddycael\" class=\"rated-user user-cyan\">eddycael</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/31/2014 20:53\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159577\" href=\"?#comment-159577\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159552\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159577\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"52186\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159577\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Hello, (sorry for my poor english) My solution traverses the string with 2 pointers and whenever it encounters a string representing a smaller number than what's left then add 1 to the answer. It is not necessary to generate any substrings... Just analyze the representation of strings of equal length. Here's my solution: <a href=\"//codeforces.com/contest/387/submission/5858084\">solutionECMC</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159577 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159577 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159577\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159740\" commentParentId=\"159577\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/prakhar3agrwal\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/45384/avatar/63c5e4d25f17da6b.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/prakhar3agrwal\" title=\"Expert prakhar3agrwal\" class=\"rated-user user-blue\">prakhar3agrwal</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2014 08:26\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159740\" href=\"?#comment-159740\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159577\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159740\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"45384\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159740\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I am not generating any substring as such , it was the concept used in my solution, my time complexity is O(n).</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159740 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159740 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159740\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159553\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/jibon_ebong_shomoy\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/107227/avatar/d1546e81b26787b3.jpg'/> </a>\n <div><a href=\"/profile/jibon_ebong_shomoy\" title=\"Specialist jibon_ebong_shomoy\" class=\"rated-user user-cyan\">jibon_ebong_shomoy</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/31/2014 14:52\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159553\" href=\"?#comment-159553\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"159553\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"159553\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"107227\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159553\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I don't understand the solution of D . can anyone explain? what to do? why the last part of answer <code>(n-1)-leng</code> for?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159553 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159553 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159553\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159566\" commentParentId=\"159553\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/gridnevvvit\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/31163/avatar/db500a30a0b0a6f1.jpg'/> </a>\n <div><a href=\"/profile/gridnevvvit\" title=\"Candidate Master gridnevvvit\" class=\"rated-user user-violet\">gridnevvvit</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/31/2014 17:12\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159566\" href=\"?#comment-159566\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159553\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159566\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"31163\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159566\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>We will add some arcs to create prefect matching in graph</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159566 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159566 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159566\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"335415\" commentParentId=\"159553\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/u33how\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/216525/avatar/a0f0155335a1dd88.jpg'/> </a>\n <div><a href=\"/profile/u33how\" title=\"Expert u33how\" class=\"rated-user user-blue\">u33how</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/04/2017 17:52\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-335415\" href=\"?#comment-335415\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159553\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"335415\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"216525\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-335415\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I think the equation came from these :</p><p>ans = 2*(n-1); // for adding the (u,i)and(i,u) edges</p><p>ans = ans — (cntWithI) ; // they were already given, so we do not need to delete them,</p><p>ans = ans+1 ; // the center must have a self loop according to problem description.</p><p>ans = ans + Others ; // delete all the extra edges;</p><p>ans = ans — leng ; // do not have to delete the matching edges</p><p>ans = ans+ (n-1) ; // add n-1 self loops</p><p>ans = ans-leng ; // 'leng' number of vertices do not need self loop; </p><p>Hope it helps somebody.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-335415 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-335415 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-335415\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159679\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/raylee\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/135528/avatar/52549c9492fe7c04.jpg'/> </a>\n <div><a href=\"/profile/raylee\" title=\"Specialist raylee\" class=\"rated-user user-cyan\">raylee</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/02/2014 11:07\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159679\" href=\"?#comment-159679\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"159679\" revisionCount=\"13\" revision=\"13\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">13</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"159679\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"135528\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159679\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In the problem D, said "The complexity is: <span class=\"tex-span\"><i>O</i>(<i>n</i><sup class=\"upper-index\">2</sup> <i>m</i>)</span> time." But n and m (2 ≤ n ≤ 500, 1 ≤ m ≤ 1000). Can you explain why this complexity wont TLE? thank you.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159679 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159679 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159679\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159685\" commentParentId=\"159679\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/gridnevvvit\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/31163/avatar/db500a30a0b0a6f1.jpg'/> </a>\n <div><a href=\"/profile/gridnevvvit\" title=\"Candidate Master gridnevvvit\" class=\"rated-user user-violet\">gridnevvvit</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/02/2014 11:55\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159685\" href=\"?#comment-159685\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159679\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159685\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"31163\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159685\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Yes. First, let's calculate number of operations: it is about <span class=\"tex-span\">2 * 10<sup class=\"upper-index\">8</sup></span>. It is not so much. If you have good implementation of Kuhn, it would pass. Also, I know, that number of operation is much lower than <span class=\"tex-span\">2 * 10<sup class=\"upper-index\">8</sup></span>.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159685 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159685 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159685\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159689\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/1nikhil9\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/60595/avatar/64f85d0070290be7.jpg'/> </a>\n <div><a href=\"/profile/1nikhil9\" title=\"Candidate Master 1nikhil9\" class=\"rated-user user-violet\">1nikhil9</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/02/2014 14:07\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159689\" href=\"?#comment-159689\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159689\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"60595\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159689\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Test case 4 for Problem D says N = 153, M = 392. But there are only 391 edges in the input file.</p><p><a href=\"//codeforces.com/contest/387/submission/5868021\">http://codeforces.com/contest/387/submission/5868021</a></p><p>Am I misunderstanding something? Thanks.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159689 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159689 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159689\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159694\" commentParentId=\"159689\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/gridnevvvit\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/31163/avatar/db500a30a0b0a6f1.jpg'/> </a>\n <div><a href=\"/profile/gridnevvvit\" title=\"Candidate Master gridnevvvit\" class=\"rated-user user-violet\">gridnevvvit</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/02/2014 15:06\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159694\" href=\"?#comment-159694\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159689\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159694\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"31163\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159694\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Testcase is valid.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159694 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159694 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159694\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"160860\" commentParentId=\"159694\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/khrak\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/128936/avatar/6d9b38f723c23a83.jpg'/> </a>\n <div><a href=\"/profile/khrak\" title=\"Expert khrak\" class=\"rated-user user-blue\">khrak</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/07/2014 20:07\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-160860\" href=\"?#comment-160860\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159694\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"160860\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"128936\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-160860\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>What does n variable mean in C problem tutorial? </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-160860 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-160860 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-160860\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"160876\" commentParentId=\"160860\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/gridnevvvit\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/31163/avatar/db500a30a0b0a6f1.jpg'/> </a>\n <div><a href=\"/profile/gridnevvvit\" title=\"Candidate Master gridnevvvit\" class=\"rated-user user-violet\">gridnevvvit</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/08/2014 00:57\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-160876\" href=\"?#comment-160876\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-160860\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"160876\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"31163\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-160876\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>n is the length of the number from the input.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-160876 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-160876 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-160876\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"160894\" commentParentId=\"160876\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/khrak\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/128936/avatar/6d9b38f723c23a83.jpg'/> </a>\n <div><a href=\"/profile/khrak\" title=\"Expert khrak\" class=\"rated-user user-blue\">khrak</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/08/2014 11:15\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-160894\" href=\"?#comment-160894\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-160876\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"160894\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"128936\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-160894\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>So, for 800101 we have a1 = 800, a2 = 10, a3 = 1, and n = 6. what value has i for this example, 1 or -1? </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-160894 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-160894 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-160894\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"160913\" commentParentId=\"160894\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/gridnevvvit\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/31163/avatar/db500a30a0b0a6f1.jpg'/> </a>\n <div><a href=\"/profile/gridnevvvit\" title=\"Candidate Master gridnevvvit\" class=\"rated-user user-violet\">gridnevvvit</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/08/2014 14:34\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-160913\" href=\"?#comment-160913\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-160894\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"160913\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"31163\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-160913\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>i equals to -1. I understood, that there is an small mistake: answer is <span class=\"tex-span\"><i>k</i> - <i>i</i> + 1</span></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-160913 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-160913 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-160913\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"160924\" commentParentId=\"160913\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/khrak\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/128936/avatar/6d9b38f723c23a83.jpg'/> </a>\n <div><a href=\"/profile/khrak\" title=\"Expert khrak\" class=\"rated-user user-blue\">khrak</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/08/2014 16:02\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-160924\" href=\"?#comment-160924\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-160913\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"160924\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"128936\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-160924\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Sorry for so many questions, but I can't still understand how we count answer answer for 800101. here k equals 3, i equals -1 (as you said), then answer should be k — i + 1 = 3 — (-1) + 1 = 5 when answer here is 3.. What I didn't understand correctly? </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-160924 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-160924 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-160924\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"160928\" commentParentId=\"160924\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/gridnevvvit\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/31163/avatar/db500a30a0b0a6f1.jpg'/> </a>\n <div><a href=\"/profile/gridnevvvit\" title=\"Candidate Master gridnevvvit\" class=\"rated-user user-violet\">gridnevvvit</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/08/2014 17:23\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-160928\" href=\"?#comment-160928\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-160924\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"160928\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"31163\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-160928\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Oh, it's my mistake. If there is no such index, index i should be equals to 1, yes.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-160928 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-160928 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-160928\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"160929\" commentParentId=\"160928\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/khrak\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/128936/avatar/6d9b38f723c23a83.jpg'/> </a>\n <div><a href=\"/profile/khrak\" title=\"Expert khrak\" class=\"rated-user user-blue\">khrak</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/08/2014 17:27\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-160929\" href=\"?#comment-160929\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-160928\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"160929\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"128936\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-160929\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Okey. Then I understand and I'll think about proof. Thank you! :) </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-160929 en true\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-160929 en true\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-160929\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"161379\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/rohitjv\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/107177/avatar/3326d08f28613bd4.jpg'/> </a>\n <div><a href=\"/profile/rohitjv\" title=\"Expert rohitjv\" class=\"rated-user user-blue\">rohitjv</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/12/2014 21:33\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-161379\" href=\"?#comment-161379\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"161379\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"107177\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-161379\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In problem C, the definition of the array <em>need[i]</em> in the description does not match with the code provided. The actual definition of <em>need[i]</em> should be : need[i] — equals to <strong>0</strong> if we should remove number i from permutation p, and <strong>1</strong> if we shouldn't remove i from permutation p. Please correct me if I am wrong.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-161379 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-161379 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-161379\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"161380\" commentParentId=\"161379\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/gridnevvvit\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/31163/avatar/db500a30a0b0a6f1.jpg'/> </a>\n <div><a href=\"/profile/gridnevvvit\" title=\"Candidate Master gridnevvvit\" class=\"rated-user user-violet\">gridnevvvit</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/12/2014 21:56\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-161380\" href=\"?#comment-161380\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-161379\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"161380\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"31163\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-161380\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Yes, description does not match with the code provided. There are only ideas in editorial, so there are can be differences. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-161380 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-161380 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-161380\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"161811\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Nakochi\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/101746/avatar/ccfafe3f7587f95d.jpg'/> </a>\n <div><a href=\"/profile/Nakochi\" title=\"Expert Nakochi\" class=\"rated-user user-blue\">Nakochi</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/17/2014 18:23\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-161811\" href=\"?#comment-161811\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"161811\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"101746\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-161811\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Problem C is really a challenge for me!!! Orz!!!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-161811 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-161811 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-161811\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"161820\" commentParentId=\"161811\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Nodir.Daminov\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/71439/avatar/d6d2016f6dfe5ecd.jpg'/> </a>\n <div><a href=\"/profile/Nodir.Daminov\" title=\"Candidate Master Nodir.Daminov\" class=\"rated-user user-violet\">Nodir.Daminov</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/17/2014 19:19\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-161820\" href=\"?#comment-161820\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-161811\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"161820\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"71439\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-161820\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Who cares ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-161820 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-161820 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-161820\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"161902\" commentParentId=\"161820\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Nakochi\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/101746/avatar/ccfafe3f7587f95d.jpg'/> </a>\n <div><a href=\"/profile/Nakochi\" title=\"Expert Nakochi\" class=\"rated-user user-blue\">Nakochi</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/18/2014 18:14\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-161902\" href=\"?#comment-161902\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-161820\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"161902\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"101746\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-161902\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Sorry, I misunderstood the problem. Now it's much easier. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-161902 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-161902 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-161902\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"161903\" commentParentId=\"161902\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Nodir.Daminov\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/71439/avatar/d6d2016f6dfe5ecd.jpg'/> </a>\n <div><a href=\"/profile/Nodir.Daminov\" title=\"Candidate Master Nodir.Daminov\" class=\"rated-user user-violet\">Nodir.Daminov</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/18/2014 18:25\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-161903\" href=\"?#comment-161903\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-161902\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"161903\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"71439\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-161903\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Who cares ???</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-161903 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-161903 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-161903\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"161904\" commentParentId=\"161903\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Nakochi\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/101746/avatar/ccfafe3f7587f95d.jpg'/> </a>\n <div><a href=\"/profile/Nakochi\" title=\"Expert Nakochi\" class=\"rated-user user-blue\">Nakochi</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/18/2014 18:54\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-161904\" href=\"?#comment-161904\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-161903\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"161904\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"101746\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-161904\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Seems you care. :D</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-161904 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-161904 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-161904\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n <br/>\r\n\r\n<div id=\"editBox-10654\" style=\"width:50em;display:none;\">\r\n <div class=\"previewBody\" style=\"border: 1px solid #d4d4d4; margin-bottom: 0.5em; padding: 0.25em; display:none;\"> </div>\r\n <div style=\"width: 1px\"> </div>\r\n <div class=\"commentLocale\" style=\"position: relative; top: 0.5em;left:4px;display: none;\">\r\n <input type=\"radio\" name=\"locale\" value=\"en\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In English</span>\r\n <input style=\"margin-left:1em\" type=\"radio\" name=\"locale\" value=\"ru\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In Russian</span>\r\n </div>\r\n <textarea data-drafts-id=\"CommentReplyFrame\" class=\"wysiwyg\" name=\"editContent\" rows=\"20\" style=\"width:99%;\"></textarea>\r\n <div class=\"error error__content\"></div>\r\n <div style=\"text-align:center;\">\r\n <input type=\"button\" name=\"preview\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Preview\"/>\r\n <input type=\"button\" name=\"save\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Save\"/>\r\n </div>\r\n</div>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n\r\nvar firstPreview10654 = true;\r\nvar lastPreviewContent10654 = '';\r\n\r\nif (!window.moveCommentRevision) {\r\n moveCommentRevision = function(e, dir) {\r\n var p = e.parent();\r\n var revisionCount = parseInt(p.attr(\"revisionCount\"));\r\n var revision = parseInt(p.attr(\"revision\"));\r\n var next = revision + dir;\r\n var commentId = p.attr(\"commentId\");\r\n if (next >= 1 && next <= revisionCount) {\r\n $.post(\r\n \"/data/comment-data\",\r\n {action: \"revision\", commentId: commentId, revision: next},\r\n function(json) {\r\n if (json.success == \"true\") {\r\n var parentDiv = e;\r\n\r\n while (parentDiv !== null && (parentDiv[0].nodeName.toLowerCase() !== \"td\" || !parentDiv.hasClass(\"right\"))) {\r\n parentDiv = parentDiv.parent();\r\n }\r\n\r\n if (parentDiv === null) {\r\n return;\r\n }\r\n\r\n parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\").html(json.content);\r\n Codeforces.setupSpoilers(parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\"));\r\n p.attr(\"revision\", next);\r\n p.find(\"span.revision\").text(next);\r\n if (next == 1) {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"visible\");\r\n }\r\n if (next == revisionCount) {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"visible\");\r\n }\r\n\r\n window.updateTypography();\r\n MathJax.Hub.Typeset();\r\n } else {\r\n alert(e.error);\r\n }\r\n },\r\n \"json\"\r\n );\r\n }\r\n };\r\n}\r\n\r\n$(\"div[commentableId=10654] a.leftRevision\").click(function () {\r\n window.moveCommentRevision($(this), -1);\r\n return false;\r\n});\r\n\r\n$(\"div[commentableId=10654] a.rightRevision\").click(function () {\r\n window.moveCommentRevision($(this), +1);\r\n return false;\r\n});\r\n\r\n\r\n\r\n });\n </script>\n\r\n\r\n <script src=\"//codeforces.org/s/81027/js/swfobject-2.2.min.js\" type=\"text/javascript\"></script>\n <script src=\"//codeforces.org/s/81027/js/ftaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n if (window.evercookie) {\n var ec = new evercookie({\n history: false,\n silverlight: false,\n baseurl: '',\n asseturi: '/assets',\n phpuri: '/2fdcd78',\n pngPath: '/eps',\n etagPath: '/ees',\n cachePath: '/ecs'\n });\n\n var randomNumber = function () {\n return Math.random().toString(36).substr(2);\n };\n\n var randomToken = function () {\n return (randomNumber() + randomNumber()).substring(0, 18);\n };\n\n window._ftaa = \"\";\n\n ec.get(\"70a7c28f3de\", function (value) {\n window._ftaa = value;\n if (!window._ftaa) {\n window._ftaa = randomToken();\n ec.set(\"70a7c28f3de\", window._ftaa);\n }\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n } else {\n window._ftaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\n <script src=\"//codeforces.org/s/81027/js/bfaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n var fpCallback = function() {\n Fingerprint2.get({}, function(components) {\n window._bfaa = Fingerprint2.x64hash128(components.map(function (pair) { return pair.value }).join(), 31);\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n };\n if (typeof Fingerprint2 !== 'undefined') {\n if (window.requestIdleCallback) {\n requestIdleCallback(fpCallback)\n } else {\n setTimeout(fpCallback, 500)\n }\n } else {\n window._bfaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"a.new-root-comment\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n\r\n $(\".comment-table .reply a\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".vote-for-comment\").mouseover(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").mouseout(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").click(function () {\r\n var vote = $(this);\r\n var commentId = $(this).parent().attr(\"commentid\");\r\n var commentRating = $(this).parent().attr(\"data-commentRating\");\r\n var direction = $(this).attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n $.post(\"/data/comment/vote\", {commentId: commentId, _tta: Codeforces.tta(), vote: direction, commentRating: commentRating}, function(data) {\r\n if (direction != 0 && !ownComment && data[\"success\"] == \"true\") {\r\n vote.parent().find(\".vote-for-comment\").attr(\"voteDirection\", 0);\r\n if (direction == 1)\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n else {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.closest(\".CommentVoteFrame\").find(\".ComplaintFrame\").css(\"display\", \"inline-block\");\r\n }\r\n vote.find(\"img\").attr(\"popacity\", \"1.0\");\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n vote.parent().find(\".commentRating\").html(data[\"commentRating\"]);\r\n }\r\n Codeforces.showMessage(data[\"message\"]);\r\n }, \"json\");\r\n return false;\r\n });\r\n\r\n $(\".negative-comment-vote\").closest(\".comment-table\").addClass(\"comment-bad\");\r\n\r\n $(\".troll-comment-vote\").closest(\".comment\").css(\"display\", \"none\");\r\n\r\n $(\".too-negative-comment-vote\").closest(\".comment-table\").each(function () {\r\n var e = $(this);\r\n e.addClass(\"comment-too-bad\");\r\n var commentId = e.attr(\"commentId\");\r\n $(\"<div class='bad-comment-replacement ttypography'>The comment is hidden because of too negative feedback, click <a href=# class=show-bad-comment-link>here</a> to view it</div>\").appendTo(\r\n e.find(\".right\")\r\n );\r\n e.find(\".comment-content\").hide();\r\n e.find(\".show-bad-comment-link\").click(function () {\r\n e.find(\".comment-content\").show();\r\n e.find(\".bad-comment-replacement\").hide();\r\n return false;\r\n });\r\n });\r\n });\n </script>\n </div>\r\n\r\n <style type=\"text/css\">\r\n .new-comments-box {\r\n padding: 0.5em;\r\n width: 22px;\r\n font-size: 1.3rem;\r\n font-weight: bold !important;\r\n\r\n position: fixed;\r\n top: 40%;\r\n right: 0;\r\n opacity: 0.2;\r\n color: white;\r\n text-align: center;\r\n\r\n border: 1px solid #222;\r\n background-color: #888 !important;\r\n border-radius: 3px;\r\n -moz-border-radius: 3px;\r\n -webkit-border-radius: 3px;\r\n }\r\n\r\n .new-comments-box:hover {\r\n opacity: 1;\r\n }\r\n\r\n .new-comments-box .dir:hover {\r\n background: #3B5998 !important;\r\n cursor: pointer;\r\n }\r\n </style>\r\n\r\n <div class=\"new-comments-box\" data-position=\"outside\" data-index=\"-1\" style=\"display: none;\">\r\n <div class=\"up dir\" title=\"Ctrl+Up\">↑<hr/>\r\n </div>\r\n <div class=\"info\" title=\"New comments\"></div>\r\n <div class=\"down dir\" title=\"Ctrl+Down\">\r\n <hr/>↓\r\n </div>\r\n </div>\r\n\r\n <script>\r\n $(\".show-archived-checkbox\").change(function () {\r\n const checked = $(this).is(\":checked\");\r\n $.post(\"/data/comment-data\", {action: \"setShowArchived\", checked}, function (json) {\r\n if (json[\"success\"] !== \"true\") {\r\n alert(json[\"error\"]);\r\n } else {\r\n if (checked) {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are now displayed\")\r\n } else {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are no longer displayed\")\r\n }\r\n }\r\n });\r\n return false;\r\n });\r\n\r\n function gotoComment(direction) {\r\n var box = $(\".new-comments-box\");\r\n var index = parseInt(box.attr(\"data-index\"));\r\n if (index == -1)\r\n index = 0;\r\n else\r\n index = Math.max(0, Math.min(parseInt(box.find(\".info\").text()) - 1, index + direction));\r\n box.attr(\"data-index\", index);\r\n var comment = $($(\".comment .highlight-blue[commentId]\").get(index));\r\n $('html, body').animate({\r\n 'scrollTop': Math.max(0, comment.offset().top - ($(window).height() - comment.height()) / 2)\r\n });\r\n return false;\r\n }\r\n\r\n $(\".new-comments-box .down\").click(function () {\r\n return gotoComment(1);\r\n });\r\n\r\n $(\".new-comments-box .up\").click(function () {\r\n return gotoComment(-1);\r\n });\r\n\r\n $(document).keydown(function (e) {\r\n var code = (e.keyCode ? e.keyCode : e.which);\r\n if (e.ctrlKey) {\r\n if (code == 38 || code == 40) {\r\n gotoComment(code - 39);\r\n }\r\n }\r\n });\r\n\r\n var newCommentCount = $(\".comment .highlight-blue[commentId]\").length;\r\n if (newCommentCount > 0) {\r\n $(\".new-comments-box .info\").text(newCommentCount);\r\n $(\".new-comments-box\").show();\r\n }\r\n\r\n $('table.comment-table').mouseenter(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").addClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n\r\n $('table.comment-table').mouseleave(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").removeClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n </script>\r\n\r\n\r\n\r\n <script>\r\n function adjustTopicComplainFrames() {\r\n let topicIds = [];\r\n\r\n $(\".has-topic-id\").each(function () {\r\n const $this = $(this);\r\n const topicId = $this.attr(\"topicId\");\r\n if (topicId) {\r\n topicIds.push(topicId);\r\n }\r\n });\r\n\r\n $.post(\"/data/topics\", {\r\n action: \"findComplainableTopicIds\",\r\n topicIds: topicIds.join(\",\")\r\n }, function (json) {\r\n if (json[\"success\"] === \"true\") {\r\n for (const topicId of json[\"complainableTopicIds\"].split(\",\")) {\r\n $(\".has-topic-id[topicId=\" + topicId + \"]\").each(function () {\r\n $(this).find(\".meta .ComplaintFrame\").css(\"display\", \"inline-block\");\r\n });\r\n }\r\n }\r\n }, \"json\");\r\n }\r\n\r\n $(function () {\r\n adjustTopicComplainFrames();\r\n })\r\n </script>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-10638\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 10638, _tta: Codeforces.tta(), topicRevisionId: 37197, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-10638\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 10638, _tta: Codeforces.tta(), topicRevisionId: 37197, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n </div>\r\n </div>\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 22:13:05</span> (h1).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/81027/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/81027/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/81027/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/81027/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-81027.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'812875999be52de2',t:'MTY5NjcwNTk4NS43NTIwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"}}},{"rowIdx":1956,"cells":{"problem_id":{"kind":"string","value":"387D"},"contest":{"kind":"string","value":"387"},"problem":{"kind":"string","value":"D"},"lang":{"kind":"string","value":"en"},"problem_title":{"kind":"string","value":"D. George and Interesting Graph"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">D. George and Interesting Graph</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>George loves graphs. Most of all, he loves interesting graphs. We will assume that a directed graph is <span class=\"tex-font-style-it\">interesting</span>, if it meets the following criteria: </p><ul> <li> The graph doesn't contain any multiple arcs; </li><li> There is vertex <span class=\"tex-span\"><i>v</i></span> (we'll call her the <span class=\"tex-font-style-it\">center</span>), such that for any vertex of graph <span class=\"tex-span\"><i>u</i></span>, the graph contains arcs <span class=\"tex-span\">(<i>u</i>, <i>v</i>)</span> and <span class=\"tex-span\">(<i>v</i>, <i>u</i>)</span>. Please note that the graph also contains loop <span class=\"tex-span\">(<i>v</i>, <i>v</i>)</span>. </li><li> The outdegree of all vertexes except for the <span class=\"tex-font-style-it\">center</span> equals two and the indegree of all vertexes except for the <span class=\"tex-font-style-it\">center</span> equals two. The outdegree of vertex <span class=\"tex-span\"><i>u</i></span> is the number of arcs that go out of <span class=\"tex-span\"><i>u</i></span>, the indegree of vertex <span class=\"tex-span\"><i>u</i></span> is the number of arcs that go in <span class=\"tex-span\"><i>u</i></span>. Please note that the graph can contain loops. </li></ul><p>However, not everything's that simple. George got a directed graph of <span class=\"tex-span\"><i>n</i></span> vertices and <span class=\"tex-span\"><i>m</i></span> arcs as a present. The graph didn't have any multiple arcs. As George loves interesting graphs, he wants to slightly alter the presented graph and transform it into an interesting one. In one alteration he can either remove an arbitrary existing arc from the graph or add an arbitrary arc to the graph. </p><p>George wonders: what is the minimum number of changes that he needs to obtain an interesting graph from the graph he's got as a present? Help George and find the answer to the question.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains two space-separated integers <span class=\"tex-span\"><i>n</i></span> and <span class=\"tex-span\"><i>m</i></span> (<span class=\"tex-span\">2 ≤ <i>n</i> ≤ 500, 1 ≤ <i>m</i> ≤ 1000</span>) — the number of vertices and arcs in the presented graph.</p><p>Each of the next <span class=\"tex-span\"><i>m</i></span> lines contains two space-separated integers <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub>, <i>b</i><sub class=\"lower-index\"><i>i</i></sub></span> (<span class=\"tex-span\">1 ≤ <i>a</i><sub class=\"lower-index\"><i>i</i></sub>, <i>b</i><sub class=\"lower-index\"><i>i</i></sub> ≤ <i>n</i></span>) — the descriptions of the graph's arcs. Pair <span class=\"tex-span\">(<i>a</i><sub class=\"lower-index\"><i>i</i></sub>, <i>b</i><sub class=\"lower-index\"><i>i</i></sub>)</span> means that the graph contains an arc from vertex number <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> to vertex number <span class=\"tex-span\"><i>b</i><sub class=\"lower-index\"><i>i</i></sub></span>. It is guaranteed that the presented graph doesn't contain multiple arcs.</p><p>Assume that the grah vertices are numbered 1 through <span class=\"tex-span\"><i>n</i></span>.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print a single integer — the answer to George's question.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>3 7<br/>1 1<br/>2 2<br/>3 1<br/>1 3<br/>3 2<br/>2 3<br/>3 3<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>0<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3 6<br/>1 1<br/>2 2<br/>3 1<br/>3 2<br/>2 3<br/>3 3<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3 1<br/>2 2<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>6<br/></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>For more information about directed graphs, please visit: <span class=\"tex-font-style-tt\">http://en.wikipedia.org/wiki/Directed_graph</span></p><p>In the first sample the graph already is interesting, its center is vertex <span class=\"tex-span\">3</span>.</p></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"823544cc07b0f0302919a769b0f8f2e2\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - D - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"1d8414af0a90e113b8a49898336bf2bc6a1719bc\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - D - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/73366/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/73366/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/73366/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/73366/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/73366/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/73366/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/73366/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/73366/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/73366/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/73366/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/73366/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/73366/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/73366/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/73366/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/sidebar-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/a037fe51637846d9c7c725713cd840ea/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='823544cc07b0f0302919a769b0f8f2e2'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/73366/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/73366/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fcontest%2F387%2Fproblem%2FD%3Flocale%3Den\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"current\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='823544cc07b0f0302919a769b0f8f2e2'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:100%;\"><a style=\"color: black\" href=\"/contest/387\">Codeforces Round 227 (Div. 2)</a></th>\n </tr>\n <tr>\n <td class=\"left bottom\" colspan=\"1\"><span class=\"contest-state-phase\">Finished</span></td>\n </tr>\n </tbody>\n </table>\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Practice?\n <div class=\"top-links\">\n </div>\n </div>\n<div>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Want to solve the contest problems after the official contest ends? Just register for practice and you will be able to submit solutions.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"\" method=\"post\"><input type='hidden' name='csrf_token' value='823544cc07b0f0302919a769b0f8f2e2'/>\r\n <input type=\"hidden\" name=\"action\" value=\"registerForPractice\"/>\r\n <input type=\"submit\" name=\"submit\" value=\"Register for practice\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div> \r\n</div>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox ContestVirtualFrame borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Virtual participation <i class=\"sidebar-caption-icon las la-angle-down\"></i>\r\n\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\" \"\r\n\r\n data-page-url=\"/data/sidebarFrames\"\r\n\r\n>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests.\n\nIf you've seen these problems, a virtual contest is not for you - solve these problems in the archive.\n\nIf you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.\n\nNever use someone else's code, read the tutorials or communicate with other person during a virtual contest.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"/contest/387/virtual\" method=\"get\">\r\n <input type=\"submit\" name=\"submit\" value=\"Start virtual contest\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div>\r\n</div>\r\n <script>\r\n $(function () {\r\n $(\".ContestVirtualFrame .sidebar-caption-icon\").click(function() {\r\n $(this).toggleClass(\"la-angle-down la-angle-right\");\r\n const $target = $(this).parent().next();\r\n $target.toggle();\r\n const dataPageUrl = $target.attr(\"data-page-url\");\r\n const collapsed = $(this).hasClass(\"la-angle-right\");\r\n const params = {\r\n action: \"setCollapsed\",\r\n sidebarFrameSimpleClassName: \"ContestVirtualFrame\",\r\n collapsed\r\n };\r\n $.each($target[0].attributes, function(i, a) {\r\n const name = a.name;\r\n if (name.startsWith(\"data-extra-key-\")) {\r\n const key = a.value;\r\n const keyIndex = parseInt(name.substring(\"data-extra-key-\".length));\r\n const value = $target.attr(\"data-extra-value-\" + keyIndex);\r\n params[key] = value;\r\n }\r\n });\r\n $.post(dataPageUrl, params, function (result) {\r\n if (result[\"success\"] !== \"true\") {\r\n Codeforces.showMessage(\"Failed to save collapsed state.\");\r\n }\r\n }, \"json\");\r\n return false;\r\n });\r\n })\r\n </script>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Problem tags\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Graph matchings, König's theorem, vertex cover of bipartite graph\">\r\n graph matchings\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Difficulty\">\r\n *2200\r\n</span>\r\n </div>\n <div style=\"clear:both;text-align:right;font-size:1.1rem;\">\r\n <span title=\"Please login into the Codeforces\" class=\"notice\">No tag edit access</span>\r\n </div>\r\n</div>\r\n </div>\n\r\n<form id=\"addTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='823544cc07b0f0302919a769b0f8f2e2'/>\r\n <input name=\"action\" type=\"hidden\" value=\"addTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"6209\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<form id=\"removeTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='823544cc07b0f0302919a769b0f8f2e2'/>\r\n <input name=\"action\" type=\"hidden\" value=\"removeTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"6209\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<script type=\"text/javascript\">\r\n $(\".tag-box img\").click(function () {\r\n var tagName = $(this).attr(\"value\");\r\n Codeforces.confirm(\"Are you sure you want to remove this tag?\", function () {\r\n $(\"#removeTagForm input[name=tagName]\").val(tagName);\r\n $(\"#removeTagForm\").submit();\r\n }, function () {\r\n }, \"Yes\", \"No\");\r\n });\r\n\r\n $(\"#addTagLink\").click(function () {\r\n $(this).hide();\r\n $(\"#addTagLabel\").show();\r\n return false;\r\n });\r\n\r\n $(\"#addTagSelect\").change(function () {\r\n var tagName = $(this).val();\r\n if (tagName === \"\") {\r\n $(\"#addTagLabel\").hide();\r\n $(\"#addTagLink\").show();\r\n } else {\r\n $(\"#addTagForm input[name=tagName]\").val(tagName);\r\n $(\"#addTagForm\").submit();\r\n }\r\n });\r\n</script>\r\n\r\n<style type=\"text/css\">\r\n#new-resource-form tr td {\r\npadding-top: 0.5em;\r\n}\r\n#new-resource-form input:not([type=\"submit\"]) {\r\nfont-size: 0.8em;\r\n}\r\n#new-resource-form select {\r\nfont-size: 0.8em;\r\n}\r\n.new-resource-error {\r\nfont-size: 0.8em;\r\n}\r\n.resource-locale {\r\ncolor: #666;\r\nfont-family: Consolas, \"Andale Mono WT\", \"Andale Mono\", \"Lucida Console\", \"Lucida Sans Typewriter\", \"DejaVu Sans Mono\", \"Bitstream Vera Sans Mono\", \"Liberation Mono\", \"Nimbus Mono L\", Monaco, \"Courier New\", Courier, monospace;\r\n}\r\n</style>\r\n<div class=\"roundbox sidebox sidebar-menu borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Contest materials\n<div class=\"top-links\">\n</div>\n</div>\n<ul>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/10569\" title=\"Codeforces Round #227 (Div. 2)\" target=\"_blank\">Announcement</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"2176:2182\" resourceName=\"Announcement\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/10583\" title=\"Editorial Codeforces Round #227 (Div. 2)\" target=\"_blank\">Tutorial</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"2177:2183\" resourceName=\"Tutorial\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n</ul>\r\n</div></div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li class=\"current selectedLava\"><a\r\n href=\"/contest/387\">Problems</a></li>\r\n <li><a\r\n href=\"/contest/387/submit\">Submit Code</a></li>\r\n <li><a\r\n href=\"/contest/387/my\">My Submissions</a></li>\r\n <li><a\r\n href=\"/contest/387/status\">Status</a></li>\r\n <li><a\r\n href=\"/contest/387/hacks\">Hacks</a></li>\r\n <li><a\r\n href=\"/contest/387/room/1\">Room</a></li>\r\n <li><a\r\n href=\"/contest/387/standings\">Standings</a></li>\r\n <li><a\r\n href=\"/contest/387/customtest\">Custom Invocation</a></li>\r\n</ul>\r\n</div>\n\r\n <style>\r\n #facebox .content:has(.diff-popup) {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n }\r\n\r\n .testCaseMarker {\r\n position: absolute;\r\n font-weight: bold;\r\n font-size: 1rem;\r\n }\r\n\r\n .diff-popup {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n display: none;\r\n overflow: auto;\r\n }\r\n\r\n .input-output-copier {\r\n font-size: 1.2rem;\r\n float: right;\r\n color: #888 !important;\r\n cursor: pointer;\r\n border: 1px solid rgb(185, 185, 185);\r\n padding: 3px;\r\n margin: 1px;\r\n line-height: 1.1rem;\r\n text-transform: none;\r\n }\r\n\r\n .input-output-copier:hover {\r\n background-color: #def;\r\n }\r\n\r\n .test-explanation textarea {\r\n width: 100%;\r\n height: 1.5em;\r\n }\r\n\r\n .pending-submission-message {\r\n color: darkorange !important;\r\n }\r\n </style>\r\n <script>\r\n const OPENING_SPACE = String.fromCharCode(1001);\r\n const CLOSING_SPACE = String.fromCharCode(1002);\r\n\r\n const nodeToText = function (node, pre) {\r\n let result = [];\r\n\r\n if (node.tagName === \"SCRIPT\" || node.tagName === \"math\"\r\n || (node.classList && node.classList.contains(\"input-output-copier\")))\r\n return [];\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(OPENING_SPACE);\r\n }\r\n\r\n if (node.nodeType === Node.TEXT_NODE) {\r\n let s = node.textContent;\r\n if (!pre) {\r\n s = s.replace(/\\s+/g, \" \");\r\n }\r\n if (s.length > 0) {\r\n result.push(s);\r\n }\r\n }\r\n\r\n if (pre && node.tagName === \"BR\") {\r\n result.push(\"\\n\");\r\n }\r\n\r\n node.childNodes.forEach(function (child) {\r\n result.push(nodeToText(child, node.tagName === \"PRE\").join(\"\"));\r\n });\r\n\r\n if (node.tagName === \"DIV\"\r\n || node.tagName === \"P\"\r\n || node.tagName === \"PRE\"\r\n || node.tagName === \"UL\"\r\n || node.tagName === \"LI\"\r\n ) {\r\n result.push(\"\\n\");\r\n }\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(CLOSING_SPACE);\r\n }\r\n\r\n return result;\r\n }\r\n\r\n const isSpecial = function (c) {\r\n return c === ',' || c === '.' || c === ';' || c === ')' || c === ' ';\r\n }\r\n\r\n const convertStatementToText = function(statmentNode) {\r\n const text = nodeToText(statmentNode, false).join(\"\").replace(/ +/g, \" \").replace(/\\n\\n+/g, \"\\n\\n\");\r\n let result = [];\r\n for (let i = 0; i < text.length; i++) {\r\n const c = text.charAt(i);\r\n if (c === OPENING_SPACE) {\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"D\" data-uuid=\"ps_7ee36983c1f97e25f485bc5d6f9d688312fe5448\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">D. George and Interesting Graph</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>George loves graphs. Most of all, he loves interesting graphs. We will assume that a directed graph is <span class=\"tex-font-style-it\">interesting</span>, if it meets the following criteria: </p><ul> <li> The graph doesn't contain any multiple arcs; </li><li> There is vertex <span class=\"tex-span\"><i>v</i></span> (we'll call her the <span class=\"tex-font-style-it\">center</span>), such that for any vertex of graph <span class=\"tex-span\"><i>u</i></span>, the graph contains arcs <span class=\"tex-span\">(<i>u</i>, <i>v</i>)</span> and <span class=\"tex-span\">(<i>v</i>, <i>u</i>)</span>. Please note that the graph also contains loop <span class=\"tex-span\">(<i>v</i>, <i>v</i>)</span>. </li><li> The outdegree of all vertexes except for the <span class=\"tex-font-style-it\">center</span> equals two and the indegree of all vertexes except for the <span class=\"tex-font-style-it\">center</span> equals two. The outdegree of vertex <span class=\"tex-span\"><i>u</i></span> is the number of arcs that go out of <span class=\"tex-span\"><i>u</i></span>, the indegree of vertex <span class=\"tex-span\"><i>u</i></span> is the number of arcs that go in <span class=\"tex-span\"><i>u</i></span>. Please note that the graph can contain loops. </li></ul><p>However, not everything's that simple. George got a directed graph of <span class=\"tex-span\"><i>n</i></span> vertices and <span class=\"tex-span\"><i>m</i></span> arcs as a present. The graph didn't have any multiple arcs. As George loves interesting graphs, he wants to slightly alter the presented graph and transform it into an interesting one. In one alteration he can either remove an arbitrary existing arc from the graph or add an arbitrary arc to the graph. </p><p>George wonders: what is the minimum number of changes that he needs to obtain an interesting graph from the graph he's got as a present? Help George and find the answer to the question.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains two space-separated integers <span class=\"tex-span\"><i>n</i></span> and <span class=\"tex-span\"><i>m</i></span> (<span class=\"tex-span\">2 ≤ <i>n</i> ≤ 500, 1 ≤ <i>m</i> ≤ 1000</span>) — the number of vertices and arcs in the presented graph.</p><p>Each of the next <span class=\"tex-span\"><i>m</i></span> lines contains two space-separated integers <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub>, <i>b</i><sub class=\"lower-index\"><i>i</i></sub></span> (<span class=\"tex-span\">1 ≤ <i>a</i><sub class=\"lower-index\"><i>i</i></sub>, <i>b</i><sub class=\"lower-index\"><i>i</i></sub> ≤ <i>n</i></span>) — the descriptions of the graph's arcs. Pair <span class=\"tex-span\">(<i>a</i><sub class=\"lower-index\"><i>i</i></sub>, <i>b</i><sub class=\"lower-index\"><i>i</i></sub>)</span> means that the graph contains an arc from vertex number <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> to vertex number <span class=\"tex-span\"><i>b</i><sub class=\"lower-index\"><i>i</i></sub></span>. It is guaranteed that the presented graph doesn't contain multiple arcs.</p><p>Assume that the grah vertices are numbered 1 through <span class=\"tex-span\"><i>n</i></span>.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print a single integer — the answer to George's question.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>3 7<br />1 1<br />2 2<br />3 1<br />1 3<br />3 2<br />2 3<br />3 3<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>0<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3 6<br />1 1<br />2 2<br />3 1<br />3 2<br />2 3<br />3 3<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3 1<br />2 2<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>6<br /></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>For more information about directed graphs, please visit: <span class=\"tex-font-style-tt\">http://en.wikipedia.org/wiki/Directed_graph</span></p><p>In the first sample the graph already is interesting, its center is vertex <span class=\"tex-span\">3</span>.</p></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=D]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== statementText) {\r\n $problem.find(\".diff-notifier\").show();\r\n\r\n $problem.find(\".diff-notifier-close\").click(function() {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n $problem.find(\".diff-notifier\").hide();\r\n });\r\n\r\n $problem.find(\"a.view-changes\").click(function() {\r\n $.post(\"/data/diff\", {action: \"getDiff\", a: previousStatementText, b: statementText}, function (result) {\r\n if (result[\"success\"] === \"true\") {\r\n Codeforces.facebox(\".diff-popup\", \"//codeforces.org/s/73366\");\r\n $(\"#facebox .diff-popup\").html(result[\"diff\"]);\r\n }\r\n }, \"json\");\r\n });\r\n }\r\n } else {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n }\r\n });\r\n });\r\n </script>\r\n\r\n\r\n<script type=\"text/javascript\">\r\n $(document).ready(function () {\r\n window.changedTests = new Set();\r\n\r\n function endsWith(string, suffix) {\r\n return string.indexOf(suffix, string.length - suffix.length) !== -1;\r\n }\r\n\r\n const inputFileDiv = $(\"div.input-file\");\r\n const inputFile = inputFileDiv.text();\r\n const outputFileDiv = $(\"div.output-file\");\r\n const outputFile = outputFileDiv.text();\r\n\r\n\r\n if (!endsWith(inputFile, \"standard input\")\r\n && !endsWith(inputFile, \"standard input\")) {\r\n inputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n if (!endsWith(outputFile, \"standard output\")\r\n && !endsWith(outputFile, \"standard output\")) {\r\n outputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n const titleDiv = $(\"div.header div.title\");\r\n\r\n\r\n\r\n String.prototype.replaceAll = function (search, replace) {\r\n return this.split(search).join(replace);\r\n };\r\n\r\n $(\".sample-test .title\").each(function () {\r\n const preId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n const cpyId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n\r\n $(this).parent().find(\"pre\").attr(\"id\", preId);\r\n const $copy = $(\"<div title='Copy' data-clipboard-target='#\" + preId + \"' id='\" + cpyId + \"' class='input-output-copier'>Copy</div>\");\r\n $(this).append($copy);\r\n\r\n const clipboard = new Clipboard('#' + cpyId, {\r\n text: function (trigger) {\r\n const pre = document.querySelector('#' + preId);\r\n const lines = pre.querySelectorAll(\".test-example-line\");\r\n return Codeforces.filterClipboardText(pre.innerText, lines.length);\r\n }\r\n });\r\n\r\n const isInput = $(this).parent().hasClass(\"input\");\r\n\r\n clipboard.on('success', function (e) {\r\n if (isInput) {\r\n Codeforces.showMessage(\"The example input has been copied into the clipboard\");\r\n } else {\r\n Codeforces.showMessage(\"The example output has been copied into the clipboard\");\r\n }\r\n e.clearSelection();\r\n });\r\n });\r\n\r\n $(\".test-form-item input\").change(function () {\r\n addPendingSubmissionMessage($($(this).closest(\"form\")), \"You changed the answer, do not forget to submit it if you want to save the changes\");\r\n const index = $(this).closest(\".problemindexholder\").attr(\"problemindex\");\r\n let test = \"\";\r\n $(this).closest(\"form input\").each(function () {\r\n const test_ = $(this).attr(\"name\");\r\n if (test_ && test_.substring(0, 4) === \"test\") {\r\n test = test_;\r\n }\r\n });\r\n if (index.length > 0 && test.length > 0) {\r\n const indexTest = index + \"::\" + test;\r\n window.changedTests.add(indexTest);\r\n }\r\n });\r\n\r\n $(window).on('beforeunload', function () {\r\n if (window.changedTests.size > 0) {\r\n return 'Dialog text here';\r\n }\r\n });\r\n\r\n autosize($('.test-explanation textarea'));\r\n\r\n $(\".test-example-line\").hover(function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n let top = 1E20;\r\n let left = 1E20;\r\n let problem = $(this).closest(\".problemindexholder\");\r\n $(this).closest(\".input\").find(\".\" + clazz).css(\"background-color\", \"#FFFDE7\").each(function() {\r\n top = Math.min(top, $(this).offset().top);\r\n left = Math.min(left, $(this).offset().left);\r\n });\r\n let testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n if (testCaseMarker.length === 0) {\r\n const html = \"<div class=\\\"testCaseMarker testCaseMarker_\" + end + \" notice\\\"></div>\";\r\n problem.append($(html));\r\n testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n }\r\n if (testCaseMarker) {\r\n testCaseMarker.show()\r\n .offset({top, left: left - 20})\r\n .text(end);\r\n }\r\n }\r\n }\r\n });\r\n }, function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n $(\".\" + clazz).css(\"background-color\", \"\");\r\n $(this).closest(\".problemindexholder\").find(\".testCaseMarker_\" + end).hide();\r\n }\r\n }\r\n });\r\n });\r\n\r\n });\r\n</script>\r\n\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 05:38:26</span> (j3).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/73366/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/73366/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/73366/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/73366/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-73366.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'8122c498ae501411',t:'MTY5NjY0NjMwNi43NDEwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"},"long_tags":{"kind":"string","value":"[\"Graph matchings, K\\u00f6nig's theorem, vertex cover of bipartite graph\"]"},"short_tags":{"kind":"string","value":"[\"graph matchings\", \"*2200\"]"},"tutorial_link":{"kind":"string","value":"https://codeforces.com/blog/entry/10583"},"tutorial_page":{"kind":"string","value":"\r\n\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"36a5cb4572cb122db333ec3b9f88364a\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"h1\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Editorial Codeforces Round #227 (Div. 2) - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n \n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Editorial Codeforces Round #227 (Div. 2) - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/81027/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/81027/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/81027/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/81027/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/81027/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/81027/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/81027/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/81027/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/81027/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/81027/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/81027/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/81027/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/81027/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/81027/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/573cedc6b04c15481941f418269f4057/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='36a5cb4572cb122db333ec3b9f88364a'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/81027/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fblog%2Fentry%2F10583\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='36a5cb4572cb122db333ec3b9f88364a'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Pay attention\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n <div style=\"text-align:center;border-bottom: 1px solid rgb(185, 185, 185);margin:0 -0.5em 0.5em -0.5em;padding: 0 1em 0.5em 1em;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 1, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:51:56</span><br/><a href=\"/contestRegistration/1876\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n <div style=\"text-align:center;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 2, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:51:56</span><br/><a href=\"/contestRegistration/1877\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n\r\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div>\r\n\r\n\n <div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\n\r\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='36a5cb4572cb122db333ec3b9f88364a'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n </label>\r\n </div>\r\n <div style=\"padding: 0 1em 1em 1em;text-align:right;\">\r\n <input style=\"height:1.65em;padding:0 0.75em;\" type=\"submit\" value=\"Find\"/>\r\n </div>\r\n </form>\r\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".handleBox\").autocomplete(\"/data/handles\", {\r\n delay: 200,\r\n width: 200,\r\n selectFirst: false,\r\n matchContains: true,\r\n minChars: 3\r\n });\r\n $(\".handleForm\").attr(\"autocomplete\", \"off\").submit(function () {\r\n var link = \"/profile/userHandle\".replace(\r\n \"userHandle\", $(this).find(\".handleBox\").val()\r\n );\r\n window.location = link;\r\n return false;\r\n });\r\n });\n </script>\n\r\n\r\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Recent actions\n <div class=\"top-links\">\n </div>\n </div>\n <div class=\"recent-actions\">\r\n <ul>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/121073\">Meta Hacker Cup 2023 Round 1</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/.Danet\" title=\"Expert .Danet\" class=\"rated-user user-blue\">.Danet</a> →\r\n <a href=\"/blog/entry/121172\">[TLE on pretest1]</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\" class=\"rated-user user-red\">Pyqe</a> →\r\n <a href=\"/blog/entry/121025\">Codeforces Round #902 (Div. 1, Div. 2, based on COMPFEST 15 — Final Round)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pranshu_Pandya\" title=\"Specialist Pranshu_Pandya\" class=\"rated-user user-cyan\">Pranshu_Pandya</a> →\r\n <a href=\"/blog/entry/121171\">An Interesting Tree Problem</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/sszcdjr\" title=\"Master sszcdjr\" class=\"rated-user user-orange\">sszcdjr</a> →\r\n <a href=\"/blog/entry/119859\">Codeforces Round 896 (Div. 1, Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/119880\">It's Happening! Meta Hacker Cup 2023 Schedule</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/DaviddeGea1\" title=\"Expert DaviddeGea1\" class=\"rated-user user-blue\">DaviddeGea1</a> →\r\n <a href=\"/blog/entry/70917\">Number of ways of dividing an array into 2 parts such that sum of each part is > k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bekh\" title=\"Master Bekh\" class=\"rated-user user-orange\">Bekh</a> →\r\n <a href=\"/blog/entry/74245\">Questions and doubts regarding Aliens DP trick</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a> →\r\n <a href=\"/blog/entry/8192\">Codeforces Round #190 — Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/hocky\" title=\"Candidate Master hocky\" class=\"rated-user user-violet\">hocky</a> →\r\n <a href=\"/blog/entry/95323\">FBHC wuining uw Day? Incwease uw stacc size! (ㅅ´ ˘ `)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/liouzhou_101\" title=\"International Master liouzhou_101\" class=\"rated-user user-orange\">liouzhou_101</a> →\r\n <a href=\"/blog/entry/87598\">Editorial of Codeforces Round #700</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/yeon_gist\" title=\"Newbie yeon_gist\" class=\"rated-user user-gray\">yeon_gist</a> →\r\n <a href=\"/blog/entry/121170\">plusMinusPermutation computing error</a>\r\n <img alt=\"Text created or updated\" title=\"Text created or updated\" src=\"//codeforces.org/s/81027/images/icons/x-update-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/altforminuscontribution\" title=\"Newbie altforminuscontribution\" class=\"rated-user user-gray\">altforminuscontribution</a> →\r\n <a href=\"/blog/entry/121162\">My screen get unexpectedly big, what should I do</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/atcoder_official\" title=\"Unrated, atcoder_official\" class=\"rated-user user-black\">atcoder_official</a> →\r\n <a href=\"/blog/entry/121120\">We will hold UNIQUE VISION Programming Contest 2023 Autumn(AtCoder Beginner Contest 323)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/YouStill_DontKnowMeYet\" title=\"Candidate Master YouStill_DontKnowMeYet\" class=\"rated-user user-violet\">YouStill_DontKnowMeYet</a> →\r\n <a href=\"/blog/entry/117659\">[GYM] Al-Baath Collegiate Programming Contest 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/ankancool\" title=\"Expert ankancool\" class=\"rated-user user-blue\">ankancool</a> →\r\n <a href=\"/blog/entry/121136\">Invitation to AstroByte 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/GeZhiyuan\" title=\"Grandmaster GeZhiyuan\" class=\"rated-user user-red\">GeZhiyuan</a> →\r\n <a href=\"/blog/entry/120943\">Codeforces Round 901 (Div. 1, Div. 2) Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a> →\r\n <a href=\"/blog/entry/120772\">PSA: Increase your stack size before the Meta Hacker Cup, here's how</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/dino_merlin\" title=\"Expert dino_merlin\" class=\"rated-user user-blue\">dino_merlin</a> →\r\n <a href=\"/blog/entry/121145\">Intuitive approach for CEOI Kangaroo?</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/icecuber\" title=\"Grandmaster icecuber\" class=\"rated-user user-red\">icecuber</a> →\r\n <a href=\"/blog/entry/70018\">CSES DP section editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bn00b\" title=\"Newbie Bn00b\" class=\"rated-user user-gray\">Bn00b</a> →\r\n <a href=\"/blog/entry/98820\">[FEATURE REQUEST : ATCODER] TOPICS TAGS AND SORTING BY SOLVE COUNT</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a> →\r\n <a href=\"/blog/entry/121163\">AtCoder Regular Contest 166 Announcement</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/windva\" title=\"Grandmaster windva\" class=\"rated-user user-red\">windva</a> →\r\n <a href=\"/blog/entry/120644\">Codeforces Round 899 (Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Misa-Misa\" title=\"Expert Misa-Misa\" class=\"rated-user user-blue\">Misa-Misa</a> →\r\n <a href=\"/blog/entry/121157\">Someone please help me understand this.</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/shivam565\" title=\"Specialist shivam565\" class=\"rated-user user-cyan\">shivam565</a> →\r\n <a href=\"/blog/entry/108348\">Total number of subarrays with sum atmost k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n </ul>\r\n </div>\r\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/recent-actions\">Detailed →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n</div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li><a\r\n href=\"/profile/gridnevvvit\">gridnevvvit</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/gridnevvvit\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/gridnevvvit\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/gridnevvvit\">Submissions</a></li>\r\n <li><a\r\n href=\"/groups/with/gridnevvvit\">Groups</a></li>\r\n <li><a\r\n href=\"/contests/with/gridnevvvit\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/gridnevvvit\">Problemsetting</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/gridnevvvit\" style=\"text-decoration:none;color:black !important;\">gridnevvvit's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"10638\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/10583\"> <p>Editorial Codeforces Round #227 (Div. 2)</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/gridnevvvit\" title=\"Candidate Master gridnevvvit\" class=\"rated-user user-violet\">gridnevvvit</a>,\r\n <span class=\"format-humantime\" title=\"Jan/30/2014 22:21\">10 years ago</span>,\r\n translation,\r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><h3><a href=\"/contest/387/problem/A\" title=\"Codeforces Round 227 (Div. 2)\">387A - George and Sleep</a></h3><p>I will describe the simple solution. Let George woke up in the <span class=\"tex-span\"><i>h</i><sub class=\"lower-index\">0</sub></span> hours and <span class=\"tex-span\"><i>m</i><sub class=\"lower-index\">0</sub></span> minutes, and he slept for <span class=\"tex-span\"><i>h</i><sub class=\"lower-index\">1</sub></span> hours and <span class=\"tex-span\"><i>m</i><sub class=\"lower-index\">1</sub></span> minutes. Let's get the number <span class=\"tex-span\"><i>h</i><sub class=\"lower-index\"><i>p</i></sub> = <i>h</i><sub class=\"lower-index\">0</sub> - <i>h</i><sub class=\"lower-index\">1</sub></span> and <span class=\"tex-span\"><i>m</i><sub class=\"lower-index\"><i>p</i></sub> = <i>m</i><sub class=\"lower-index\">0</sub> - <i>m</i><sub class=\"lower-index\">1</sub></span>. If <span class=\"tex-span\"><i>m</i><sub class=\"lower-index\"><i>p</i></sub> < 0</span>, then you should add to <span class=\"tex-span\"><i>m</i><sub class=\"lower-index\"><i>p</i></sub></span> <span class=\"tex-span\">60</span> minutes and subtract from <span class=\"tex-span\"><i>h</i><sub class=\"lower-index\"><i>p</i></sub></span> one hour. After that if <span class=\"tex-span\"><i>h</i><sub class=\"lower-index\"><i>p</i></sub> < 0</span>, then add to it <span class=\"tex-span\">24</span> hours. You can print the answer in C++ by using the following line:</p> <pre><code>printf("%02d:%02d", h[p], m[p]).\n</code></pre><p>The complexity is <span class=\"tex-span\"><i>O</i>(1)</span> time and <span class=\"tex-span\"><i>O</i>(1)</span> memory.</p><p>Author's solution: <a href=\"/contest/387/submission/5850831\" title=\"Submission 5850831 by gridnevvvit\">5850831</a></p><h3><a href=\"/contest/387/problem/B\" title=\"Codeforces Round 227 (Div. 2)\">387B - George and Round</a></h3><p>Consider the number of requirements of the difficulties, which we will cover, and we will come up with and prepare new problem to cover other requirements. It is clear that if we decided to meet the <span class=\"tex-span\"><i>i</i></span> out of <span class=\"tex-span\"><i>n</i></span> requirements, it would be better to take those with minimal complexity. Let's simplify <span class=\"tex-span\"><i>i</i></span> most difficult problems to lightest requirements. If all goes well, then we update the answer by value <span class=\"tex-span\"><i>n</i> - <i>i</i></span>.</p><p>The complexity is: <span class=\"tex-span\"><i>O</i>(<i>n</i><sup class=\"upper-index\">2</sup>)</span> time / <span class=\"tex-span\"><i>O</i>(<i>n</i>)</span> memory. Note, that there is an solution with complexity <span class=\"tex-span\"><i>O</i>(<i>n</i> + <i>m</i>)</span>.</p><p>Author's solution: <a href=\"/contest/387/submission/5850888\" title=\"Submission 5850888 by gridnevvvit\">5850888</a></p><h3><a href=\"/contest/387/problem/C\" title=\"Codeforces Round 227 (Div. 2)\">387C - George and Number</a></h3><p>Let's obtain the following irreducible representation of a number <span class=\"tex-span\"><i>p</i> = <i>a</i><sub class=\"lower-index\">1</sub> + <i>a</i><sub class=\"lower-index\">2</sub> + ... + <i>a</i><sub class=\"lower-index\"><i>k</i></sub></span>, where <span class=\"tex-span\"> + </span> is a concatenation, and numbers <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> have the form <span class=\"tex-span\"><i>x</i>00..000</span> (x — is non zero digit, and after that there are only zeroes). Let's determine largest index <span class=\"tex-span\"><i>i</i></span>, such that <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub> + <i>a</i><sub class=\"lower-index\">2</sub> + ... + <i>a</i><sub class=\"lower-index\"><i>i</i> - 1</sub> < <i>a</i><sub class=\"lower-index\"><i>i</i></sub></span>. If there are no such index <span class=\"tex-span\"><i>i</i></span> then <span class=\"tex-span\"><i>i</i> = 1</span>. After that is <span class=\"tex-span\"><i>k</i> - <i>i</i> + 1</span>. You can compare numbers by using length of number and first digit. You can prove these solution as home task : )</p><p>The complexity is: <span class=\"tex-span\"><i>O</i>(<i>n</i>)</span> time / <span class=\"tex-span\"><i>O</i>(<i>n</i>)</span> memory.</p><p>Author's solution: <a href=\"/contest/387/submission/5850919\" title=\"Submission 5850919 by gridnevvvit\">5850919</a></p><h3><a href=\"/contest/387/problem/D\" title=\"Codeforces Round 227 (Div. 2)\">387D - George and Interesting Graph</a></h3><p>To solve this problem you should know about bipartite matching.</p><p>Let's consider the center of graph <span class=\"tex-span\"><i>i</i></span>. After that let's remove arcs that have form <span class=\"tex-span\">(<i>i</i>, <i>u</i>)</span> or <span class=\"tex-span\">(<i>u</i>, <i>i</i>)</span>. Let's there are <span class=\"tex-span\"><i>cntWithI</i></span> arcs of such type. Let's <span class=\"tex-span\"><i>Other</i> = <i>m</i> - <i>CntWithI</i></span> — number of other arcs.</p><p>After that we should found maximal bipartite matching on the bipartite graph. This graph has following idea: left part of this graph is indegrees of all vertexes except vertex <span class=\"tex-span\"><i>i</i></span>, right part of this graph is outdegrees of all vertexes except vertex <span class=\"tex-span\"><i>i</i></span>. Also if there an arc <span class=\"tex-span\">(<i>i</i>, <i>j</i>)</span> in our graph then in our bipartite graph there an arc <span class=\"tex-span\">(<i>i</i>, <i>j</i>)</span>, where <span class=\"tex-span\"><i>i</i></span> — vertex from left part, <span class=\"tex-span\"><i>j</i></span> — vertex from the right part. Let's size of bipartite matching on the bipartite graph equals to <span class=\"tex-span\"><i>leng</i></span>. Then answer for the current vertex <span class=\"tex-span\"><i>i</i></span> equals to <span class=\"tex-span\">2<i>n</i> - 1 - <i>cntWithI</i> + <i>Other</i> - <i>leng</i> + (<i>n</i> - 1) - <i>leng</i></span>. After that you should update global answer. Why it is correct? It is simple to understand that if we will found bipartite matching on the bipartite graph we will cover maximal number of requirements on in/out degrees. Because of that, we will remove all other arcs, except of maximal matching, and after that we will add this maximal matching to full matching by adding <span class=\"tex-span\">(<i>n</i> - 1) - <i>leng</i></span> arcs. Note, it is important, that self-loops are not forbidden. Withoud self-loops problem is very hard, I think. </p><p>The complexity is: <span class=\"tex-span\"><i>O</i>(<i>n</i><sup class=\"upper-index\">2</sup><i>m</i>)</span> time / <span class=\"tex-span\"><i>O</i>(<i>n</i> + <i>m</i>)</span> memory.</p><p><a href=\"/contest/387/submission/5850946\" title=\"Submission 5850946 by gridnevvvit\">5850946</a></p><h3><a href=\"/contest/387/problem/E\" title=\"Codeforces Round 227 (Div. 2)\">387E - George and Cards</a></h3><p>Let's calculate arrays <span class=\"tex-span\"><i>pos</i>[<i>i</i>]</span> — position of number <span class=\"tex-span\"><i>i</i></span> in permutation <span class=\"tex-span\"><i>p</i></span> and <span class=\"tex-span\"><i>need</i>[<i>i</i>]</span> — equals to one if we should remove number <span class=\"tex-span\"><i>i</i></span> from permutation <span class=\"tex-span\"><i>p</i></span>, and zero if we shouldn't remove <span class=\"tex-span\"><i>i</i></span> from permutation <span class=\"tex-span\"><i>p</i></span>. </p><p>Let's <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub>, <i>a</i><sub class=\"lower-index\">2</sub>, ..., <i>a</i><sub class=\"lower-index\"><i>n</i> - <i>k</i></sub></span> — numvers, which we should remove. It is clear to understand that we should remove these number in increasing order. It is simple to proof this statement.</p><p>Let's iterate <span class=\"tex-span\"><i>i</i></span> from to <span class=\"tex-span\">1</span> to <span class=\"tex-span\"><i>n</i></span>. Also we the current number we will have special set (set <>in с++, TreeSet in Java) of positions of non-erased numbers (which are smaller then <span class=\"tex-span\"><i>i</i></span>) of permutation. These position can create an ``obstacle'' for current position of number <span class=\"tex-span\"><i>i</i></span>. It is simple to support this special set. Also we can add to this set numbers <span class=\"tex-span\"> - 1</span> and <span class=\"tex-span\"><i>n</i></span>. Now it is easy to find length og the maximal sub-array, where current number is a minimum. You can prosess such query by using standart functions of programming language (lower and higher in Java). After that we should use Fenwick tree to determine quantity of numbers which are not removed on the maximal sub-array.</p><p>The complexity is: <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/5e7dae7c1838af7ba7570bdf02ff61029b043be6.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> time / <span class=\"tex-span\"><i>O</i>(<i>n</i>)</span> memory.</p><p>Very simple implementation on Java: <a href=\"/contest/387/submission/5850986\" title=\"Submission 5850986 by gridnevvvit\">5850986</a></p></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/387\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 227 (Div. 2)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-6883-10638\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"6883\",\n blogEntryId: \"10583\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n <div style=\"font-size: 1.1rem;line-height: 11px;\">\r\n <img style=\"vertical-align: middle;\" src=\"//codeforces.org/s/81027/images/blog/tags.png\" title=\"Tags\" alt=\"Tags\"/>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=editorial\" class=\"tag notice\" style=\"text-decoration: none;\">editorial</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=codeforces\" class=\"tag notice\" style=\"text-decoration: none;\">codeforces</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=round\" class=\"tag notice\" style=\"text-decoration: none;\">round</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=227\" class=\"tag notice\" style=\"text-decoration: none;\">227</a>\r\n </span>\r\n </div>\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-10638\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+35</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-10638\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/gridnevvvit\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/gridnevvvit\">\n gridnevvvit\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Jan/30/2014 22:21\">10 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/10583#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/10583#comments\">\n 25\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"10654\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (25)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159495\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/coolbun\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/coolbun\" title=\"Candidate Master coolbun\" class=\"rated-user user-violet\">coolbun</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/30/2014 22:54\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159495\" href=\"?#comment-159495\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159495\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"2\"\r\n data-commentUserId=\"90437\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+2</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159495\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can anyone explain the solution of problem C</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159495 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159495 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159495\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159552\" commentParentId=\"159495\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/prakhar3agrwal\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/45384/avatar/63c5e4d25f17da6b.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/prakhar3agrwal\" title=\"Expert prakhar3agrwal\" class=\"rated-user user-blue\">prakhar3agrwal</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/31/2014 14:13\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159552\" href=\"?#comment-159552\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159495\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159552\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"45384\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159552\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Well my approach to this question was different , just start from the beginning and take 2 string variables. Let the variables be g and l (for global and local resp.),now g will store the substring starting from the beginning till just before the index from where l started.Now if the next character is '0' then we are bound to include it in the local string otherwise just see that whether g>=l or not , if yes then increase ans by 1 and include l in g (g+=l) and clear l, else make ans=1, g=g+l and clear l. This is because if g<l then obviously the substring in l should occur before g in resultant substring (meaning it will be "lg" instead of "gl"). Finally print the ans........</p><p>Hope it helps.... </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159552 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159552 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159552\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159577\" commentParentId=\"159552\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/eddycael\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/52186/avatar/a0efb238d6a68050.jpg'/> </a>\n <div><a href=\"/profile/eddycael\" title=\"Specialist eddycael\" class=\"rated-user user-cyan\">eddycael</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/31/2014 20:53\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159577\" href=\"?#comment-159577\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159552\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159577\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"52186\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159577\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Hello, (sorry for my poor english) My solution traverses the string with 2 pointers and whenever it encounters a string representing a smaller number than what's left then add 1 to the answer. It is not necessary to generate any substrings... Just analyze the representation of strings of equal length. Here's my solution: <a href=\"//codeforces.com/contest/387/submission/5858084\">solutionECMC</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159577 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159577 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159577\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159740\" commentParentId=\"159577\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/prakhar3agrwal\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/45384/avatar/63c5e4d25f17da6b.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/prakhar3agrwal\" title=\"Expert prakhar3agrwal\" class=\"rated-user user-blue\">prakhar3agrwal</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2014 08:26\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159740\" href=\"?#comment-159740\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159577\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159740\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"45384\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159740\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I am not generating any substring as such , it was the concept used in my solution, my time complexity is O(n).</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159740 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159740 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159740\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159553\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/jibon_ebong_shomoy\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/107227/avatar/d1546e81b26787b3.jpg'/> </a>\n <div><a href=\"/profile/jibon_ebong_shomoy\" title=\"Specialist jibon_ebong_shomoy\" class=\"rated-user user-cyan\">jibon_ebong_shomoy</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/31/2014 14:52\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159553\" href=\"?#comment-159553\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"159553\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"159553\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"107227\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159553\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I don't understand the solution of D . can anyone explain? what to do? why the last part of answer <code>(n-1)-leng</code> for?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159553 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159553 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159553\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159566\" commentParentId=\"159553\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/gridnevvvit\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/31163/avatar/db500a30a0b0a6f1.jpg'/> </a>\n <div><a href=\"/profile/gridnevvvit\" title=\"Candidate Master gridnevvvit\" class=\"rated-user user-violet\">gridnevvvit</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/31/2014 17:12\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159566\" href=\"?#comment-159566\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159553\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159566\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"31163\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159566\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>We will add some arcs to create prefect matching in graph</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159566 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159566 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159566\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"335415\" commentParentId=\"159553\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/u33how\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/216525/avatar/a0f0155335a1dd88.jpg'/> </a>\n <div><a href=\"/profile/u33how\" title=\"Expert u33how\" class=\"rated-user user-blue\">u33how</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/04/2017 17:52\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-335415\" href=\"?#comment-335415\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159553\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"335415\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"216525\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-335415\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I think the equation came from these :</p><p>ans = 2*(n-1); // for adding the (u,i)and(i,u) edges</p><p>ans = ans — (cntWithI) ; // they were already given, so we do not need to delete them,</p><p>ans = ans+1 ; // the center must have a self loop according to problem description.</p><p>ans = ans + Others ; // delete all the extra edges;</p><p>ans = ans — leng ; // do not have to delete the matching edges</p><p>ans = ans+ (n-1) ; // add n-1 self loops</p><p>ans = ans-leng ; // 'leng' number of vertices do not need self loop; </p><p>Hope it helps somebody.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-335415 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-335415 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-335415\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159679\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/raylee\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/135528/avatar/52549c9492fe7c04.jpg'/> </a>\n <div><a href=\"/profile/raylee\" title=\"Specialist raylee\" class=\"rated-user user-cyan\">raylee</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/02/2014 11:07\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159679\" href=\"?#comment-159679\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"159679\" revisionCount=\"13\" revision=\"13\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">13</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"159679\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"135528\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159679\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In the problem D, said "The complexity is: <span class=\"tex-span\"><i>O</i>(<i>n</i><sup class=\"upper-index\">2</sup> <i>m</i>)</span> time." But n and m (2 ≤ n ≤ 500, 1 ≤ m ≤ 1000). Can you explain why this complexity wont TLE? thank you.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159679 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159679 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159679\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159685\" commentParentId=\"159679\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/gridnevvvit\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/31163/avatar/db500a30a0b0a6f1.jpg'/> </a>\n <div><a href=\"/profile/gridnevvvit\" title=\"Candidate Master gridnevvvit\" class=\"rated-user user-violet\">gridnevvvit</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/02/2014 11:55\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159685\" href=\"?#comment-159685\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159679\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159685\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"31163\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159685\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Yes. First, let's calculate number of operations: it is about <span class=\"tex-span\">2 * 10<sup class=\"upper-index\">8</sup></span>. It is not so much. If you have good implementation of Kuhn, it would pass. Also, I know, that number of operation is much lower than <span class=\"tex-span\">2 * 10<sup class=\"upper-index\">8</sup></span>.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159685 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159685 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159685\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159689\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/1nikhil9\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/60595/avatar/64f85d0070290be7.jpg'/> </a>\n <div><a href=\"/profile/1nikhil9\" title=\"Candidate Master 1nikhil9\" class=\"rated-user user-violet\">1nikhil9</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/02/2014 14:07\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159689\" href=\"?#comment-159689\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159689\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"60595\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159689\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Test case 4 for Problem D says N = 153, M = 392. But there are only 391 edges in the input file.</p><p><a href=\"//codeforces.com/contest/387/submission/5868021\">http://codeforces.com/contest/387/submission/5868021</a></p><p>Am I misunderstanding something? Thanks.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159689 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159689 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159689\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159694\" commentParentId=\"159689\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/gridnevvvit\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/31163/avatar/db500a30a0b0a6f1.jpg'/> </a>\n <div><a href=\"/profile/gridnevvvit\" title=\"Candidate Master gridnevvvit\" class=\"rated-user user-violet\">gridnevvvit</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/02/2014 15:06\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159694\" href=\"?#comment-159694\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159689\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159694\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"31163\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159694\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Testcase is valid.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159694 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159694 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159694\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"160860\" commentParentId=\"159694\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/khrak\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/128936/avatar/6d9b38f723c23a83.jpg'/> </a>\n <div><a href=\"/profile/khrak\" title=\"Expert khrak\" class=\"rated-user user-blue\">khrak</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/07/2014 20:07\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-160860\" href=\"?#comment-160860\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159694\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"160860\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"128936\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-160860\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>What does n variable mean in C problem tutorial? </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-160860 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-160860 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-160860\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"160876\" commentParentId=\"160860\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/gridnevvvit\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/31163/avatar/db500a30a0b0a6f1.jpg'/> </a>\n <div><a href=\"/profile/gridnevvvit\" title=\"Candidate Master gridnevvvit\" class=\"rated-user user-violet\">gridnevvvit</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/08/2014 00:57\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-160876\" href=\"?#comment-160876\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-160860\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"160876\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"31163\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-160876\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>n is the length of the number from the input.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-160876 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-160876 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-160876\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"160894\" commentParentId=\"160876\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/khrak\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/128936/avatar/6d9b38f723c23a83.jpg'/> </a>\n <div><a href=\"/profile/khrak\" title=\"Expert khrak\" class=\"rated-user user-blue\">khrak</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/08/2014 11:15\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-160894\" href=\"?#comment-160894\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-160876\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"160894\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"128936\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-160894\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>So, for 800101 we have a1 = 800, a2 = 10, a3 = 1, and n = 6. what value has i for this example, 1 or -1? </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-160894 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-160894 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-160894\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"160913\" commentParentId=\"160894\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/gridnevvvit\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/31163/avatar/db500a30a0b0a6f1.jpg'/> </a>\n <div><a href=\"/profile/gridnevvvit\" title=\"Candidate Master gridnevvvit\" class=\"rated-user user-violet\">gridnevvvit</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/08/2014 14:34\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-160913\" href=\"?#comment-160913\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-160894\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"160913\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"31163\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-160913\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>i equals to -1. I understood, that there is an small mistake: answer is <span class=\"tex-span\"><i>k</i> - <i>i</i> + 1</span></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-160913 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-160913 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-160913\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"160924\" commentParentId=\"160913\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/khrak\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/128936/avatar/6d9b38f723c23a83.jpg'/> </a>\n <div><a href=\"/profile/khrak\" title=\"Expert khrak\" class=\"rated-user user-blue\">khrak</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/08/2014 16:02\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-160924\" href=\"?#comment-160924\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-160913\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"160924\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"128936\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-160924\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Sorry for so many questions, but I can't still understand how we count answer answer for 800101. here k equals 3, i equals -1 (as you said), then answer should be k — i + 1 = 3 — (-1) + 1 = 5 when answer here is 3.. What I didn't understand correctly? </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-160924 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-160924 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-160924\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"160928\" commentParentId=\"160924\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/gridnevvvit\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/31163/avatar/db500a30a0b0a6f1.jpg'/> </a>\n <div><a href=\"/profile/gridnevvvit\" title=\"Candidate Master gridnevvvit\" class=\"rated-user user-violet\">gridnevvvit</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/08/2014 17:23\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-160928\" href=\"?#comment-160928\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-160924\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"160928\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"31163\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-160928\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Oh, it's my mistake. If there is no such index, index i should be equals to 1, yes.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-160928 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-160928 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-160928\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"160929\" commentParentId=\"160928\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/khrak\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/128936/avatar/6d9b38f723c23a83.jpg'/> </a>\n <div><a href=\"/profile/khrak\" title=\"Expert khrak\" class=\"rated-user user-blue\">khrak</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/08/2014 17:27\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-160929\" href=\"?#comment-160929\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-160928\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"160929\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"128936\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-160929\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Okey. Then I understand and I'll think about proof. Thank you! :) </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-160929 en true\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-160929 en true\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-160929\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"161379\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/rohitjv\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/107177/avatar/3326d08f28613bd4.jpg'/> </a>\n <div><a href=\"/profile/rohitjv\" title=\"Expert rohitjv\" class=\"rated-user user-blue\">rohitjv</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/12/2014 21:33\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-161379\" href=\"?#comment-161379\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"161379\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"107177\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-161379\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In problem C, the definition of the array <em>need[i]</em> in the description does not match with the code provided. The actual definition of <em>need[i]</em> should be : need[i] — equals to <strong>0</strong> if we should remove number i from permutation p, and <strong>1</strong> if we shouldn't remove i from permutation p. Please correct me if I am wrong.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-161379 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-161379 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-161379\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"161380\" commentParentId=\"161379\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/gridnevvvit\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/31163/avatar/db500a30a0b0a6f1.jpg'/> </a>\n <div><a href=\"/profile/gridnevvvit\" title=\"Candidate Master gridnevvvit\" class=\"rated-user user-violet\">gridnevvvit</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/12/2014 21:56\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-161380\" href=\"?#comment-161380\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-161379\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"161380\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"31163\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-161380\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Yes, description does not match with the code provided. There are only ideas in editorial, so there are can be differences. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-161380 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-161380 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-161380\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"161811\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Nakochi\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/101746/avatar/ccfafe3f7587f95d.jpg'/> </a>\n <div><a href=\"/profile/Nakochi\" title=\"Expert Nakochi\" class=\"rated-user user-blue\">Nakochi</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/17/2014 18:23\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-161811\" href=\"?#comment-161811\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"161811\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"101746\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-161811\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Problem C is really a challenge for me!!! Orz!!!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-161811 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-161811 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-161811\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"161820\" commentParentId=\"161811\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Nodir.Daminov\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/71439/avatar/d6d2016f6dfe5ecd.jpg'/> </a>\n <div><a href=\"/profile/Nodir.Daminov\" title=\"Candidate Master Nodir.Daminov\" class=\"rated-user user-violet\">Nodir.Daminov</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/17/2014 19:19\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-161820\" href=\"?#comment-161820\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-161811\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"161820\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"71439\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-161820\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Who cares ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-161820 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-161820 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-161820\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"161902\" commentParentId=\"161820\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Nakochi\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/101746/avatar/ccfafe3f7587f95d.jpg'/> </a>\n <div><a href=\"/profile/Nakochi\" title=\"Expert Nakochi\" class=\"rated-user user-blue\">Nakochi</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/18/2014 18:14\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-161902\" href=\"?#comment-161902\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-161820\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"161902\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"101746\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-161902\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Sorry, I misunderstood the problem. Now it's much easier. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-161902 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-161902 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-161902\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"161903\" commentParentId=\"161902\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Nodir.Daminov\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/71439/avatar/d6d2016f6dfe5ecd.jpg'/> </a>\n <div><a href=\"/profile/Nodir.Daminov\" title=\"Candidate Master Nodir.Daminov\" class=\"rated-user user-violet\">Nodir.Daminov</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/18/2014 18:25\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-161903\" href=\"?#comment-161903\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-161902\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"161903\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"71439\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-161903\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Who cares ???</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-161903 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-161903 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-161903\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"161904\" commentParentId=\"161903\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Nakochi\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/101746/avatar/ccfafe3f7587f95d.jpg'/> </a>\n <div><a href=\"/profile/Nakochi\" title=\"Expert Nakochi\" class=\"rated-user user-blue\">Nakochi</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/18/2014 18:54\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-161904\" href=\"?#comment-161904\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-161903\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"161904\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"101746\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-161904\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Seems you care. :D</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-161904 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-161904 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-161904\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n <br/>\r\n\r\n<div id=\"editBox-10654\" style=\"width:50em;display:none;\">\r\n <div class=\"previewBody\" style=\"border: 1px solid #d4d4d4; margin-bottom: 0.5em; padding: 0.25em; display:none;\"> </div>\r\n <div style=\"width: 1px\"> </div>\r\n <div class=\"commentLocale\" style=\"position: relative; top: 0.5em;left:4px;display: none;\">\r\n <input type=\"radio\" name=\"locale\" value=\"en\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In English</span>\r\n <input style=\"margin-left:1em\" type=\"radio\" name=\"locale\" value=\"ru\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In Russian</span>\r\n </div>\r\n <textarea data-drafts-id=\"CommentReplyFrame\" class=\"wysiwyg\" name=\"editContent\" rows=\"20\" style=\"width:99%;\"></textarea>\r\n <div class=\"error error__content\"></div>\r\n <div style=\"text-align:center;\">\r\n <input type=\"button\" name=\"preview\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Preview\"/>\r\n <input type=\"button\" name=\"save\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Save\"/>\r\n </div>\r\n</div>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n\r\nvar firstPreview10654 = true;\r\nvar lastPreviewContent10654 = '';\r\n\r\nif (!window.moveCommentRevision) {\r\n moveCommentRevision = function(e, dir) {\r\n var p = e.parent();\r\n var revisionCount = parseInt(p.attr(\"revisionCount\"));\r\n var revision = parseInt(p.attr(\"revision\"));\r\n var next = revision + dir;\r\n var commentId = p.attr(\"commentId\");\r\n if (next >= 1 && next <= revisionCount) {\r\n $.post(\r\n \"/data/comment-data\",\r\n {action: \"revision\", commentId: commentId, revision: next},\r\n function(json) {\r\n if (json.success == \"true\") {\r\n var parentDiv = e;\r\n\r\n while (parentDiv !== null && (parentDiv[0].nodeName.toLowerCase() !== \"td\" || !parentDiv.hasClass(\"right\"))) {\r\n parentDiv = parentDiv.parent();\r\n }\r\n\r\n if (parentDiv === null) {\r\n return;\r\n }\r\n\r\n parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\").html(json.content);\r\n Codeforces.setupSpoilers(parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\"));\r\n p.attr(\"revision\", next);\r\n p.find(\"span.revision\").text(next);\r\n if (next == 1) {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"visible\");\r\n }\r\n if (next == revisionCount) {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"visible\");\r\n }\r\n\r\n window.updateTypography();\r\n MathJax.Hub.Typeset();\r\n } else {\r\n alert(e.error);\r\n }\r\n },\r\n \"json\"\r\n );\r\n }\r\n };\r\n}\r\n\r\n$(\"div[commentableId=10654] a.leftRevision\").click(function () {\r\n window.moveCommentRevision($(this), -1);\r\n return false;\r\n});\r\n\r\n$(\"div[commentableId=10654] a.rightRevision\").click(function () {\r\n window.moveCommentRevision($(this), +1);\r\n return false;\r\n});\r\n\r\n\r\n\r\n });\n </script>\n\r\n\r\n <script src=\"//codeforces.org/s/81027/js/swfobject-2.2.min.js\" type=\"text/javascript\"></script>\n <script src=\"//codeforces.org/s/81027/js/ftaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n if (window.evercookie) {\n var ec = new evercookie({\n history: false,\n silverlight: false,\n baseurl: '',\n asseturi: '/assets',\n phpuri: '/2fdcd78',\n pngPath: '/eps',\n etagPath: '/ees',\n cachePath: '/ecs'\n });\n\n var randomNumber = function () {\n return Math.random().toString(36).substr(2);\n };\n\n var randomToken = function () {\n return (randomNumber() + randomNumber()).substring(0, 18);\n };\n\n window._ftaa = \"\";\n\n ec.get(\"70a7c28f3de\", function (value) {\n window._ftaa = value;\n if (!window._ftaa) {\n window._ftaa = randomToken();\n ec.set(\"70a7c28f3de\", window._ftaa);\n }\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n } else {\n window._ftaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\n <script src=\"//codeforces.org/s/81027/js/bfaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n var fpCallback = function() {\n Fingerprint2.get({}, function(components) {\n window._bfaa = Fingerprint2.x64hash128(components.map(function (pair) { return pair.value }).join(), 31);\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n };\n if (typeof Fingerprint2 !== 'undefined') {\n if (window.requestIdleCallback) {\n requestIdleCallback(fpCallback)\n } else {\n setTimeout(fpCallback, 500)\n }\n } else {\n window._bfaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"a.new-root-comment\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n\r\n $(\".comment-table .reply a\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".vote-for-comment\").mouseover(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").mouseout(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").click(function () {\r\n var vote = $(this);\r\n var commentId = $(this).parent().attr(\"commentid\");\r\n var commentRating = $(this).parent().attr(\"data-commentRating\");\r\n var direction = $(this).attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n $.post(\"/data/comment/vote\", {commentId: commentId, _tta: Codeforces.tta(), vote: direction, commentRating: commentRating}, function(data) {\r\n if (direction != 0 && !ownComment && data[\"success\"] == \"true\") {\r\n vote.parent().find(\".vote-for-comment\").attr(\"voteDirection\", 0);\r\n if (direction == 1)\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n else {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.closest(\".CommentVoteFrame\").find(\".ComplaintFrame\").css(\"display\", \"inline-block\");\r\n }\r\n vote.find(\"img\").attr(\"popacity\", \"1.0\");\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n vote.parent().find(\".commentRating\").html(data[\"commentRating\"]);\r\n }\r\n Codeforces.showMessage(data[\"message\"]);\r\n }, \"json\");\r\n return false;\r\n });\r\n\r\n $(\".negative-comment-vote\").closest(\".comment-table\").addClass(\"comment-bad\");\r\n\r\n $(\".troll-comment-vote\").closest(\".comment\").css(\"display\", \"none\");\r\n\r\n $(\".too-negative-comment-vote\").closest(\".comment-table\").each(function () {\r\n var e = $(this);\r\n e.addClass(\"comment-too-bad\");\r\n var commentId = e.attr(\"commentId\");\r\n $(\"<div class='bad-comment-replacement ttypography'>The comment is hidden because of too negative feedback, click <a href=# class=show-bad-comment-link>here</a> to view it</div>\").appendTo(\r\n e.find(\".right\")\r\n );\r\n e.find(\".comment-content\").hide();\r\n e.find(\".show-bad-comment-link\").click(function () {\r\n e.find(\".comment-content\").show();\r\n e.find(\".bad-comment-replacement\").hide();\r\n return false;\r\n });\r\n });\r\n });\n </script>\n </div>\r\n\r\n <style type=\"text/css\">\r\n .new-comments-box {\r\n padding: 0.5em;\r\n width: 22px;\r\n font-size: 1.3rem;\r\n font-weight: bold !important;\r\n\r\n position: fixed;\r\n top: 40%;\r\n right: 0;\r\n opacity: 0.2;\r\n color: white;\r\n text-align: center;\r\n\r\n border: 1px solid #222;\r\n background-color: #888 !important;\r\n border-radius: 3px;\r\n -moz-border-radius: 3px;\r\n -webkit-border-radius: 3px;\r\n }\r\n\r\n .new-comments-box:hover {\r\n opacity: 1;\r\n }\r\n\r\n .new-comments-box .dir:hover {\r\n background: #3B5998 !important;\r\n cursor: pointer;\r\n }\r\n </style>\r\n\r\n <div class=\"new-comments-box\" data-position=\"outside\" data-index=\"-1\" style=\"display: none;\">\r\n <div class=\"up dir\" title=\"Ctrl+Up\">↑<hr/>\r\n </div>\r\n <div class=\"info\" title=\"New comments\"></div>\r\n <div class=\"down dir\" title=\"Ctrl+Down\">\r\n <hr/>↓\r\n </div>\r\n </div>\r\n\r\n <script>\r\n $(\".show-archived-checkbox\").change(function () {\r\n const checked = $(this).is(\":checked\");\r\n $.post(\"/data/comment-data\", {action: \"setShowArchived\", checked}, function (json) {\r\n if (json[\"success\"] !== \"true\") {\r\n alert(json[\"error\"]);\r\n } else {\r\n if (checked) {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are now displayed\")\r\n } else {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are no longer displayed\")\r\n }\r\n }\r\n });\r\n return false;\r\n });\r\n\r\n function gotoComment(direction) {\r\n var box = $(\".new-comments-box\");\r\n var index = parseInt(box.attr(\"data-index\"));\r\n if (index == -1)\r\n index = 0;\r\n else\r\n index = Math.max(0, Math.min(parseInt(box.find(\".info\").text()) - 1, index + direction));\r\n box.attr(\"data-index\", index);\r\n var comment = $($(\".comment .highlight-blue[commentId]\").get(index));\r\n $('html, body').animate({\r\n 'scrollTop': Math.max(0, comment.offset().top - ($(window).height() - comment.height()) / 2)\r\n });\r\n return false;\r\n }\r\n\r\n $(\".new-comments-box .down\").click(function () {\r\n return gotoComment(1);\r\n });\r\n\r\n $(\".new-comments-box .up\").click(function () {\r\n return gotoComment(-1);\r\n });\r\n\r\n $(document).keydown(function (e) {\r\n var code = (e.keyCode ? e.keyCode : e.which);\r\n if (e.ctrlKey) {\r\n if (code == 38 || code == 40) {\r\n gotoComment(code - 39);\r\n }\r\n }\r\n });\r\n\r\n var newCommentCount = $(\".comment .highlight-blue[commentId]\").length;\r\n if (newCommentCount > 0) {\r\n $(\".new-comments-box .info\").text(newCommentCount);\r\n $(\".new-comments-box\").show();\r\n }\r\n\r\n $('table.comment-table').mouseenter(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").addClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n\r\n $('table.comment-table').mouseleave(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").removeClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n </script>\r\n\r\n\r\n\r\n <script>\r\n function adjustTopicComplainFrames() {\r\n let topicIds = [];\r\n\r\n $(\".has-topic-id\").each(function () {\r\n const $this = $(this);\r\n const topicId = $this.attr(\"topicId\");\r\n if (topicId) {\r\n topicIds.push(topicId);\r\n }\r\n });\r\n\r\n $.post(\"/data/topics\", {\r\n action: \"findComplainableTopicIds\",\r\n topicIds: topicIds.join(\",\")\r\n }, function (json) {\r\n if (json[\"success\"] === \"true\") {\r\n for (const topicId of json[\"complainableTopicIds\"].split(\",\")) {\r\n $(\".has-topic-id[topicId=\" + topicId + \"]\").each(function () {\r\n $(this).find(\".meta .ComplaintFrame\").css(\"display\", \"inline-block\");\r\n });\r\n }\r\n }\r\n }, \"json\");\r\n }\r\n\r\n $(function () {\r\n adjustTopicComplainFrames();\r\n })\r\n </script>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-10638\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 10638, _tta: Codeforces.tta(), topicRevisionId: 37197, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-10638\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 10638, _tta: Codeforces.tta(), topicRevisionId: 37197, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n </div>\r\n </div>\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 22:13:05</span> (h1).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/81027/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/81027/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/81027/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/81027/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-81027.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'812875999be52de2',t:'MTY5NjcwNTk4NS43NTIwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"}}},{"rowIdx":1957,"cells":{"problem_id":{"kind":"string","value":"387E"},"contest":{"kind":"string","value":"387"},"problem":{"kind":"string","value":"E"},"lang":{"kind":"string","value":"en"},"problem_title":{"kind":"string","value":"E. George and Cards"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">E. George and Cards</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>George is a cat, so he loves playing very much.</p><p>Vitaly put <span class=\"tex-span\"><i>n</i></span> cards in a row in front of George. Each card has one integer written on it. All cards had distinct numbers written on them. Let's number the cards from the left to the right with integers from <span class=\"tex-span\">1</span> to <span class=\"tex-span\"><i>n</i></span>. Then the <span class=\"tex-span\"><i>i</i></span>-th card from the left contains number <span class=\"tex-span\"><i>p</i><sub class=\"lower-index\"><i>i</i></sub></span> (<span class=\"tex-span\">1 ≤ <i>p</i><sub class=\"lower-index\"><i>i</i></sub> ≤ <i>n</i></span>). </p><p>Vitaly wants the row to have exactly <span class=\"tex-span\"><i>k</i></span> cards left. He also wants the <span class=\"tex-span\"><i>i</i></span>-th card from left to have number <span class=\"tex-span\"><i>b</i><sub class=\"lower-index\"><i>i</i></sub></span> written on it. Vitaly gave a task to George, to get the required sequence of cards using the remove operation <span class=\"tex-span\"><i>n</i> - <i>k</i></span> times.</p><p>In one <span class=\"tex-font-style-it\">remove operation</span> George can choose <span class=\"tex-span\"><i>w</i></span> (<span class=\"tex-span\">1 ≤ <i>w</i></span>; <span class=\"tex-span\"><i>w</i></span> is not greater than the current number of cards in the row) contiguous cards (contiguous subsegment of cards). Let's denote the numbers written on these card as <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">1</sub>, <i>x</i><sub class=\"lower-index\">2</sub>, ..., <i>x</i><sub class=\"lower-index\"><i>w</i></sub></span> (from the left to the right). After that, George can remove the card <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span>, such that <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub> ≤ <i>x</i><sub class=\"lower-index\"><i>j</i></sub></span> for each <span class=\"tex-span\"><i>j</i></span> <span class=\"tex-span\">(1 ≤ <i>j</i> ≤ <i>w</i>)</span>. After the described operation George gets <span class=\"tex-span\"><i>w</i></span> pieces of sausage.</p><p>George wondered: what maximum number of pieces of sausage will he get in total if he reaches his goal and acts optimally well? Help George, find an answer to his question!</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains integers <span class=\"tex-span\"><i>n</i></span> and <span class=\"tex-span\"><i>k</i></span> (<span class=\"tex-span\">1 ≤ <i>k</i> ≤ <i>n</i> ≤ 10<sup class=\"upper-index\">6</sup></span>) — the initial and the final number of cards.</p><p>The second line contains <span class=\"tex-span\"><i>n</i></span> distinct space-separated integers <span class=\"tex-span\"><i>p</i><sub class=\"lower-index\">1</sub>, <i>p</i><sub class=\"lower-index\">2</sub>, ..., <i>p</i><sub class=\"lower-index\"><i>n</i></sub></span> (<span class=\"tex-span\">1 ≤ <i>p</i><sub class=\"lower-index\"><i>i</i></sub> ≤ <i>n</i></span>) — the initial row of cards. </p><p>The third line contains <span class=\"tex-span\"><i>k</i></span> space-separated integers <span class=\"tex-span\"><i>b</i><sub class=\"lower-index\">1</sub>, <i>b</i><sub class=\"lower-index\">2</sub>, ..., <i>b</i><sub class=\"lower-index\"><i>k</i></sub></span> — the row of cards that you need to get. It is guaranteed that it's possible to obtain the given row by using the remove operation for <span class=\"tex-span\"><i>n</i> - <i>k</i></span> times.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print a single integer — the maximum number of pieces of sausage that George can get if he acts optimally well.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>3 2<br/>2 1 3<br/>1 3<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>10 5<br/>1 2 3 4 5 6 7 8 9 10<br/>2 4 6 8 10<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>30<br/></pre></div></div></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"09bc46bb5d4d207e3531621f04accde5\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - E - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"1d8414af0a90e113b8a49898336bf2bc6a1719bc\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - E - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/73366/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/73366/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/73366/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/73366/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/73366/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/73366/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/73366/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/73366/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/73366/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/73366/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/73366/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/73366/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/73366/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/73366/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/sidebar-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/a037fe51637846d9c7c725713cd840ea/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='09bc46bb5d4d207e3531621f04accde5'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/73366/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/73366/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fcontest%2F387%2Fproblem%2FE%3Flocale%3Den\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"current\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='09bc46bb5d4d207e3531621f04accde5'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:100%;\"><a style=\"color: black\" href=\"/contest/387\">Codeforces Round 227 (Div. 2)</a></th>\n </tr>\n <tr>\n <td class=\"left bottom\" colspan=\"1\"><span class=\"contest-state-phase\">Finished</span></td>\n </tr>\n </tbody>\n </table>\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Practice?\n <div class=\"top-links\">\n </div>\n </div>\n<div>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Want to solve the contest problems after the official contest ends? Just register for practice and you will be able to submit solutions.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"\" method=\"post\"><input type='hidden' name='csrf_token' value='09bc46bb5d4d207e3531621f04accde5'/>\r\n <input type=\"hidden\" name=\"action\" value=\"registerForPractice\"/>\r\n <input type=\"submit\" name=\"submit\" value=\"Register for practice\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div> \r\n</div>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox ContestVirtualFrame borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Virtual participation <i class=\"sidebar-caption-icon las la-angle-down\"></i>\r\n\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\" \"\r\n\r\n data-page-url=\"/data/sidebarFrames\"\r\n\r\n>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests.\n\nIf you've seen these problems, a virtual contest is not for you - solve these problems in the archive.\n\nIf you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.\n\nNever use someone else's code, read the tutorials or communicate with other person during a virtual contest.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"/contest/387/virtual\" method=\"get\">\r\n <input type=\"submit\" name=\"submit\" value=\"Start virtual contest\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div>\r\n</div>\r\n <script>\r\n $(function () {\r\n $(\".ContestVirtualFrame .sidebar-caption-icon\").click(function() {\r\n $(this).toggleClass(\"la-angle-down la-angle-right\");\r\n const $target = $(this).parent().next();\r\n $target.toggle();\r\n const dataPageUrl = $target.attr(\"data-page-url\");\r\n const collapsed = $(this).hasClass(\"la-angle-right\");\r\n const params = {\r\n action: \"setCollapsed\",\r\n sidebarFrameSimpleClassName: \"ContestVirtualFrame\",\r\n collapsed\r\n };\r\n $.each($target[0].attributes, function(i, a) {\r\n const name = a.name;\r\n if (name.startsWith(\"data-extra-key-\")) {\r\n const key = a.value;\r\n const keyIndex = parseInt(name.substring(\"data-extra-key-\".length));\r\n const value = $target.attr(\"data-extra-value-\" + keyIndex);\r\n params[key] = value;\r\n }\r\n });\r\n $.post(dataPageUrl, params, function (result) {\r\n if (result[\"success\"] !== \"true\") {\r\n Codeforces.showMessage(\"Failed to save collapsed state.\");\r\n }\r\n }, \"json\");\r\n return false;\r\n });\r\n })\r\n </script>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Problem tags\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Binary search\">\r\n binary search\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Heaps, binary search trees, segment trees, hash tables, etc\">\r\n data structures\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Difficulty\">\r\n *2200\r\n</span>\r\n </div>\n <div style=\"clear:both;text-align:right;font-size:1.1rem;\">\r\n <span title=\"Please login into the Codeforces\" class=\"notice\">No tag edit access</span>\r\n </div>\r\n</div>\r\n </div>\n\r\n<form id=\"addTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='09bc46bb5d4d207e3531621f04accde5'/>\r\n <input name=\"action\" type=\"hidden\" value=\"addTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"6210\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<form id=\"removeTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='09bc46bb5d4d207e3531621f04accde5'/>\r\n <input name=\"action\" type=\"hidden\" value=\"removeTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"6210\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<script type=\"text/javascript\">\r\n $(\".tag-box img\").click(function () {\r\n var tagName = $(this).attr(\"value\");\r\n Codeforces.confirm(\"Are you sure you want to remove this tag?\", function () {\r\n $(\"#removeTagForm input[name=tagName]\").val(tagName);\r\n $(\"#removeTagForm\").submit();\r\n }, function () {\r\n }, \"Yes\", \"No\");\r\n });\r\n\r\n $(\"#addTagLink\").click(function () {\r\n $(this).hide();\r\n $(\"#addTagLabel\").show();\r\n return false;\r\n });\r\n\r\n $(\"#addTagSelect\").change(function () {\r\n var tagName = $(this).val();\r\n if (tagName === \"\") {\r\n $(\"#addTagLabel\").hide();\r\n $(\"#addTagLink\").show();\r\n } else {\r\n $(\"#addTagForm input[name=tagName]\").val(tagName);\r\n $(\"#addTagForm\").submit();\r\n }\r\n });\r\n</script>\r\n\r\n<style type=\"text/css\">\r\n#new-resource-form tr td {\r\npadding-top: 0.5em;\r\n}\r\n#new-resource-form input:not([type=\"submit\"]) {\r\nfont-size: 0.8em;\r\n}\r\n#new-resource-form select {\r\nfont-size: 0.8em;\r\n}\r\n.new-resource-error {\r\nfont-size: 0.8em;\r\n}\r\n.resource-locale {\r\ncolor: #666;\r\nfont-family: Consolas, \"Andale Mono WT\", \"Andale Mono\", \"Lucida Console\", \"Lucida Sans Typewriter\", \"DejaVu Sans Mono\", \"Bitstream Vera Sans Mono\", \"Liberation Mono\", \"Nimbus Mono L\", Monaco, \"Courier New\", Courier, monospace;\r\n}\r\n</style>\r\n<div class=\"roundbox sidebox sidebar-menu borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Contest materials\n<div class=\"top-links\">\n</div>\n</div>\n<ul>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/10569\" title=\"Codeforces Round #227 (Div. 2)\" target=\"_blank\">Announcement</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"2176:2182\" resourceName=\"Announcement\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/10583\" title=\"Editorial Codeforces Round #227 (Div. 2)\" target=\"_blank\">Tutorial</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"2177:2183\" resourceName=\"Tutorial\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n</ul>\r\n</div></div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li class=\"current selectedLava\"><a\r\n href=\"/contest/387\">Problems</a></li>\r\n <li><a\r\n href=\"/contest/387/submit\">Submit Code</a></li>\r\n <li><a\r\n href=\"/contest/387/my\">My Submissions</a></li>\r\n <li><a\r\n href=\"/contest/387/status\">Status</a></li>\r\n <li><a\r\n href=\"/contest/387/hacks\">Hacks</a></li>\r\n <li><a\r\n href=\"/contest/387/room/1\">Room</a></li>\r\n <li><a\r\n href=\"/contest/387/standings\">Standings</a></li>\r\n <li><a\r\n href=\"/contest/387/customtest\">Custom Invocation</a></li>\r\n</ul>\r\n</div>\n\r\n <style>\r\n #facebox .content:has(.diff-popup) {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n }\r\n\r\n .testCaseMarker {\r\n position: absolute;\r\n font-weight: bold;\r\n font-size: 1rem;\r\n }\r\n\r\n .diff-popup {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n display: none;\r\n overflow: auto;\r\n }\r\n\r\n .input-output-copier {\r\n font-size: 1.2rem;\r\n float: right;\r\n color: #888 !important;\r\n cursor: pointer;\r\n border: 1px solid rgb(185, 185, 185);\r\n padding: 3px;\r\n margin: 1px;\r\n line-height: 1.1rem;\r\n text-transform: none;\r\n }\r\n\r\n .input-output-copier:hover {\r\n background-color: #def;\r\n }\r\n\r\n .test-explanation textarea {\r\n width: 100%;\r\n height: 1.5em;\r\n }\r\n\r\n .pending-submission-message {\r\n color: darkorange !important;\r\n }\r\n </style>\r\n <script>\r\n const OPENING_SPACE = String.fromCharCode(1001);\r\n const CLOSING_SPACE = String.fromCharCode(1002);\r\n\r\n const nodeToText = function (node, pre) {\r\n let result = [];\r\n\r\n if (node.tagName === \"SCRIPT\" || node.tagName === \"math\"\r\n || (node.classList && node.classList.contains(\"input-output-copier\")))\r\n return [];\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(OPENING_SPACE);\r\n }\r\n\r\n if (node.nodeType === Node.TEXT_NODE) {\r\n let s = node.textContent;\r\n if (!pre) {\r\n s = s.replace(/\\s+/g, \" \");\r\n }\r\n if (s.length > 0) {\r\n result.push(s);\r\n }\r\n }\r\n\r\n if (pre && node.tagName === \"BR\") {\r\n result.push(\"\\n\");\r\n }\r\n\r\n node.childNodes.forEach(function (child) {\r\n result.push(nodeToText(child, node.tagName === \"PRE\").join(\"\"));\r\n });\r\n\r\n if (node.tagName === \"DIV\"\r\n || node.tagName === \"P\"\r\n || node.tagName === \"PRE\"\r\n || node.tagName === \"UL\"\r\n || node.tagName === \"LI\"\r\n ) {\r\n result.push(\"\\n\");\r\n }\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(CLOSING_SPACE);\r\n }\r\n\r\n return result;\r\n }\r\n\r\n const isSpecial = function (c) {\r\n return c === ',' || c === '.' || c === ';' || c === ')' || c === ' ';\r\n }\r\n\r\n const convertStatementToText = function(statmentNode) {\r\n const text = nodeToText(statmentNode, false).join(\"\").replace(/ +/g, \" \").replace(/\\n\\n+/g, \"\\n\\n\");\r\n let result = [];\r\n for (let i = 0; i < text.length; i++) {\r\n const c = text.charAt(i);\r\n if (c === OPENING_SPACE) {\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"E\" data-uuid=\"ps_65fa7fe034e38b7d2dbe99130d2486b9264a2388\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">E. George and Cards</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>George is a cat, so he loves playing very much.</p><p>Vitaly put <span class=\"tex-span\"><i>n</i></span> cards in a row in front of George. Each card has one integer written on it. All cards had distinct numbers written on them. Let's number the cards from the left to the right with integers from <span class=\"tex-span\">1</span> to <span class=\"tex-span\"><i>n</i></span>. Then the <span class=\"tex-span\"><i>i</i></span>-th card from the left contains number <span class=\"tex-span\"><i>p</i><sub class=\"lower-index\"><i>i</i></sub></span> (<span class=\"tex-span\">1 ≤ <i>p</i><sub class=\"lower-index\"><i>i</i></sub> ≤ <i>n</i></span>). </p><p>Vitaly wants the row to have exactly <span class=\"tex-span\"><i>k</i></span> cards left. He also wants the <span class=\"tex-span\"><i>i</i></span>-th card from left to have number <span class=\"tex-span\"><i>b</i><sub class=\"lower-index\"><i>i</i></sub></span> written on it. Vitaly gave a task to George, to get the required sequence of cards using the remove operation <span class=\"tex-span\"><i>n</i> - <i>k</i></span> times.</p><p>In one <span class=\"tex-font-style-it\">remove operation</span> George can choose <span class=\"tex-span\"><i>w</i></span> (<span class=\"tex-span\">1 ≤ <i>w</i></span>; <span class=\"tex-span\"><i>w</i></span> is not greater than the current number of cards in the row) contiguous cards (contiguous subsegment of cards). Let's denote the numbers written on these card as <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">1</sub>, <i>x</i><sub class=\"lower-index\">2</sub>, ..., <i>x</i><sub class=\"lower-index\"><i>w</i></sub></span> (from the left to the right). After that, George can remove the card <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span>, such that <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub> ≤ <i>x</i><sub class=\"lower-index\"><i>j</i></sub></span> for each <span class=\"tex-span\"><i>j</i></span> <span class=\"tex-span\">(1 ≤ <i>j</i> ≤ <i>w</i>)</span>. After the described operation George gets <span class=\"tex-span\"><i>w</i></span> pieces of sausage.</p><p>George wondered: what maximum number of pieces of sausage will he get in total if he reaches his goal and acts optimally well? Help George, find an answer to his question!</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains integers <span class=\"tex-span\"><i>n</i></span> and <span class=\"tex-span\"><i>k</i></span> (<span class=\"tex-span\">1 ≤ <i>k</i> ≤ <i>n</i> ≤ 10<sup class=\"upper-index\">6</sup></span>) — the initial and the final number of cards.</p><p>The second line contains <span class=\"tex-span\"><i>n</i></span> distinct space-separated integers <span class=\"tex-span\"><i>p</i><sub class=\"lower-index\">1</sub>, <i>p</i><sub class=\"lower-index\">2</sub>, ..., <i>p</i><sub class=\"lower-index\"><i>n</i></sub></span> (<span class=\"tex-span\">1 ≤ <i>p</i><sub class=\"lower-index\"><i>i</i></sub> ≤ <i>n</i></span>) — the initial row of cards. </p><p>The third line contains <span class=\"tex-span\"><i>k</i></span> space-separated integers <span class=\"tex-span\"><i>b</i><sub class=\"lower-index\">1</sub>, <i>b</i><sub class=\"lower-index\">2</sub>, ..., <i>b</i><sub class=\"lower-index\"><i>k</i></sub></span> — the row of cards that you need to get. It is guaranteed that it's possible to obtain the given row by using the remove operation for <span class=\"tex-span\"><i>n</i> - <i>k</i></span> times.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print a single integer — the maximum number of pieces of sausage that George can get if he acts optimally well.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>3 2<br />2 1 3<br />1 3<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>10 5<br />1 2 3 4 5 6 7 8 9 10<br />2 4 6 8 10<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>30<br /></pre></div></div></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=E]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== statementText) {\r\n $problem.find(\".diff-notifier\").show();\r\n\r\n $problem.find(\".diff-notifier-close\").click(function() {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n $problem.find(\".diff-notifier\").hide();\r\n });\r\n\r\n $problem.find(\"a.view-changes\").click(function() {\r\n $.post(\"/data/diff\", {action: \"getDiff\", a: previousStatementText, b: statementText}, function (result) {\r\n if (result[\"success\"] === \"true\") {\r\n Codeforces.facebox(\".diff-popup\", \"//codeforces.org/s/73366\");\r\n $(\"#facebox .diff-popup\").html(result[\"diff\"]);\r\n }\r\n }, \"json\");\r\n });\r\n }\r\n } else {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n }\r\n });\r\n });\r\n </script>\r\n\r\n\r\n<script type=\"text/javascript\">\r\n $(document).ready(function () {\r\n window.changedTests = new Set();\r\n\r\n function endsWith(string, suffix) {\r\n return string.indexOf(suffix, string.length - suffix.length) !== -1;\r\n }\r\n\r\n const inputFileDiv = $(\"div.input-file\");\r\n const inputFile = inputFileDiv.text();\r\n const outputFileDiv = $(\"div.output-file\");\r\n const outputFile = outputFileDiv.text();\r\n\r\n\r\n if (!endsWith(inputFile, \"standard input\")\r\n && !endsWith(inputFile, \"standard input\")) {\r\n inputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n if (!endsWith(outputFile, \"standard output\")\r\n && !endsWith(outputFile, \"standard output\")) {\r\n outputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n const titleDiv = $(\"div.header div.title\");\r\n\r\n\r\n\r\n String.prototype.replaceAll = function (search, replace) {\r\n return this.split(search).join(replace);\r\n };\r\n\r\n $(\".sample-test .title\").each(function () {\r\n const preId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n const cpyId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n\r\n $(this).parent().find(\"pre\").attr(\"id\", preId);\r\n const $copy = $(\"<div title='Copy' data-clipboard-target='#\" + preId + \"' id='\" + cpyId + \"' class='input-output-copier'>Copy</div>\");\r\n $(this).append($copy);\r\n\r\n const clipboard = new Clipboard('#' + cpyId, {\r\n text: function (trigger) {\r\n const pre = document.querySelector('#' + preId);\r\n const lines = pre.querySelectorAll(\".test-example-line\");\r\n return Codeforces.filterClipboardText(pre.innerText, lines.length);\r\n }\r\n });\r\n\r\n const isInput = $(this).parent().hasClass(\"input\");\r\n\r\n clipboard.on('success', function (e) {\r\n if (isInput) {\r\n Codeforces.showMessage(\"The example input has been copied into the clipboard\");\r\n } else {\r\n Codeforces.showMessage(\"The example output has been copied into the clipboard\");\r\n }\r\n e.clearSelection();\r\n });\r\n });\r\n\r\n $(\".test-form-item input\").change(function () {\r\n addPendingSubmissionMessage($($(this).closest(\"form\")), \"You changed the answer, do not forget to submit it if you want to save the changes\");\r\n const index = $(this).closest(\".problemindexholder\").attr(\"problemindex\");\r\n let test = \"\";\r\n $(this).closest(\"form input\").each(function () {\r\n const test_ = $(this).attr(\"name\");\r\n if (test_ && test_.substring(0, 4) === \"test\") {\r\n test = test_;\r\n }\r\n });\r\n if (index.length > 0 && test.length > 0) {\r\n const indexTest = index + \"::\" + test;\r\n window.changedTests.add(indexTest);\r\n }\r\n });\r\n\r\n $(window).on('beforeunload', function () {\r\n if (window.changedTests.size > 0) {\r\n return 'Dialog text here';\r\n }\r\n });\r\n\r\n autosize($('.test-explanation textarea'));\r\n\r\n $(\".test-example-line\").hover(function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n let top = 1E20;\r\n let left = 1E20;\r\n let problem = $(this).closest(\".problemindexholder\");\r\n $(this).closest(\".input\").find(\".\" + clazz).css(\"background-color\", \"#FFFDE7\").each(function() {\r\n top = Math.min(top, $(this).offset().top);\r\n left = Math.min(left, $(this).offset().left);\r\n });\r\n let testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n if (testCaseMarker.length === 0) {\r\n const html = \"<div class=\\\"testCaseMarker testCaseMarker_\" + end + \" notice\\\"></div>\";\r\n problem.append($(html));\r\n testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n }\r\n if (testCaseMarker) {\r\n testCaseMarker.show()\r\n .offset({top, left: left - 20})\r\n .text(end);\r\n }\r\n }\r\n }\r\n });\r\n }, function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n $(\".\" + clazz).css(\"background-color\", \"\");\r\n $(this).closest(\".problemindexholder\").find(\".testCaseMarker_\" + end).hide();\r\n }\r\n }\r\n });\r\n });\r\n\r\n });\r\n</script>\r\n\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 05:38:28</span> (j3).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/73366/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/73366/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/73366/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/73366/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-73366.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'8122c4a2fe36164b',t:'MTY5NjY0NjMwOC40MDcwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"},"long_tags":{"kind":"string","value":"[\"Binary search\", \"Heaps, binary search trees, segment trees, hash tables, etc\"]"},"short_tags":{"kind":"string","value":"[\"binary search\", \"data structures\", \"*2200\"]"},"tutorial_link":{"kind":"string","value":"https://codeforces.com/blog/entry/10583"},"tutorial_page":{"kind":"string","value":"\r\n\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"36a5cb4572cb122db333ec3b9f88364a\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"h1\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Editorial Codeforces Round #227 (Div. 2) - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n \n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Editorial Codeforces Round #227 (Div. 2) - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/81027/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/81027/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/81027/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/81027/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/81027/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/81027/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/81027/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/81027/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/81027/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/81027/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/81027/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/81027/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/81027/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/81027/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/573cedc6b04c15481941f418269f4057/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='36a5cb4572cb122db333ec3b9f88364a'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/81027/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fblog%2Fentry%2F10583\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='36a5cb4572cb122db333ec3b9f88364a'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Pay attention\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n <div style=\"text-align:center;border-bottom: 1px solid rgb(185, 185, 185);margin:0 -0.5em 0.5em -0.5em;padding: 0 1em 0.5em 1em;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 1, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:51:56</span><br/><a href=\"/contestRegistration/1876\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n <div style=\"text-align:center;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 2, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:51:56</span><br/><a href=\"/contestRegistration/1877\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n\r\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div>\r\n\r\n\n <div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\n\r\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='36a5cb4572cb122db333ec3b9f88364a'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n </label>\r\n </div>\r\n <div style=\"padding: 0 1em 1em 1em;text-align:right;\">\r\n <input style=\"height:1.65em;padding:0 0.75em;\" type=\"submit\" value=\"Find\"/>\r\n </div>\r\n </form>\r\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".handleBox\").autocomplete(\"/data/handles\", {\r\n delay: 200,\r\n width: 200,\r\n selectFirst: false,\r\n matchContains: true,\r\n minChars: 3\r\n });\r\n $(\".handleForm\").attr(\"autocomplete\", \"off\").submit(function () {\r\n var link = \"/profile/userHandle\".replace(\r\n \"userHandle\", $(this).find(\".handleBox\").val()\r\n );\r\n window.location = link;\r\n return false;\r\n });\r\n });\n </script>\n\r\n\r\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Recent actions\n <div class=\"top-links\">\n </div>\n </div>\n <div class=\"recent-actions\">\r\n <ul>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/121073\">Meta Hacker Cup 2023 Round 1</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/.Danet\" title=\"Expert .Danet\" class=\"rated-user user-blue\">.Danet</a> →\r\n <a href=\"/blog/entry/121172\">[TLE on pretest1]</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\" class=\"rated-user user-red\">Pyqe</a> →\r\n <a href=\"/blog/entry/121025\">Codeforces Round #902 (Div. 1, Div. 2, based on COMPFEST 15 — Final Round)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pranshu_Pandya\" title=\"Specialist Pranshu_Pandya\" class=\"rated-user user-cyan\">Pranshu_Pandya</a> →\r\n <a href=\"/blog/entry/121171\">An Interesting Tree Problem</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/sszcdjr\" title=\"Master sszcdjr\" class=\"rated-user user-orange\">sszcdjr</a> →\r\n <a href=\"/blog/entry/119859\">Codeforces Round 896 (Div. 1, Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/119880\">It's Happening! Meta Hacker Cup 2023 Schedule</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/DaviddeGea1\" title=\"Expert DaviddeGea1\" class=\"rated-user user-blue\">DaviddeGea1</a> →\r\n <a href=\"/blog/entry/70917\">Number of ways of dividing an array into 2 parts such that sum of each part is > k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bekh\" title=\"Master Bekh\" class=\"rated-user user-orange\">Bekh</a> →\r\n <a href=\"/blog/entry/74245\">Questions and doubts regarding Aliens DP trick</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a> →\r\n <a href=\"/blog/entry/8192\">Codeforces Round #190 — Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/hocky\" title=\"Candidate Master hocky\" class=\"rated-user user-violet\">hocky</a> →\r\n <a href=\"/blog/entry/95323\">FBHC wuining uw Day? Incwease uw stacc size! (ㅅ´ ˘ `)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/liouzhou_101\" title=\"International Master liouzhou_101\" class=\"rated-user user-orange\">liouzhou_101</a> →\r\n <a href=\"/blog/entry/87598\">Editorial of Codeforces Round #700</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/yeon_gist\" title=\"Newbie yeon_gist\" class=\"rated-user user-gray\">yeon_gist</a> →\r\n <a href=\"/blog/entry/121170\">plusMinusPermutation computing error</a>\r\n <img alt=\"Text created or updated\" title=\"Text created or updated\" src=\"//codeforces.org/s/81027/images/icons/x-update-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/altforminuscontribution\" title=\"Newbie altforminuscontribution\" class=\"rated-user user-gray\">altforminuscontribution</a> →\r\n <a href=\"/blog/entry/121162\">My screen get unexpectedly big, what should I do</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/atcoder_official\" title=\"Unrated, atcoder_official\" class=\"rated-user user-black\">atcoder_official</a> →\r\n <a href=\"/blog/entry/121120\">We will hold UNIQUE VISION Programming Contest 2023 Autumn(AtCoder Beginner Contest 323)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/YouStill_DontKnowMeYet\" title=\"Candidate Master YouStill_DontKnowMeYet\" class=\"rated-user user-violet\">YouStill_DontKnowMeYet</a> →\r\n <a href=\"/blog/entry/117659\">[GYM] Al-Baath Collegiate Programming Contest 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/ankancool\" title=\"Expert ankancool\" class=\"rated-user user-blue\">ankancool</a> →\r\n <a href=\"/blog/entry/121136\">Invitation to AstroByte 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/GeZhiyuan\" title=\"Grandmaster GeZhiyuan\" class=\"rated-user user-red\">GeZhiyuan</a> →\r\n <a href=\"/blog/entry/120943\">Codeforces Round 901 (Div. 1, Div. 2) Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a> →\r\n <a href=\"/blog/entry/120772\">PSA: Increase your stack size before the Meta Hacker Cup, here's how</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/dino_merlin\" title=\"Expert dino_merlin\" class=\"rated-user user-blue\">dino_merlin</a> →\r\n <a href=\"/blog/entry/121145\">Intuitive approach for CEOI Kangaroo?</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/icecuber\" title=\"Grandmaster icecuber\" class=\"rated-user user-red\">icecuber</a> →\r\n <a href=\"/blog/entry/70018\">CSES DP section editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bn00b\" title=\"Newbie Bn00b\" class=\"rated-user user-gray\">Bn00b</a> →\r\n <a href=\"/blog/entry/98820\">[FEATURE REQUEST : ATCODER] TOPICS TAGS AND SORTING BY SOLVE COUNT</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a> →\r\n <a href=\"/blog/entry/121163\">AtCoder Regular Contest 166 Announcement</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/windva\" title=\"Grandmaster windva\" class=\"rated-user user-red\">windva</a> →\r\n <a href=\"/blog/entry/120644\">Codeforces Round 899 (Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Misa-Misa\" title=\"Expert Misa-Misa\" class=\"rated-user user-blue\">Misa-Misa</a> →\r\n <a href=\"/blog/entry/121157\">Someone please help me understand this.</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/shivam565\" title=\"Specialist shivam565\" class=\"rated-user user-cyan\">shivam565</a> →\r\n <a href=\"/blog/entry/108348\">Total number of subarrays with sum atmost k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n </ul>\r\n </div>\r\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/recent-actions\">Detailed →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n</div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li><a\r\n href=\"/profile/gridnevvvit\">gridnevvvit</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/gridnevvvit\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/gridnevvvit\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/gridnevvvit\">Submissions</a></li>\r\n <li><a\r\n href=\"/groups/with/gridnevvvit\">Groups</a></li>\r\n <li><a\r\n href=\"/contests/with/gridnevvvit\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/gridnevvvit\">Problemsetting</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/gridnevvvit\" style=\"text-decoration:none;color:black !important;\">gridnevvvit's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"10638\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/10583\"> <p>Editorial Codeforces Round #227 (Div. 2)</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/gridnevvvit\" title=\"Candidate Master gridnevvvit\" class=\"rated-user user-violet\">gridnevvvit</a>,\r\n <span class=\"format-humantime\" title=\"Jan/30/2014 22:21\">10 years ago</span>,\r\n translation,\r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><h3><a href=\"/contest/387/problem/A\" title=\"Codeforces Round 227 (Div. 2)\">387A - George and Sleep</a></h3><p>I will describe the simple solution. Let George woke up in the <span class=\"tex-span\"><i>h</i><sub class=\"lower-index\">0</sub></span> hours and <span class=\"tex-span\"><i>m</i><sub class=\"lower-index\">0</sub></span> minutes, and he slept for <span class=\"tex-span\"><i>h</i><sub class=\"lower-index\">1</sub></span> hours and <span class=\"tex-span\"><i>m</i><sub class=\"lower-index\">1</sub></span> minutes. Let's get the number <span class=\"tex-span\"><i>h</i><sub class=\"lower-index\"><i>p</i></sub> = <i>h</i><sub class=\"lower-index\">0</sub> - <i>h</i><sub class=\"lower-index\">1</sub></span> and <span class=\"tex-span\"><i>m</i><sub class=\"lower-index\"><i>p</i></sub> = <i>m</i><sub class=\"lower-index\">0</sub> - <i>m</i><sub class=\"lower-index\">1</sub></span>. If <span class=\"tex-span\"><i>m</i><sub class=\"lower-index\"><i>p</i></sub> < 0</span>, then you should add to <span class=\"tex-span\"><i>m</i><sub class=\"lower-index\"><i>p</i></sub></span> <span class=\"tex-span\">60</span> minutes and subtract from <span class=\"tex-span\"><i>h</i><sub class=\"lower-index\"><i>p</i></sub></span> one hour. After that if <span class=\"tex-span\"><i>h</i><sub class=\"lower-index\"><i>p</i></sub> < 0</span>, then add to it <span class=\"tex-span\">24</span> hours. You can print the answer in C++ by using the following line:</p> <pre><code>printf("%02d:%02d", h[p], m[p]).\n</code></pre><p>The complexity is <span class=\"tex-span\"><i>O</i>(1)</span> time and <span class=\"tex-span\"><i>O</i>(1)</span> memory.</p><p>Author's solution: <a href=\"/contest/387/submission/5850831\" title=\"Submission 5850831 by gridnevvvit\">5850831</a></p><h3><a href=\"/contest/387/problem/B\" title=\"Codeforces Round 227 (Div. 2)\">387B - George and Round</a></h3><p>Consider the number of requirements of the difficulties, which we will cover, and we will come up with and prepare new problem to cover other requirements. It is clear that if we decided to meet the <span class=\"tex-span\"><i>i</i></span> out of <span class=\"tex-span\"><i>n</i></span> requirements, it would be better to take those with minimal complexity. Let's simplify <span class=\"tex-span\"><i>i</i></span> most difficult problems to lightest requirements. If all goes well, then we update the answer by value <span class=\"tex-span\"><i>n</i> - <i>i</i></span>.</p><p>The complexity is: <span class=\"tex-span\"><i>O</i>(<i>n</i><sup class=\"upper-index\">2</sup>)</span> time / <span class=\"tex-span\"><i>O</i>(<i>n</i>)</span> memory. Note, that there is an solution with complexity <span class=\"tex-span\"><i>O</i>(<i>n</i> + <i>m</i>)</span>.</p><p>Author's solution: <a href=\"/contest/387/submission/5850888\" title=\"Submission 5850888 by gridnevvvit\">5850888</a></p><h3><a href=\"/contest/387/problem/C\" title=\"Codeforces Round 227 (Div. 2)\">387C - George and Number</a></h3><p>Let's obtain the following irreducible representation of a number <span class=\"tex-span\"><i>p</i> = <i>a</i><sub class=\"lower-index\">1</sub> + <i>a</i><sub class=\"lower-index\">2</sub> + ... + <i>a</i><sub class=\"lower-index\"><i>k</i></sub></span>, where <span class=\"tex-span\"> + </span> is a concatenation, and numbers <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> have the form <span class=\"tex-span\"><i>x</i>00..000</span> (x — is non zero digit, and after that there are only zeroes). Let's determine largest index <span class=\"tex-span\"><i>i</i></span>, such that <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub> + <i>a</i><sub class=\"lower-index\">2</sub> + ... + <i>a</i><sub class=\"lower-index\"><i>i</i> - 1</sub> < <i>a</i><sub class=\"lower-index\"><i>i</i></sub></span>. If there are no such index <span class=\"tex-span\"><i>i</i></span> then <span class=\"tex-span\"><i>i</i> = 1</span>. After that is <span class=\"tex-span\"><i>k</i> - <i>i</i> + 1</span>. You can compare numbers by using length of number and first digit. You can prove these solution as home task : )</p><p>The complexity is: <span class=\"tex-span\"><i>O</i>(<i>n</i>)</span> time / <span class=\"tex-span\"><i>O</i>(<i>n</i>)</span> memory.</p><p>Author's solution: <a href=\"/contest/387/submission/5850919\" title=\"Submission 5850919 by gridnevvvit\">5850919</a></p><h3><a href=\"/contest/387/problem/D\" title=\"Codeforces Round 227 (Div. 2)\">387D - George and Interesting Graph</a></h3><p>To solve this problem you should know about bipartite matching.</p><p>Let's consider the center of graph <span class=\"tex-span\"><i>i</i></span>. After that let's remove arcs that have form <span class=\"tex-span\">(<i>i</i>, <i>u</i>)</span> or <span class=\"tex-span\">(<i>u</i>, <i>i</i>)</span>. Let's there are <span class=\"tex-span\"><i>cntWithI</i></span> arcs of such type. Let's <span class=\"tex-span\"><i>Other</i> = <i>m</i> - <i>CntWithI</i></span> — number of other arcs.</p><p>After that we should found maximal bipartite matching on the bipartite graph. This graph has following idea: left part of this graph is indegrees of all vertexes except vertex <span class=\"tex-span\"><i>i</i></span>, right part of this graph is outdegrees of all vertexes except vertex <span class=\"tex-span\"><i>i</i></span>. Also if there an arc <span class=\"tex-span\">(<i>i</i>, <i>j</i>)</span> in our graph then in our bipartite graph there an arc <span class=\"tex-span\">(<i>i</i>, <i>j</i>)</span>, where <span class=\"tex-span\"><i>i</i></span> — vertex from left part, <span class=\"tex-span\"><i>j</i></span> — vertex from the right part. Let's size of bipartite matching on the bipartite graph equals to <span class=\"tex-span\"><i>leng</i></span>. Then answer for the current vertex <span class=\"tex-span\"><i>i</i></span> equals to <span class=\"tex-span\">2<i>n</i> - 1 - <i>cntWithI</i> + <i>Other</i> - <i>leng</i> + (<i>n</i> - 1) - <i>leng</i></span>. After that you should update global answer. Why it is correct? It is simple to understand that if we will found bipartite matching on the bipartite graph we will cover maximal number of requirements on in/out degrees. Because of that, we will remove all other arcs, except of maximal matching, and after that we will add this maximal matching to full matching by adding <span class=\"tex-span\">(<i>n</i> - 1) - <i>leng</i></span> arcs. Note, it is important, that self-loops are not forbidden. Withoud self-loops problem is very hard, I think. </p><p>The complexity is: <span class=\"tex-span\"><i>O</i>(<i>n</i><sup class=\"upper-index\">2</sup><i>m</i>)</span> time / <span class=\"tex-span\"><i>O</i>(<i>n</i> + <i>m</i>)</span> memory.</p><p><a href=\"/contest/387/submission/5850946\" title=\"Submission 5850946 by gridnevvvit\">5850946</a></p><h3><a href=\"/contest/387/problem/E\" title=\"Codeforces Round 227 (Div. 2)\">387E - George and Cards</a></h3><p>Let's calculate arrays <span class=\"tex-span\"><i>pos</i>[<i>i</i>]</span> — position of number <span class=\"tex-span\"><i>i</i></span> in permutation <span class=\"tex-span\"><i>p</i></span> and <span class=\"tex-span\"><i>need</i>[<i>i</i>]</span> — equals to one if we should remove number <span class=\"tex-span\"><i>i</i></span> from permutation <span class=\"tex-span\"><i>p</i></span>, and zero if we shouldn't remove <span class=\"tex-span\"><i>i</i></span> from permutation <span class=\"tex-span\"><i>p</i></span>. </p><p>Let's <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub>, <i>a</i><sub class=\"lower-index\">2</sub>, ..., <i>a</i><sub class=\"lower-index\"><i>n</i> - <i>k</i></sub></span> — numvers, which we should remove. It is clear to understand that we should remove these number in increasing order. It is simple to proof this statement.</p><p>Let's iterate <span class=\"tex-span\"><i>i</i></span> from to <span class=\"tex-span\">1</span> to <span class=\"tex-span\"><i>n</i></span>. Also we the current number we will have special set (set <>in с++, TreeSet in Java) of positions of non-erased numbers (which are smaller then <span class=\"tex-span\"><i>i</i></span>) of permutation. These position can create an ``obstacle'' for current position of number <span class=\"tex-span\"><i>i</i></span>. It is simple to support this special set. Also we can add to this set numbers <span class=\"tex-span\"> - 1</span> and <span class=\"tex-span\"><i>n</i></span>. Now it is easy to find length og the maximal sub-array, where current number is a minimum. You can prosess such query by using standart functions of programming language (lower and higher in Java). After that we should use Fenwick tree to determine quantity of numbers which are not removed on the maximal sub-array.</p><p>The complexity is: <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/5e7dae7c1838af7ba7570bdf02ff61029b043be6.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> time / <span class=\"tex-span\"><i>O</i>(<i>n</i>)</span> memory.</p><p>Very simple implementation on Java: <a href=\"/contest/387/submission/5850986\" title=\"Submission 5850986 by gridnevvvit\">5850986</a></p></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/387\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 227 (Div. 2)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-6883-10638\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"6883\",\n blogEntryId: \"10583\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n <div style=\"font-size: 1.1rem;line-height: 11px;\">\r\n <img style=\"vertical-align: middle;\" src=\"//codeforces.org/s/81027/images/blog/tags.png\" title=\"Tags\" alt=\"Tags\"/>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=editorial\" class=\"tag notice\" style=\"text-decoration: none;\">editorial</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=codeforces\" class=\"tag notice\" style=\"text-decoration: none;\">codeforces</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=round\" class=\"tag notice\" style=\"text-decoration: none;\">round</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=227\" class=\"tag notice\" style=\"text-decoration: none;\">227</a>\r\n </span>\r\n </div>\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-10638\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+35</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-10638\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/gridnevvvit\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/gridnevvvit\">\n gridnevvvit\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Jan/30/2014 22:21\">10 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/10583#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/10583#comments\">\n 25\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"10654\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (25)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159495\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/coolbun\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/coolbun\" title=\"Candidate Master coolbun\" class=\"rated-user user-violet\">coolbun</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/30/2014 22:54\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159495\" href=\"?#comment-159495\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159495\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"2\"\r\n data-commentUserId=\"90437\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+2</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159495\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can anyone explain the solution of problem C</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159495 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159495 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159495\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159552\" commentParentId=\"159495\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/prakhar3agrwal\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/45384/avatar/63c5e4d25f17da6b.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/prakhar3agrwal\" title=\"Expert prakhar3agrwal\" class=\"rated-user user-blue\">prakhar3agrwal</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/31/2014 14:13\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159552\" href=\"?#comment-159552\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159495\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159552\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"45384\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159552\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Well my approach to this question was different , just start from the beginning and take 2 string variables. Let the variables be g and l (for global and local resp.),now g will store the substring starting from the beginning till just before the index from where l started.Now if the next character is '0' then we are bound to include it in the local string otherwise just see that whether g>=l or not , if yes then increase ans by 1 and include l in g (g+=l) and clear l, else make ans=1, g=g+l and clear l. This is because if g<l then obviously the substring in l should occur before g in resultant substring (meaning it will be "lg" instead of "gl"). Finally print the ans........</p><p>Hope it helps.... </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159552 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159552 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159552\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159577\" commentParentId=\"159552\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/eddycael\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/52186/avatar/a0efb238d6a68050.jpg'/> </a>\n <div><a href=\"/profile/eddycael\" title=\"Specialist eddycael\" class=\"rated-user user-cyan\">eddycael</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/31/2014 20:53\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159577\" href=\"?#comment-159577\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159552\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159577\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"52186\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159577\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Hello, (sorry for my poor english) My solution traverses the string with 2 pointers and whenever it encounters a string representing a smaller number than what's left then add 1 to the answer. It is not necessary to generate any substrings... Just analyze the representation of strings of equal length. Here's my solution: <a href=\"//codeforces.com/contest/387/submission/5858084\">solutionECMC</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159577 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159577 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159577\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159740\" commentParentId=\"159577\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/prakhar3agrwal\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/45384/avatar/63c5e4d25f17da6b.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/prakhar3agrwal\" title=\"Expert prakhar3agrwal\" class=\"rated-user user-blue\">prakhar3agrwal</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2014 08:26\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159740\" href=\"?#comment-159740\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159577\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159740\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"45384\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159740\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I am not generating any substring as such , it was the concept used in my solution, my time complexity is O(n).</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159740 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159740 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159740\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159553\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/jibon_ebong_shomoy\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/107227/avatar/d1546e81b26787b3.jpg'/> </a>\n <div><a href=\"/profile/jibon_ebong_shomoy\" title=\"Specialist jibon_ebong_shomoy\" class=\"rated-user user-cyan\">jibon_ebong_shomoy</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/31/2014 14:52\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159553\" href=\"?#comment-159553\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"159553\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"159553\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"107227\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159553\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I don't understand the solution of D . can anyone explain? what to do? why the last part of answer <code>(n-1)-leng</code> for?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159553 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159553 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159553\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159566\" commentParentId=\"159553\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/gridnevvvit\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/31163/avatar/db500a30a0b0a6f1.jpg'/> </a>\n <div><a href=\"/profile/gridnevvvit\" title=\"Candidate Master gridnevvvit\" class=\"rated-user user-violet\">gridnevvvit</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/31/2014 17:12\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159566\" href=\"?#comment-159566\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159553\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159566\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"31163\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159566\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>We will add some arcs to create prefect matching in graph</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159566 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159566 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159566\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"335415\" commentParentId=\"159553\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/u33how\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/216525/avatar/a0f0155335a1dd88.jpg'/> </a>\n <div><a href=\"/profile/u33how\" title=\"Expert u33how\" class=\"rated-user user-blue\">u33how</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/04/2017 17:52\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-335415\" href=\"?#comment-335415\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159553\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"335415\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"216525\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-335415\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I think the equation came from these :</p><p>ans = 2*(n-1); // for adding the (u,i)and(i,u) edges</p><p>ans = ans — (cntWithI) ; // they were already given, so we do not need to delete them,</p><p>ans = ans+1 ; // the center must have a self loop according to problem description.</p><p>ans = ans + Others ; // delete all the extra edges;</p><p>ans = ans — leng ; // do not have to delete the matching edges</p><p>ans = ans+ (n-1) ; // add n-1 self loops</p><p>ans = ans-leng ; // 'leng' number of vertices do not need self loop; </p><p>Hope it helps somebody.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-335415 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-335415 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-335415\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159679\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/raylee\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/135528/avatar/52549c9492fe7c04.jpg'/> </a>\n <div><a href=\"/profile/raylee\" title=\"Specialist raylee\" class=\"rated-user user-cyan\">raylee</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/02/2014 11:07\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159679\" href=\"?#comment-159679\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"159679\" revisionCount=\"13\" revision=\"13\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">13</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"159679\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"135528\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159679\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In the problem D, said "The complexity is: <span class=\"tex-span\"><i>O</i>(<i>n</i><sup class=\"upper-index\">2</sup> <i>m</i>)</span> time." But n and m (2 ≤ n ≤ 500, 1 ≤ m ≤ 1000). Can you explain why this complexity wont TLE? thank you.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159679 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159679 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159679\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159685\" commentParentId=\"159679\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/gridnevvvit\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/31163/avatar/db500a30a0b0a6f1.jpg'/> </a>\n <div><a href=\"/profile/gridnevvvit\" title=\"Candidate Master gridnevvvit\" class=\"rated-user user-violet\">gridnevvvit</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/02/2014 11:55\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159685\" href=\"?#comment-159685\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159679\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159685\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"31163\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159685\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Yes. First, let's calculate number of operations: it is about <span class=\"tex-span\">2 * 10<sup class=\"upper-index\">8</sup></span>. It is not so much. If you have good implementation of Kuhn, it would pass. Also, I know, that number of operation is much lower than <span class=\"tex-span\">2 * 10<sup class=\"upper-index\">8</sup></span>.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159685 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159685 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159685\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159689\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/1nikhil9\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/60595/avatar/64f85d0070290be7.jpg'/> </a>\n <div><a href=\"/profile/1nikhil9\" title=\"Candidate Master 1nikhil9\" class=\"rated-user user-violet\">1nikhil9</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/02/2014 14:07\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159689\" href=\"?#comment-159689\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159689\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"60595\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159689\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Test case 4 for Problem D says N = 153, M = 392. But there are only 391 edges in the input file.</p><p><a href=\"//codeforces.com/contest/387/submission/5868021\">http://codeforces.com/contest/387/submission/5868021</a></p><p>Am I misunderstanding something? Thanks.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159689 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159689 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159689\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159694\" commentParentId=\"159689\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/gridnevvvit\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/31163/avatar/db500a30a0b0a6f1.jpg'/> </a>\n <div><a href=\"/profile/gridnevvvit\" title=\"Candidate Master gridnevvvit\" class=\"rated-user user-violet\">gridnevvvit</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/02/2014 15:06\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159694\" href=\"?#comment-159694\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159689\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159694\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"31163\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159694\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Testcase is valid.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159694 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159694 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159694\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"160860\" commentParentId=\"159694\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/khrak\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/128936/avatar/6d9b38f723c23a83.jpg'/> </a>\n <div><a href=\"/profile/khrak\" title=\"Expert khrak\" class=\"rated-user user-blue\">khrak</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/07/2014 20:07\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-160860\" href=\"?#comment-160860\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159694\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"160860\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"128936\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-160860\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>What does n variable mean in C problem tutorial? </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-160860 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-160860 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-160860\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"160876\" commentParentId=\"160860\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/gridnevvvit\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/31163/avatar/db500a30a0b0a6f1.jpg'/> </a>\n <div><a href=\"/profile/gridnevvvit\" title=\"Candidate Master gridnevvvit\" class=\"rated-user user-violet\">gridnevvvit</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/08/2014 00:57\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-160876\" href=\"?#comment-160876\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-160860\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"160876\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"31163\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-160876\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>n is the length of the number from the input.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-160876 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-160876 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-160876\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"160894\" commentParentId=\"160876\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/khrak\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/128936/avatar/6d9b38f723c23a83.jpg'/> </a>\n <div><a href=\"/profile/khrak\" title=\"Expert khrak\" class=\"rated-user user-blue\">khrak</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/08/2014 11:15\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-160894\" href=\"?#comment-160894\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-160876\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"160894\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"128936\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-160894\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>So, for 800101 we have a1 = 800, a2 = 10, a3 = 1, and n = 6. what value has i for this example, 1 or -1? </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-160894 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-160894 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-160894\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"160913\" commentParentId=\"160894\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/gridnevvvit\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/31163/avatar/db500a30a0b0a6f1.jpg'/> </a>\n <div><a href=\"/profile/gridnevvvit\" title=\"Candidate Master gridnevvvit\" class=\"rated-user user-violet\">gridnevvvit</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/08/2014 14:34\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-160913\" href=\"?#comment-160913\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-160894\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"160913\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"31163\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-160913\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>i equals to -1. I understood, that there is an small mistake: answer is <span class=\"tex-span\"><i>k</i> - <i>i</i> + 1</span></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-160913 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-160913 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-160913\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"160924\" commentParentId=\"160913\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/khrak\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/128936/avatar/6d9b38f723c23a83.jpg'/> </a>\n <div><a href=\"/profile/khrak\" title=\"Expert khrak\" class=\"rated-user user-blue\">khrak</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/08/2014 16:02\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-160924\" href=\"?#comment-160924\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-160913\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"160924\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"128936\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-160924\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Sorry for so many questions, but I can't still understand how we count answer answer for 800101. here k equals 3, i equals -1 (as you said), then answer should be k — i + 1 = 3 — (-1) + 1 = 5 when answer here is 3.. What I didn't understand correctly? </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-160924 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-160924 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-160924\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"160928\" commentParentId=\"160924\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/gridnevvvit\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/31163/avatar/db500a30a0b0a6f1.jpg'/> </a>\n <div><a href=\"/profile/gridnevvvit\" title=\"Candidate Master gridnevvvit\" class=\"rated-user user-violet\">gridnevvvit</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/08/2014 17:23\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-160928\" href=\"?#comment-160928\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-160924\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"160928\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"31163\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-160928\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Oh, it's my mistake. If there is no such index, index i should be equals to 1, yes.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-160928 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-160928 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-160928\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"160929\" commentParentId=\"160928\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/khrak\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/128936/avatar/6d9b38f723c23a83.jpg'/> </a>\n <div><a href=\"/profile/khrak\" title=\"Expert khrak\" class=\"rated-user user-blue\">khrak</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/08/2014 17:27\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-160929\" href=\"?#comment-160929\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-160928\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"160929\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"128936\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-160929\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Okey. Then I understand and I'll think about proof. Thank you! :) </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-160929 en true\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-160929 en true\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-160929\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"161379\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/rohitjv\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/107177/avatar/3326d08f28613bd4.jpg'/> </a>\n <div><a href=\"/profile/rohitjv\" title=\"Expert rohitjv\" class=\"rated-user user-blue\">rohitjv</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/12/2014 21:33\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-161379\" href=\"?#comment-161379\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"161379\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"107177\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-161379\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In problem C, the definition of the array <em>need[i]</em> in the description does not match with the code provided. The actual definition of <em>need[i]</em> should be : need[i] — equals to <strong>0</strong> if we should remove number i from permutation p, and <strong>1</strong> if we shouldn't remove i from permutation p. Please correct me if I am wrong.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-161379 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-161379 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-161379\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"161380\" commentParentId=\"161379\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/gridnevvvit\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/31163/avatar/db500a30a0b0a6f1.jpg'/> </a>\n <div><a href=\"/profile/gridnevvvit\" title=\"Candidate Master gridnevvvit\" class=\"rated-user user-violet\">gridnevvvit</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/12/2014 21:56\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-161380\" href=\"?#comment-161380\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-161379\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"161380\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"31163\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-161380\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Yes, description does not match with the code provided. There are only ideas in editorial, so there are can be differences. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-161380 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-161380 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-161380\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"161811\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Nakochi\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/101746/avatar/ccfafe3f7587f95d.jpg'/> </a>\n <div><a href=\"/profile/Nakochi\" title=\"Expert Nakochi\" class=\"rated-user user-blue\">Nakochi</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/17/2014 18:23\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-161811\" href=\"?#comment-161811\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"161811\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"101746\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-161811\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Problem C is really a challenge for me!!! Orz!!!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-161811 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-161811 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-161811\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"161820\" commentParentId=\"161811\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Nodir.Daminov\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/71439/avatar/d6d2016f6dfe5ecd.jpg'/> </a>\n <div><a href=\"/profile/Nodir.Daminov\" title=\"Candidate Master Nodir.Daminov\" class=\"rated-user user-violet\">Nodir.Daminov</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/17/2014 19:19\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-161820\" href=\"?#comment-161820\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-161811\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"161820\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"71439\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-161820\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Who cares ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-161820 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-161820 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-161820\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"161902\" commentParentId=\"161820\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Nakochi\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/101746/avatar/ccfafe3f7587f95d.jpg'/> </a>\n <div><a href=\"/profile/Nakochi\" title=\"Expert Nakochi\" class=\"rated-user user-blue\">Nakochi</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/18/2014 18:14\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-161902\" href=\"?#comment-161902\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-161820\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"161902\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"101746\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-161902\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Sorry, I misunderstood the problem. Now it's much easier. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-161902 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-161902 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-161902\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"161903\" commentParentId=\"161902\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Nodir.Daminov\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/71439/avatar/d6d2016f6dfe5ecd.jpg'/> </a>\n <div><a href=\"/profile/Nodir.Daminov\" title=\"Candidate Master Nodir.Daminov\" class=\"rated-user user-violet\">Nodir.Daminov</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/18/2014 18:25\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-161903\" href=\"?#comment-161903\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-161902\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"161903\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"71439\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-161903\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Who cares ???</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-161903 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-161903 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-161903\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"161904\" commentParentId=\"161903\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Nakochi\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/101746/avatar/ccfafe3f7587f95d.jpg'/> </a>\n <div><a href=\"/profile/Nakochi\" title=\"Expert Nakochi\" class=\"rated-user user-blue\">Nakochi</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/18/2014 18:54\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-161904\" href=\"?#comment-161904\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-161903\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"161904\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"101746\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-161904\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Seems you care. :D</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-161904 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-161904 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-161904\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n <br/>\r\n\r\n<div id=\"editBox-10654\" style=\"width:50em;display:none;\">\r\n <div class=\"previewBody\" style=\"border: 1px solid #d4d4d4; margin-bottom: 0.5em; padding: 0.25em; display:none;\"> </div>\r\n <div style=\"width: 1px\"> </div>\r\n <div class=\"commentLocale\" style=\"position: relative; top: 0.5em;left:4px;display: none;\">\r\n <input type=\"radio\" name=\"locale\" value=\"en\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In English</span>\r\n <input style=\"margin-left:1em\" type=\"radio\" name=\"locale\" value=\"ru\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In Russian</span>\r\n </div>\r\n <textarea data-drafts-id=\"CommentReplyFrame\" class=\"wysiwyg\" name=\"editContent\" rows=\"20\" style=\"width:99%;\"></textarea>\r\n <div class=\"error error__content\"></div>\r\n <div style=\"text-align:center;\">\r\n <input type=\"button\" name=\"preview\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Preview\"/>\r\n <input type=\"button\" name=\"save\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Save\"/>\r\n </div>\r\n</div>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n\r\nvar firstPreview10654 = true;\r\nvar lastPreviewContent10654 = '';\r\n\r\nif (!window.moveCommentRevision) {\r\n moveCommentRevision = function(e, dir) {\r\n var p = e.parent();\r\n var revisionCount = parseInt(p.attr(\"revisionCount\"));\r\n var revision = parseInt(p.attr(\"revision\"));\r\n var next = revision + dir;\r\n var commentId = p.attr(\"commentId\");\r\n if (next >= 1 && next <= revisionCount) {\r\n $.post(\r\n \"/data/comment-data\",\r\n {action: \"revision\", commentId: commentId, revision: next},\r\n function(json) {\r\n if (json.success == \"true\") {\r\n var parentDiv = e;\r\n\r\n while (parentDiv !== null && (parentDiv[0].nodeName.toLowerCase() !== \"td\" || !parentDiv.hasClass(\"right\"))) {\r\n parentDiv = parentDiv.parent();\r\n }\r\n\r\n if (parentDiv === null) {\r\n return;\r\n }\r\n\r\n parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\").html(json.content);\r\n Codeforces.setupSpoilers(parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\"));\r\n p.attr(\"revision\", next);\r\n p.find(\"span.revision\").text(next);\r\n if (next == 1) {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"visible\");\r\n }\r\n if (next == revisionCount) {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"visible\");\r\n }\r\n\r\n window.updateTypography();\r\n MathJax.Hub.Typeset();\r\n } else {\r\n alert(e.error);\r\n }\r\n },\r\n \"json\"\r\n );\r\n }\r\n };\r\n}\r\n\r\n$(\"div[commentableId=10654] a.leftRevision\").click(function () {\r\n window.moveCommentRevision($(this), -1);\r\n return false;\r\n});\r\n\r\n$(\"div[commentableId=10654] a.rightRevision\").click(function () {\r\n window.moveCommentRevision($(this), +1);\r\n return false;\r\n});\r\n\r\n\r\n\r\n });\n </script>\n\r\n\r\n <script src=\"//codeforces.org/s/81027/js/swfobject-2.2.min.js\" type=\"text/javascript\"></script>\n <script src=\"//codeforces.org/s/81027/js/ftaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n if (window.evercookie) {\n var ec = new evercookie({\n history: false,\n silverlight: false,\n baseurl: '',\n asseturi: '/assets',\n phpuri: '/2fdcd78',\n pngPath: '/eps',\n etagPath: '/ees',\n cachePath: '/ecs'\n });\n\n var randomNumber = function () {\n return Math.random().toString(36).substr(2);\n };\n\n var randomToken = function () {\n return (randomNumber() + randomNumber()).substring(0, 18);\n };\n\n window._ftaa = \"\";\n\n ec.get(\"70a7c28f3de\", function (value) {\n window._ftaa = value;\n if (!window._ftaa) {\n window._ftaa = randomToken();\n ec.set(\"70a7c28f3de\", window._ftaa);\n }\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n } else {\n window._ftaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\n <script src=\"//codeforces.org/s/81027/js/bfaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n var fpCallback = function() {\n Fingerprint2.get({}, function(components) {\n window._bfaa = Fingerprint2.x64hash128(components.map(function (pair) { return pair.value }).join(), 31);\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n };\n if (typeof Fingerprint2 !== 'undefined') {\n if (window.requestIdleCallback) {\n requestIdleCallback(fpCallback)\n } else {\n setTimeout(fpCallback, 500)\n }\n } else {\n window._bfaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"a.new-root-comment\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n\r\n $(\".comment-table .reply a\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".vote-for-comment\").mouseover(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").mouseout(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").click(function () {\r\n var vote = $(this);\r\n var commentId = $(this).parent().attr(\"commentid\");\r\n var commentRating = $(this).parent().attr(\"data-commentRating\");\r\n var direction = $(this).attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n $.post(\"/data/comment/vote\", {commentId: commentId, _tta: Codeforces.tta(), vote: direction, commentRating: commentRating}, function(data) {\r\n if (direction != 0 && !ownComment && data[\"success\"] == \"true\") {\r\n vote.parent().find(\".vote-for-comment\").attr(\"voteDirection\", 0);\r\n if (direction == 1)\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n else {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.closest(\".CommentVoteFrame\").find(\".ComplaintFrame\").css(\"display\", \"inline-block\");\r\n }\r\n vote.find(\"img\").attr(\"popacity\", \"1.0\");\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n vote.parent().find(\".commentRating\").html(data[\"commentRating\"]);\r\n }\r\n Codeforces.showMessage(data[\"message\"]);\r\n }, \"json\");\r\n return false;\r\n });\r\n\r\n $(\".negative-comment-vote\").closest(\".comment-table\").addClass(\"comment-bad\");\r\n\r\n $(\".troll-comment-vote\").closest(\".comment\").css(\"display\", \"none\");\r\n\r\n $(\".too-negative-comment-vote\").closest(\".comment-table\").each(function () {\r\n var e = $(this);\r\n e.addClass(\"comment-too-bad\");\r\n var commentId = e.attr(\"commentId\");\r\n $(\"<div class='bad-comment-replacement ttypography'>The comment is hidden because of too negative feedback, click <a href=# class=show-bad-comment-link>here</a> to view it</div>\").appendTo(\r\n e.find(\".right\")\r\n );\r\n e.find(\".comment-content\").hide();\r\n e.find(\".show-bad-comment-link\").click(function () {\r\n e.find(\".comment-content\").show();\r\n e.find(\".bad-comment-replacement\").hide();\r\n return false;\r\n });\r\n });\r\n });\n </script>\n </div>\r\n\r\n <style type=\"text/css\">\r\n .new-comments-box {\r\n padding: 0.5em;\r\n width: 22px;\r\n font-size: 1.3rem;\r\n font-weight: bold !important;\r\n\r\n position: fixed;\r\n top: 40%;\r\n right: 0;\r\n opacity: 0.2;\r\n color: white;\r\n text-align: center;\r\n\r\n border: 1px solid #222;\r\n background-color: #888 !important;\r\n border-radius: 3px;\r\n -moz-border-radius: 3px;\r\n -webkit-border-radius: 3px;\r\n }\r\n\r\n .new-comments-box:hover {\r\n opacity: 1;\r\n }\r\n\r\n .new-comments-box .dir:hover {\r\n background: #3B5998 !important;\r\n cursor: pointer;\r\n }\r\n </style>\r\n\r\n <div class=\"new-comments-box\" data-position=\"outside\" data-index=\"-1\" style=\"display: none;\">\r\n <div class=\"up dir\" title=\"Ctrl+Up\">↑<hr/>\r\n </div>\r\n <div class=\"info\" title=\"New comments\"></div>\r\n <div class=\"down dir\" title=\"Ctrl+Down\">\r\n <hr/>↓\r\n </div>\r\n </div>\r\n\r\n <script>\r\n $(\".show-archived-checkbox\").change(function () {\r\n const checked = $(this).is(\":checked\");\r\n $.post(\"/data/comment-data\", {action: \"setShowArchived\", checked}, function (json) {\r\n if (json[\"success\"] !== \"true\") {\r\n alert(json[\"error\"]);\r\n } else {\r\n if (checked) {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are now displayed\")\r\n } else {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are no longer displayed\")\r\n }\r\n }\r\n });\r\n return false;\r\n });\r\n\r\n function gotoComment(direction) {\r\n var box = $(\".new-comments-box\");\r\n var index = parseInt(box.attr(\"data-index\"));\r\n if (index == -1)\r\n index = 0;\r\n else\r\n index = Math.max(0, Math.min(parseInt(box.find(\".info\").text()) - 1, index + direction));\r\n box.attr(\"data-index\", index);\r\n var comment = $($(\".comment .highlight-blue[commentId]\").get(index));\r\n $('html, body').animate({\r\n 'scrollTop': Math.max(0, comment.offset().top - ($(window).height() - comment.height()) / 2)\r\n });\r\n return false;\r\n }\r\n\r\n $(\".new-comments-box .down\").click(function () {\r\n return gotoComment(1);\r\n });\r\n\r\n $(\".new-comments-box .up\").click(function () {\r\n return gotoComment(-1);\r\n });\r\n\r\n $(document).keydown(function (e) {\r\n var code = (e.keyCode ? e.keyCode : e.which);\r\n if (e.ctrlKey) {\r\n if (code == 38 || code == 40) {\r\n gotoComment(code - 39);\r\n }\r\n }\r\n });\r\n\r\n var newCommentCount = $(\".comment .highlight-blue[commentId]\").length;\r\n if (newCommentCount > 0) {\r\n $(\".new-comments-box .info\").text(newCommentCount);\r\n $(\".new-comments-box\").show();\r\n }\r\n\r\n $('table.comment-table').mouseenter(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").addClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n\r\n $('table.comment-table').mouseleave(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").removeClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n </script>\r\n\r\n\r\n\r\n <script>\r\n function adjustTopicComplainFrames() {\r\n let topicIds = [];\r\n\r\n $(\".has-topic-id\").each(function () {\r\n const $this = $(this);\r\n const topicId = $this.attr(\"topicId\");\r\n if (topicId) {\r\n topicIds.push(topicId);\r\n }\r\n });\r\n\r\n $.post(\"/data/topics\", {\r\n action: \"findComplainableTopicIds\",\r\n topicIds: topicIds.join(\",\")\r\n }, function (json) {\r\n if (json[\"success\"] === \"true\") {\r\n for (const topicId of json[\"complainableTopicIds\"].split(\",\")) {\r\n $(\".has-topic-id[topicId=\" + topicId + \"]\").each(function () {\r\n $(this).find(\".meta .ComplaintFrame\").css(\"display\", \"inline-block\");\r\n });\r\n }\r\n }\r\n }, \"json\");\r\n }\r\n\r\n $(function () {\r\n adjustTopicComplainFrames();\r\n })\r\n </script>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-10638\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 10638, _tta: Codeforces.tta(), topicRevisionId: 37197, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-10638\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 10638, _tta: Codeforces.tta(), topicRevisionId: 37197, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n </div>\r\n </div>\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 22:13:05</span> (h1).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/81027/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/81027/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/81027/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/81027/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-81027.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'812875999be52de2',t:'MTY5NjcwNTk4NS43NTIwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"}}},{"rowIdx":1958,"cells":{"problem_id":{"kind":"string","value":"388A"},"contest":{"kind":"string","value":"388"},"problem":{"kind":"string","value":"A"},"lang":{"kind":"string","value":"en"},"problem_title":{"kind":"string","value":"A. Fox and Box Accumulation"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">A. Fox and Box Accumulation</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Fox Ciel has <span class=\"tex-span\"><i>n</i></span> boxes in her room. They have the same size and weight, but they might have different strength. The <span class=\"tex-span\"><i>i</i></span>-th box can hold at most <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span> boxes on its top (we'll call <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span> the strength of the box). </p><p>Since all the boxes have the same size, Ciel cannot put more than one box directly on the top of some box. For example, imagine Ciel has three boxes: the first has strength 2, the second has strength 1 and the third has strength 1. She cannot put the second and the third box simultaneously directly on the top of the first one. But she can put the second box directly on the top of the first one, and then the third box directly on the top of the second one. We will call such a construction of boxes a <span class=\"tex-font-style-it\">pile</span>.</p><center><img class=\"tex-graphics\" src=\"https://espresso.codeforces.com/97f4897ba81d44a26f9d9efcf7fc3cb427ba885b.png\" style=\"max-width: 100.0%;max-height: 100.0%;\"/></center><p>Fox Ciel wants to construct piles from all the boxes. Each pile will contain some boxes from top to bottom, and there cannot be more than <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span> boxes on the top of <span class=\"tex-span\"><i>i</i></span>-th box. What is the minimal number of piles she needs to construct?</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains an integer <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">1 ≤ <i>n</i> ≤ 100</span>). The next line contains <span class=\"tex-span\"><i>n</i></span> integers <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">1</sub>, <i>x</i><sub class=\"lower-index\">2</sub>, ..., <i>x</i><sub class=\"lower-index\"><i>n</i></sub></span> (<span class=\"tex-span\">0 ≤ <i>x</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 100</span>).</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Output a single integer — the minimal possible number of piles.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>3<br/>0 0 10<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>2<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>5<br/>0 1 2 3 4<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>4<br/>0 0 0 0<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>4<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>9<br/>0 1 0 2 0 1 1 2 10<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>3<br/></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>In example 1, one optimal way is to build 2 piles: the first pile contains boxes 1 and 3 (from top to bottom), the second pile contains only box 2.</p><center><img class=\"tex-graphics\" src=\"https://espresso.codeforces.com/8cc9a4fa88a6ae1c5f8d28bad6f46baf9fb52988.png\" style=\"max-width: 100.0%;max-height: 100.0%;\"/></center><p>In example 2, we can build only 1 pile that contains boxes 1, 2, 3, 4, 5 (from top to bottom).</p><center><img class=\"tex-graphics\" src=\"https://espresso.codeforces.com/51e8d6552ca61c237a2e7df55cef2cd62741f5c4.png\" style=\"max-width: 100.0%;max-height: 100.0%;\"/></center></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"ab6ca88bad5ff4527612576bf6694a2d\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - A - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"fe71135886e33994ae4d9b5e4703fc32ee0c7819\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - A - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/73366/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/73366/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/73366/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/73366/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/73366/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/73366/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/73366/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/73366/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/73366/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/73366/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/73366/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/73366/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/73366/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/73366/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/sidebar-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/a037fe51637846d9c7c725713cd840ea/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='ab6ca88bad5ff4527612576bf6694a2d'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/73366/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/73366/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fcontest%2F388%2Fproblem%2FA%3Flocale%3Den\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"current\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='ab6ca88bad5ff4527612576bf6694a2d'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:100%;\"><a style=\"color: black\" href=\"/contest/388\">Codeforces Round 228 (Div. 1)</a></th>\n </tr>\n <tr>\n <td class=\"left bottom\" colspan=\"1\"><span class=\"contest-state-phase\">Finished</span></td>\n </tr>\n </tbody>\n </table>\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Practice?\n <div class=\"top-links\">\n </div>\n </div>\n<div>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Want to solve the contest problems after the official contest ends? Just register for practice and you will be able to submit solutions.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"\" method=\"post\"><input type='hidden' name='csrf_token' value='ab6ca88bad5ff4527612576bf6694a2d'/>\r\n <input type=\"hidden\" name=\"action\" value=\"registerForPractice\"/>\r\n <input type=\"submit\" name=\"submit\" value=\"Register for practice\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div> \r\n</div>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox ContestVirtualFrame borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Virtual participation <i class=\"sidebar-caption-icon las la-angle-down\"></i>\r\n\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\" \"\r\n\r\n data-page-url=\"/data/sidebarFrames\"\r\n\r\n>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests.\n\nIf you've seen these problems, a virtual contest is not for you - solve these problems in the archive.\n\nIf you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.\n\nNever use someone else's code, read the tutorials or communicate with other person during a virtual contest.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"/contest/388/virtual\" method=\"get\">\r\n <input type=\"submit\" name=\"submit\" value=\"Start virtual contest\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div>\r\n</div>\r\n <script>\r\n $(function () {\r\n $(\".ContestVirtualFrame .sidebar-caption-icon\").click(function() {\r\n $(this).toggleClass(\"la-angle-down la-angle-right\");\r\n const $target = $(this).parent().next();\r\n $target.toggle();\r\n const dataPageUrl = $target.attr(\"data-page-url\");\r\n const collapsed = $(this).hasClass(\"la-angle-right\");\r\n const params = {\r\n action: \"setCollapsed\",\r\n sidebarFrameSimpleClassName: \"ContestVirtualFrame\",\r\n collapsed\r\n };\r\n $.each($target[0].attributes, function(i, a) {\r\n const name = a.name;\r\n if (name.startsWith(\"data-extra-key-\")) {\r\n const key = a.value;\r\n const keyIndex = parseInt(name.substring(\"data-extra-key-\".length));\r\n const value = $target.attr(\"data-extra-value-\" + keyIndex);\r\n params[key] = value;\r\n }\r\n });\r\n $.post(dataPageUrl, params, function (result) {\r\n if (result[\"success\"] !== \"true\") {\r\n Codeforces.showMessage(\"Failed to save collapsed state.\");\r\n }\r\n }, \"json\");\r\n return false;\r\n });\r\n })\r\n </script>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Problem tags\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Greedy algorithms\">\r\n greedy\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Sortings, orderings\">\r\n sortings\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Difficulty\">\r\n *1400\r\n</span>\r\n </div>\n <div style=\"clear:both;text-align:right;font-size:1.1rem;\">\r\n <span title=\"Please login into the Codeforces\" class=\"notice\">No tag edit access</span>\r\n </div>\r\n</div>\r\n </div>\n\r\n<form id=\"addTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='ab6ca88bad5ff4527612576bf6694a2d'/>\r\n <input name=\"action\" type=\"hidden\" value=\"addTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"6405\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<form id=\"removeTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='ab6ca88bad5ff4527612576bf6694a2d'/>\r\n <input name=\"action\" type=\"hidden\" value=\"removeTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"6405\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<script type=\"text/javascript\">\r\n $(\".tag-box img\").click(function () {\r\n var tagName = $(this).attr(\"value\");\r\n Codeforces.confirm(\"Are you sure you want to remove this tag?\", function () {\r\n $(\"#removeTagForm input[name=tagName]\").val(tagName);\r\n $(\"#removeTagForm\").submit();\r\n }, function () {\r\n }, \"Yes\", \"No\");\r\n });\r\n\r\n $(\"#addTagLink\").click(function () {\r\n $(this).hide();\r\n $(\"#addTagLabel\").show();\r\n return false;\r\n });\r\n\r\n $(\"#addTagSelect\").change(function () {\r\n var tagName = $(this).val();\r\n if (tagName === \"\") {\r\n $(\"#addTagLabel\").hide();\r\n $(\"#addTagLink\").show();\r\n } else {\r\n $(\"#addTagForm input[name=tagName]\").val(tagName);\r\n $(\"#addTagForm\").submit();\r\n }\r\n });\r\n</script>\r\n\r\n<style type=\"text/css\">\r\n#new-resource-form tr td {\r\npadding-top: 0.5em;\r\n}\r\n#new-resource-form input:not([type=\"submit\"]) {\r\nfont-size: 0.8em;\r\n}\r\n#new-resource-form select {\r\nfont-size: 0.8em;\r\n}\r\n.new-resource-error {\r\nfont-size: 0.8em;\r\n}\r\n.resource-locale {\r\ncolor: #666;\r\nfont-family: Consolas, \"Andale Mono WT\", \"Andale Mono\", \"Lucida Console\", \"Lucida Sans Typewriter\", \"DejaVu Sans Mono\", \"Bitstream Vera Sans Mono\", \"Liberation Mono\", \"Nimbus Mono L\", Monaco, \"Courier New\", Courier, monospace;\r\n}\r\n</style>\r\n<div class=\"roundbox sidebox sidebar-menu borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Contest materials\n<div class=\"top-links\">\n</div>\n</div>\n<ul>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/10605\" title=\"Codeforces Round #228\" target=\"_blank\">Codeforces Round #228</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"2187:2188\" resourceName=\"Announcement\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/10629\" title=\"Codeforces Round #228 — Editorial\" target=\"_blank\">Tutorial <span class=\"resource-locale\">(en)</span></a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"2192\" resourceName=\"Codeforces Round #228 — Editorial\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n</ul>\r\n</div></div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li class=\"current selectedLava\"><a\r\n href=\"/contest/388\">Problems</a></li>\r\n <li><a\r\n href=\"/contest/388/submit\">Submit Code</a></li>\r\n <li><a\r\n href=\"/contest/388/my\">My Submissions</a></li>\r\n <li><a\r\n href=\"/contest/388/status\">Status</a></li>\r\n <li><a\r\n href=\"/contest/388/hacks\">Hacks</a></li>\r\n <li><a\r\n href=\"/contest/388/room/1\">Room</a></li>\r\n <li><a\r\n href=\"/contest/388/standings\">Standings</a></li>\r\n <li><a\r\n href=\"/contest/388/customtest\">Custom Invocation</a></li>\r\n</ul>\r\n</div>\n\r\n <style>\r\n #facebox .content:has(.diff-popup) {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n }\r\n\r\n .testCaseMarker {\r\n position: absolute;\r\n font-weight: bold;\r\n font-size: 1rem;\r\n }\r\n\r\n .diff-popup {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n display: none;\r\n overflow: auto;\r\n }\r\n\r\n .input-output-copier {\r\n font-size: 1.2rem;\r\n float: right;\r\n color: #888 !important;\r\n cursor: pointer;\r\n border: 1px solid rgb(185, 185, 185);\r\n padding: 3px;\r\n margin: 1px;\r\n line-height: 1.1rem;\r\n text-transform: none;\r\n }\r\n\r\n .input-output-copier:hover {\r\n background-color: #def;\r\n }\r\n\r\n .test-explanation textarea {\r\n width: 100%;\r\n height: 1.5em;\r\n }\r\n\r\n .pending-submission-message {\r\n color: darkorange !important;\r\n }\r\n </style>\r\n <script>\r\n const OPENING_SPACE = String.fromCharCode(1001);\r\n const CLOSING_SPACE = String.fromCharCode(1002);\r\n\r\n const nodeToText = function (node, pre) {\r\n let result = [];\r\n\r\n if (node.tagName === \"SCRIPT\" || node.tagName === \"math\"\r\n || (node.classList && node.classList.contains(\"input-output-copier\")))\r\n return [];\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(OPENING_SPACE);\r\n }\r\n\r\n if (node.nodeType === Node.TEXT_NODE) {\r\n let s = node.textContent;\r\n if (!pre) {\r\n s = s.replace(/\\s+/g, \" \");\r\n }\r\n if (s.length > 0) {\r\n result.push(s);\r\n }\r\n }\r\n\r\n if (pre && node.tagName === \"BR\") {\r\n result.push(\"\\n\");\r\n }\r\n\r\n node.childNodes.forEach(function (child) {\r\n result.push(nodeToText(child, node.tagName === \"PRE\").join(\"\"));\r\n });\r\n\r\n if (node.tagName === \"DIV\"\r\n || node.tagName === \"P\"\r\n || node.tagName === \"PRE\"\r\n || node.tagName === \"UL\"\r\n || node.tagName === \"LI\"\r\n ) {\r\n result.push(\"\\n\");\r\n }\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(CLOSING_SPACE);\r\n }\r\n\r\n return result;\r\n }\r\n\r\n const isSpecial = function (c) {\r\n return c === ',' || c === '.' || c === ';' || c === ')' || c === ' ';\r\n }\r\n\r\n const convertStatementToText = function(statmentNode) {\r\n const text = nodeToText(statmentNode, false).join(\"\").replace(/ +/g, \" \").replace(/\\n\\n+/g, \"\\n\\n\");\r\n let result = [];\r\n for (let i = 0; i < text.length; i++) {\r\n const c = text.charAt(i);\r\n if (c === OPENING_SPACE) {\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"A\" data-uuid=\"ps_2996ba9c60a96a88917a21b990f8e906b8167a94\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">A. Fox and Box Accumulation</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Fox Ciel has <span class=\"tex-span\"><i>n</i></span> boxes in her room. They have the same size and weight, but they might have different strength. The <span class=\"tex-span\"><i>i</i></span>-th box can hold at most <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span> boxes on its top (we'll call <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span> the strength of the box). </p><p>Since all the boxes have the same size, Ciel cannot put more than one box directly on the top of some box. For example, imagine Ciel has three boxes: the first has strength 2, the second has strength 1 and the third has strength 1. She cannot put the second and the third box simultaneously directly on the top of the first one. But she can put the second box directly on the top of the first one, and then the third box directly on the top of the second one. We will call such a construction of boxes a <span class=\"tex-font-style-it\">pile</span>.</p><center><img class=\"tex-graphics\" src=\"https://espresso.codeforces.com/97f4897ba81d44a26f9d9efcf7fc3cb427ba885b.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></center><p>Fox Ciel wants to construct piles from all the boxes. Each pile will contain some boxes from top to bottom, and there cannot be more than <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span> boxes on the top of <span class=\"tex-span\"><i>i</i></span>-th box. What is the minimal number of piles she needs to construct?</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains an integer <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">1 ≤ <i>n</i> ≤ 100</span>). The next line contains <span class=\"tex-span\"><i>n</i></span> integers <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">1</sub>, <i>x</i><sub class=\"lower-index\">2</sub>, ..., <i>x</i><sub class=\"lower-index\"><i>n</i></sub></span> (<span class=\"tex-span\">0 ≤ <i>x</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 100</span>).</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Output a single integer — the minimal possible number of piles.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>3<br />0 0 10<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>2<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>5<br />0 1 2 3 4<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>4<br />0 0 0 0<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>4<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>9<br />0 1 0 2 0 1 1 2 10<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>3<br /></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>In example 1, one optimal way is to build 2 piles: the first pile contains boxes 1 and 3 (from top to bottom), the second pile contains only box 2.</p><center><img class=\"tex-graphics\" src=\"https://espresso.codeforces.com/8cc9a4fa88a6ae1c5f8d28bad6f46baf9fb52988.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></center><p>In example 2, we can build only 1 pile that contains boxes 1, 2, 3, 4, 5 (from top to bottom).</p><center><img class=\"tex-graphics\" src=\"https://espresso.codeforces.com/51e8d6552ca61c237a2e7df55cef2cd62741f5c4.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></center></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=A]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== statementText) {\r\n $problem.find(\".diff-notifier\").show();\r\n\r\n $problem.find(\".diff-notifier-close\").click(function() {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n $problem.find(\".diff-notifier\").hide();\r\n });\r\n\r\n $problem.find(\"a.view-changes\").click(function() {\r\n $.post(\"/data/diff\", {action: \"getDiff\", a: previousStatementText, b: statementText}, function (result) {\r\n if (result[\"success\"] === \"true\") {\r\n Codeforces.facebox(\".diff-popup\", \"//codeforces.org/s/73366\");\r\n $(\"#facebox .diff-popup\").html(result[\"diff\"]);\r\n }\r\n }, \"json\");\r\n });\r\n }\r\n } else {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n }\r\n });\r\n });\r\n </script>\r\n\r\n\r\n<script type=\"text/javascript\">\r\n $(document).ready(function () {\r\n window.changedTests = new Set();\r\n\r\n function endsWith(string, suffix) {\r\n return string.indexOf(suffix, string.length - suffix.length) !== -1;\r\n }\r\n\r\n const inputFileDiv = $(\"div.input-file\");\r\n const inputFile = inputFileDiv.text();\r\n const outputFileDiv = $(\"div.output-file\");\r\n const outputFile = outputFileDiv.text();\r\n\r\n\r\n if (!endsWith(inputFile, \"standard input\")\r\n && !endsWith(inputFile, \"standard input\")) {\r\n inputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n if (!endsWith(outputFile, \"standard output\")\r\n && !endsWith(outputFile, \"standard output\")) {\r\n outputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n const titleDiv = $(\"div.header div.title\");\r\n\r\n\r\n\r\n String.prototype.replaceAll = function (search, replace) {\r\n return this.split(search).join(replace);\r\n };\r\n\r\n $(\".sample-test .title\").each(function () {\r\n const preId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n const cpyId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n\r\n $(this).parent().find(\"pre\").attr(\"id\", preId);\r\n const $copy = $(\"<div title='Copy' data-clipboard-target='#\" + preId + \"' id='\" + cpyId + \"' class='input-output-copier'>Copy</div>\");\r\n $(this).append($copy);\r\n\r\n const clipboard = new Clipboard('#' + cpyId, {\r\n text: function (trigger) {\r\n const pre = document.querySelector('#' + preId);\r\n const lines = pre.querySelectorAll(\".test-example-line\");\r\n return Codeforces.filterClipboardText(pre.innerText, lines.length);\r\n }\r\n });\r\n\r\n const isInput = $(this).parent().hasClass(\"input\");\r\n\r\n clipboard.on('success', function (e) {\r\n if (isInput) {\r\n Codeforces.showMessage(\"The example input has been copied into the clipboard\");\r\n } else {\r\n Codeforces.showMessage(\"The example output has been copied into the clipboard\");\r\n }\r\n e.clearSelection();\r\n });\r\n });\r\n\r\n $(\".test-form-item input\").change(function () {\r\n addPendingSubmissionMessage($($(this).closest(\"form\")), \"You changed the answer, do not forget to submit it if you want to save the changes\");\r\n const index = $(this).closest(\".problemindexholder\").attr(\"problemindex\");\r\n let test = \"\";\r\n $(this).closest(\"form input\").each(function () {\r\n const test_ = $(this).attr(\"name\");\r\n if (test_ && test_.substring(0, 4) === \"test\") {\r\n test = test_;\r\n }\r\n });\r\n if (index.length > 0 && test.length > 0) {\r\n const indexTest = index + \"::\" + test;\r\n window.changedTests.add(indexTest);\r\n }\r\n });\r\n\r\n $(window).on('beforeunload', function () {\r\n if (window.changedTests.size > 0) {\r\n return 'Dialog text here';\r\n }\r\n });\r\n\r\n autosize($('.test-explanation textarea'));\r\n\r\n $(\".test-example-line\").hover(function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n let top = 1E20;\r\n let left = 1E20;\r\n let problem = $(this).closest(\".problemindexholder\");\r\n $(this).closest(\".input\").find(\".\" + clazz).css(\"background-color\", \"#FFFDE7\").each(function() {\r\n top = Math.min(top, $(this).offset().top);\r\n left = Math.min(left, $(this).offset().left);\r\n });\r\n let testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n if (testCaseMarker.length === 0) {\r\n const html = \"<div class=\\\"testCaseMarker testCaseMarker_\" + end + \" notice\\\"></div>\";\r\n problem.append($(html));\r\n testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n }\r\n if (testCaseMarker) {\r\n testCaseMarker.show()\r\n .offset({top, left: left - 20})\r\n .text(end);\r\n }\r\n }\r\n }\r\n });\r\n }, function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n $(\".\" + clazz).css(\"background-color\", \"\");\r\n $(this).closest(\".problemindexholder\").find(\".testCaseMarker_\" + end).hide();\r\n }\r\n }\r\n });\r\n });\r\n\r\n });\r\n</script>\r\n\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 05:38:29</span> (j3).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/73366/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/73366/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/73366/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/73366/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-73366.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'8122c4ab386216c3',t:'MTY5NjY0NjMwOS44MDkwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"},"long_tags":{"kind":"string","value":"[\"Greedy algorithms\", \"Sortings, orderings\"]"},"short_tags":{"kind":"string","value":"[\"greedy\", \"sortings\", \"*1400\"]"},"tutorial_link":{"kind":"string","value":"https://codeforces.com/blog/entry/10629"},"tutorial_page":{"kind":"string","value":"\r\n\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"74361418aed3add319d25ce966ceafdf\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"h1\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Codeforces Round #228 — Editorial - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n \n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Codeforces Round #228 — Editorial - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/81027/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/81027/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/81027/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/81027/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/81027/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/81027/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/81027/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/81027/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/81027/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/81027/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/81027/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/81027/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/81027/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/81027/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/573cedc6b04c15481941f418269f4057/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='74361418aed3add319d25ce966ceafdf'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/81027/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fblog%2Fentry%2F10629\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='74361418aed3add319d25ce966ceafdf'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Pay attention\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n <div style=\"text-align:center;border-bottom: 1px solid rgb(185, 185, 185);margin:0 -0.5em 0.5em -0.5em;padding: 0 1em 0.5em 1em;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 1, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:51:54</span><br/><a href=\"/contestRegistration/1876\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n <div style=\"text-align:center;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 2, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:51:54</span><br/><a href=\"/contestRegistration/1877\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='74361418aed3add319d25ce966ceafdf'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n </label>\r\n </div>\r\n <div style=\"padding: 0 1em 1em 1em;text-align:right;\">\r\n <input style=\"height:1.65em;padding:0 0.75em;\" type=\"submit\" value=\"Find\"/>\r\n </div>\r\n </form>\r\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".handleBox\").autocomplete(\"/data/handles\", {\r\n delay: 200,\r\n width: 200,\r\n selectFirst: false,\r\n matchContains: true,\r\n minChars: 3\r\n });\r\n $(\".handleForm\").attr(\"autocomplete\", \"off\").submit(function () {\r\n var link = \"/profile/userHandle\".replace(\r\n \"userHandle\", $(this).find(\".handleBox\").val()\r\n );\r\n window.location = link;\r\n return false;\r\n });\r\n });\n </script>\n\r\n\r\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Recent actions\n <div class=\"top-links\">\n </div>\n </div>\n <div class=\"recent-actions\">\r\n <ul>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/121073\">Meta Hacker Cup 2023 Round 1</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/.Danet\" title=\"Expert .Danet\" class=\"rated-user user-blue\">.Danet</a> →\r\n <a href=\"/blog/entry/121172\">[TLE on pretest1]</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\" class=\"rated-user user-red\">Pyqe</a> →\r\n <a href=\"/blog/entry/121025\">Codeforces Round #902 (Div. 1, Div. 2, based on COMPFEST 15 — Final Round)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pranshu_Pandya\" title=\"Specialist Pranshu_Pandya\" class=\"rated-user user-cyan\">Pranshu_Pandya</a> →\r\n <a href=\"/blog/entry/121171\">An Interesting Tree Problem</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/sszcdjr\" title=\"Master sszcdjr\" class=\"rated-user user-orange\">sszcdjr</a> →\r\n <a href=\"/blog/entry/119859\">Codeforces Round 896 (Div. 1, Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/119880\">It's Happening! Meta Hacker Cup 2023 Schedule</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/DaviddeGea1\" title=\"Expert DaviddeGea1\" class=\"rated-user user-blue\">DaviddeGea1</a> →\r\n <a href=\"/blog/entry/70917\">Number of ways of dividing an array into 2 parts such that sum of each part is > k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bekh\" title=\"Master Bekh\" class=\"rated-user user-orange\">Bekh</a> →\r\n <a href=\"/blog/entry/74245\">Questions and doubts regarding Aliens DP trick</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a> →\r\n <a href=\"/blog/entry/8192\">Codeforces Round #190 — Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/hocky\" title=\"Candidate Master hocky\" class=\"rated-user user-violet\">hocky</a> →\r\n <a href=\"/blog/entry/95323\">FBHC wuining uw Day? Incwease uw stacc size! (ㅅ´ ˘ `)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/liouzhou_101\" title=\"International Master liouzhou_101\" class=\"rated-user user-orange\">liouzhou_101</a> →\r\n <a href=\"/blog/entry/87598\">Editorial of Codeforces Round #700</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/yeon_gist\" title=\"Newbie yeon_gist\" class=\"rated-user user-gray\">yeon_gist</a> →\r\n <a href=\"/blog/entry/121170\">plusMinusPermutation computing error</a>\r\n <img alt=\"Text created or updated\" title=\"Text created or updated\" src=\"//codeforces.org/s/81027/images/icons/x-update-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/altforminuscontribution\" title=\"Newbie altforminuscontribution\" class=\"rated-user user-gray\">altforminuscontribution</a> →\r\n <a href=\"/blog/entry/121162\">My screen get unexpectedly big, what should I do</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/atcoder_official\" title=\"Unrated, atcoder_official\" class=\"rated-user user-black\">atcoder_official</a> →\r\n <a href=\"/blog/entry/121120\">We will hold UNIQUE VISION Programming Contest 2023 Autumn(AtCoder Beginner Contest 323)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/YouStill_DontKnowMeYet\" title=\"Candidate Master YouStill_DontKnowMeYet\" class=\"rated-user user-violet\">YouStill_DontKnowMeYet</a> →\r\n <a href=\"/blog/entry/117659\">[GYM] Al-Baath Collegiate Programming Contest 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/ankancool\" title=\"Expert ankancool\" class=\"rated-user user-blue\">ankancool</a> →\r\n <a href=\"/blog/entry/121136\">Invitation to AstroByte 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/GeZhiyuan\" title=\"Grandmaster GeZhiyuan\" class=\"rated-user user-red\">GeZhiyuan</a> →\r\n <a href=\"/blog/entry/120943\">Codeforces Round 901 (Div. 1, Div. 2) Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a> →\r\n <a href=\"/blog/entry/120772\">PSA: Increase your stack size before the Meta Hacker Cup, here's how</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/dino_merlin\" title=\"Expert dino_merlin\" class=\"rated-user user-blue\">dino_merlin</a> →\r\n <a href=\"/blog/entry/121145\">Intuitive approach for CEOI Kangaroo?</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/icecuber\" title=\"Grandmaster icecuber\" class=\"rated-user user-red\">icecuber</a> →\r\n <a href=\"/blog/entry/70018\">CSES DP section editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bn00b\" title=\"Newbie Bn00b\" class=\"rated-user user-gray\">Bn00b</a> →\r\n <a href=\"/blog/entry/98820\">[FEATURE REQUEST : ATCODER] TOPICS TAGS AND SORTING BY SOLVE COUNT</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a> →\r\n <a href=\"/blog/entry/121163\">AtCoder Regular Contest 166 Announcement</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/windva\" title=\"Grandmaster windva\" class=\"rated-user user-red\">windva</a> →\r\n <a href=\"/blog/entry/120644\">Codeforces Round 899 (Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Misa-Misa\" title=\"Expert Misa-Misa\" class=\"rated-user user-blue\">Misa-Misa</a> →\r\n <a href=\"/blog/entry/121157\">Someone please help me understand this.</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/shivam565\" title=\"Specialist shivam565\" class=\"rated-user user-cyan\">shivam565</a> →\r\n <a href=\"/blog/entry/108348\">Total number of subarrays with sum atmost k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n </ul>\r\n </div>\r\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/recent-actions\">Detailed →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n</div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li><a\r\n href=\"/profile/cgy4ever\">cgy4ever</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/cgy4ever\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/cgy4ever\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/cgy4ever\">Submissions</a></li>\r\n <li><a\r\n href=\"/groups/with/cgy4ever\">Groups</a></li>\r\n <li><a\r\n href=\"/contests/with/cgy4ever\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/cgy4ever\">Problemsetting</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/cgy4ever\" style=\"text-decoration:none;color:black !important;\">cgy4ever's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"10684\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/10629\"> <p>Codeforces Round #228 — Editorial</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a>,\r\n <span class=\"format-humantime\" title=\"Feb/03/2014 22:14\">10 years ago</span>,\r\n \r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p>You can find the editorial and my solutions here: <a href=\"https://github.com/cgy4ever/CF228\">https://github.com/cgy4ever/CF228</a></p><p><a href=\"/contest/389/problem/A\" title=\"Codeforces Round 228 (Div. 2)\">389A - Fox and Number Game</a></p><p>First we know that: in the optimal solution, all number will be equal: otherwise we can pick a and b (a < b) then do b = b — a, it will make the answer better.</p><p>Then we need an observation: after each operation, the GCD (Greatest common divisor) of all number will remain same. It can be proved by this lemma: if g is a divisor of all number of x[], then after the operation, g is still the divisor of these numbers, and vice versa.</p><p>So in the end, all number will become the GCD of x[].</p><p>Another solution that can pass is: While there exist x[i] > x[j], then do x[i] -= x[j]. We can select arbitrary i and j if there exist more than 1 choice.</p><p><a href=\"/contest/389/problem/B\" title=\"Codeforces Round 228 (Div. 2)\">389B - Fox and Cross</a></p><p>Let's define the first # of a shape is the cell contain # that have the lexicographical smallest coordinate. Then the first # of a cross is the top one.</p><p>Then let x be the first # of the given board. (If the board is empty, then we can draw it with zero crosses.) x must be covered by a cross, and x must be the first # of the cross. (You can try 4 other positions, it will cause a lexicographical smaller # in the board than x)</p><p>So we try to cover this x use one cross, if it leads some part of the cross covers a '.', then there will be no solution. If not, we just reduce the number of # in the board by 4, we can do this again and again.</p><p><a href=\"/contest/389/problem/C\" title=\"Codeforces Round 228 (Div. 2)\">389C - Fox and Box Accumulation</a> / <a href=\"/contest/388/problem/A\" title=\"Codeforces Round 228 (Div. 1)\">388A - Fox and Box Accumulation</a></p><p>We need some observation:</p> <ol> <li><p>There exists an optimal solution such that: in any pile, the box on the higher position will have a smaller strength.</p></li> <li><p>Let k be the minimal number of piles, then there exists an optimal solution such that: The height of all piles is n/k or n/k+1 (if n%k=0, then all of them have the height n/k).</p></li> </ol><p>We can prove them by exchange argument: from an optimal solution, swap the boxes in it to make above property holds, and we can ensure it will remain valid while swapping.</p><p>Then for a given k, we can check whether there exist a solution: the i-th (indexed from 0) smallest strength needs to be at least i/k.</p><p>So we can do binary search (or just enumerate, since n is only 100) on k.</p><p><a href=\"/contest/389/problem/D\" title=\"Codeforces Round 228 (Div. 2)\">389D - Fox and Minimal path</a> / <a href=\"/contest/388/problem/B\" title=\"Codeforces Round 228 (Div. 1)\">388B - Fox and Minimal path</a></p><p>First we need to know how to calculate the number of different shortest paths from vertex 1 to vertex 2: it can be done by dp: dp[1] = 1, dp[v] = sum{dp[t] | dist(1,t) = dist(1,v) — 1}, then dp[2] is our answer.</p><p>We need to do dp layer by layer. (first we consider vertexes have distance 1 to node 1, then vertexes have distance 2 to node 1 and so on.) So we can construct the graph layer by layer, and link edges to control the dp value of it.</p><p>My solution is construct the answer by binary express: If k is 19, then we need some vertexes in previous layer such that the dp value is 16, 2 and 1. So we just need a way to construct layer with dp value equals to 2^k.</p><p>In the first layer, it contains one node: 1, it has the dp value 1. In the next layer, we can construct 2 nodes, with dp value equals to 1. (We use [1 1] to denote it). And the next layer is [1 1 2], then [1 1 2 4], [1 1 2 4 8] and so on. So we need about 30 layers such that gets all 2^k where k < 30. It uses about 500 nodes.</p><p><a href=\"/contest/389/problem/E\" title=\"Codeforces Round 228 (Div. 2)\">389E - Fox and Card Game</a> / <a href=\"/contest/388/problem/C\" title=\"Codeforces Round 228 (Div. 1)\">388C - Fox and Card Game</a></p><p>First let's consider the case which all piles have even size. In this case, we can prove: in the optimal play, Ciel will gets all top most half cards of each pile, and Jiro gets the remain cards.</p><p>We can prove by these facts: Ciel have a strategy to ensure she can get this outcome and Jiro also have a strategy to ensure this outcome. (For Jiro this strategy is easy: just pick the card from pile that Ciel have just picked. For Ciel it's a little bit harder.)</p><p>Why we can conclude they are both the optimal strategy? Ciel just can't win more, because if she played with Jiro with above strategy, Jiro will get the bottom half of each pile.</p><p>Then we come back with cases that contain odd size piles. The result is: for odd size pile, Ciel will get the top (s-1)/2 cards and Jiro will get the bottom (s-1)/2 cards. Then what about the middle one? Let's denote S is all such middle cards. Then we define a reduced game: In each turn, they pick one card from S. The optimal play for this game is easy: Ciel gets the max one, and Jiro gets the 2nd largest one, and Ciel gets the 3rd largest one and so on.</p><p>We can prove Ciel have a strategy to get: all top half parts + cards she will get in the optimal play in the reduced game. And Jiro also have a strategy to get: all bottom half parts + cards he will get in the optimal play in the reduced game. And these strategy are optimal.</p><p><a href=\"/contest/388/problem/D\" title=\"Codeforces Round 228 (Div. 1)\">388D - Fox and Perfect Sets</a></p><p>A perfect set correspond to a linear space, so we can use base to represent it. We do the Gauss–Jordan elimination of vectors in that set, and can get an unique base. (Note that we need to to the all process of Gauss–Jordan elimination, including the elimination after it reached upper triangular)</p><p>And we can construct the bases bit by bit from higher bit to lower, for a bit:</p> <ol> <li><p>We can add a vector to the base such that the bit is the highest bit of that vector. And at this time, all other vector will have 0 in this bit.</p></li> <li><p>Otherwise we need to assign this bit of each vector already in the base. If now we have k vector, then we have 2^k choices.</p></li> </ol><p>And when we do this, we need to know what's the maximal vector in this space. It's not hard:</p> <ol> <li><p>If we add a vector, then in the maximal vector, this bit will be 1.</p></li> <li><p>Otherwise, if we don't have any vector in base yet, then this bit will be 0. Otherwise there will be 2^(k-1) choices results in this bit of maximal vector will be 0, and 2^(k-1) choices results in 1.</p></li> </ol><p>So we can solve this task by DP bit by bit.</p><p><a href=\"/contest/388/problem/E\" title=\"Codeforces Round 228 (Div. 1)\">388E - Fox and Meteor Shower</a></p><p>All tasks beside this are very easy to code. And this one focus on implementation.</p><p>We can represent the orbit of each meteor by a line in 3D space. (we use an axis to represent the time, and two axis to represent the position on the plane.)</p><p>Then the problem becomes: we have some lines in 3D space (they are not complete coincide), find a largest clique such that each pair of lines touch at some point.</p><p>We need this observation: If there are 3 lines in the optimal clique, and these 3 lines are not share a common point, then all line in this clique will on a plane.</p><p>By using this observation, we only need to consider 2 cases:</p> <ol> <li><p>All lines in the clique have a common point.</p></li> <li><p>All lines in the clique are on the same plane.</p></li> </ol><p>Both are easy tasks in theory, but it needs some coding.</p><p>There are two ways:</p> <ol> <li><p>Use integer anywhere. Note that the coordinates of intersection can be rational number, but can't be irrational, so we could do this. We can use some way to encode the plane, direction.</p></li> <li><p>Use floating number. To count same number of points, we can sort (x, y, z) by using the following compare function: if (abs(A.x — B.x) > eps){return A.x < B.x} otherwise { if(abs(A.y-B.y)>eps){return A.y < B.y} otherwise return A.z < B.z}.</p></li> </ol></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/388\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 228 (Div. 1)</a> </span>\r\n </div>\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/389\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 228 (Div. 2)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-21-10684\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"21\",\n blogEntryId: \"10629\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-10684\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+45</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-10684\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/cgy4ever\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/cgy4ever\">\n cgy4ever\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Feb/03/2014 22:14\">10 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/10629#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/10629#comments\">\n 44\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"10700\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (39)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159842\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/YaleZ\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/24526/avatar/5b17db1affad55a5.jpg'/> </a>\n <div><a href=\"/profile/YaleZ\" title=\"Expert YaleZ\" class=\"rated-user user-blue\">YaleZ</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2014 22:38\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159842\" href=\"?#comment-159842\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"159842\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"159842\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"24526\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159842\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thank for timely editorial. I think Markdown is better when publish something on Github. Isn't it?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159842 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159842 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159842\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159846\" commentParentId=\"159842\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/cgy4ever\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2014 22:43\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159846\" href=\"?#comment-159846\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159842\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159846\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"11\"\r\n data-commentUserId=\"62\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+11</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159846\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Yes, I'm working on it. :)</p><p>The website seems to be not stable at this time. So I post them in other sites to ensure all people can see it.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159846 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159846 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159846\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159857\" commentParentId=\"159846\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Nodir.Daminov\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/71439/avatar/d6d2016f6dfe5ecd.jpg'/> </a>\n <div><a href=\"/profile/Nodir.Daminov\" title=\"Candidate Master Nodir.Daminov\" class=\"rated-user user-violet\">Nodir.Daminov</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2014 22:58\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159857\" href=\"?#comment-159857\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159846\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159857\" class=\"CommentVoteFrame\"\r\n class=\"too-negative-comment-vote\"\r\n data-commentRating=\"-35\"\r\n data-commentUserId=\"71439\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-35</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159857\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Maaan is it so hard to COPY ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159857 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159857 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159857\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159874\" commentParentId=\"159857\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/cgy4ever\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2014 23:19\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159874\" href=\"?#comment-159874\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159857\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159874\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"12\"\r\n data-commentUserId=\"62\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+12</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159874\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Sorry for the delay.</p><p>When I was submitting my post that contains the editorial, it always returns "Codeforces is now unavailable." so I just can't post it.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159874 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159874 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159874\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159859\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/BishalG\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/60637/avatar/d21ddf49bbd1630c.jpg'/> </a>\n <div><a href=\"/profile/BishalG\" title=\"Expert BishalG\" class=\"rated-user user-blue\">BishalG</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2014 22:58\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159859\" href=\"?#comment-159859\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159859\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"60637\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159859\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Nice problemSets @<a class=\"rated-user user-orange\" href=\"/profile/cgy4ever\" title=\"International Master cgy4ever\">cgy4ever</a> , although I misunderstood the problem-B <a href=\"/contest/389/problem/B\" title=\"Codeforces Round 228 (Div. 2)\">389B - Fox and Cross</a> upto 1 hrs :( </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159859 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159859 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159859\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159867\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Mr.ink\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Mr.ink\" title=\"Expert Mr.ink\" class=\"rated-user user-blue\">Mr.ink</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2014 23:07\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159867\" href=\"?#comment-159867\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159867\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"128876\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159867\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>due to my slow internet speed i can not see your editorial on github because my country internet has problem with https! </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159867 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159867 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159867\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159881\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Mr.ink\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Mr.ink\" title=\"Expert Mr.ink\" class=\"rated-user user-blue\">Mr.ink</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2014 23:38\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159881\" href=\"?#comment-159881\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159881\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"128876\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159881\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>does anyone have a better solution for div2 C problem?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159881 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159881 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159881\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159883\" commentParentId=\"159881\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/t_thirupathi\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/146179/avatar/98c28348196ce4ca.jpg'/> </a>\n <div><a href=\"/profile/t_thirupathi\" title=\"Specialist t_thirupathi\" class=\"rated-user user-cyan\">t_thirupathi</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2014 23:42\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159883\" href=\"?#comment-159883\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159881\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159883\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"146179\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159883\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Have a look at mine <a href=\"/contest/389/submission/5878414\" title=\"Submission 5878414 by t_thirupathi\">5878414</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159883 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159883 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159883\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159909\" commentParentId=\"159883\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/9charles\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/119814/avatar/653156a3153bc2dd.jpg'/> </a>\n <div><a href=\"/profile/9charles\" title=\"Expert 9charles\" class=\"rated-user user-blue\">9charles</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 06:46\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159909\" href=\"?#comment-159909\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159883\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159909\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"119814\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159909\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can you explain it?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159909 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159909 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159909\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159907\" commentParentId=\"159881\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/k790alex\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/119882/avatar/4baeddca65b2b958.jpg'/> </a>\n <div><a href=\"/profile/k790alex\" title=\"Specialist k790alex\" class=\"rated-user user-cyan\">k790alex</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 06:28\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159907\" href=\"?#comment-159907\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159881\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159907\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"119882\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159907\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I don't know if this is a better way but I didt in the contest.</p><p>Start making a pile with the low strength and while possible, look for a box that can support at least 1 box, then at least 2 boxes, 3, etc, repeat it while you have boxes.</p><p>My solution: <a href=\"/contest/389/submission/5879464\" title=\"Submission 5879464 by k790alex\">5879464</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159907 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159907 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159907\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159914\" commentParentId=\"159907\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/YaleZ\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/24526/avatar/5b17db1affad55a5.jpg'/> </a>\n <div><a href=\"/profile/YaleZ\" title=\"Expert YaleZ\" class=\"rated-user user-blue\">YaleZ</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 07:38\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159914\" href=\"?#comment-159914\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159907\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159914\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"24526\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159914\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Greedy is also a nice solution.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159914 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159914 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159914\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159932\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/worfzyq\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/157364/avatar/8f104a361ed91be8.jpg'/> </a>\n <div><a href=\"/profile/worfzyq\" title=\"Expert worfzyq\" class=\"rated-user user-blue\">worfzyq</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 09:52\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159932\" href=\"?#comment-159932\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159932\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"157364\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159932\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>388C — Fox and Card Game This problem is good magic</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159932 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159932 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159932\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159935\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/orchidmajumder\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/63603/avatar/f8db3747466a7168.jpg'/> </a>\n <div><a href=\"/profile/orchidmajumder\" title=\"Specialist orchidmajumder\" class=\"rated-user user-cyan\">orchidmajumder</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 10:07\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159935\" href=\"?#comment-159935\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"159935\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"159935\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"7\"\r\n data-commentUserId=\"63603\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+7</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159935\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>hii everyone,in Div II E,I can't understand why the optimal play for JIRO is to take the bottom most card from the same pile from where CIEL is picking?should not it try to pick the maximum value among all bottom most card at it's every move??</p><p>Please someone explain why the strategy presented in the editorial is optimal.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159935 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159935 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159935\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159948\" commentParentId=\"159935\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Zzyzx\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/86049/avatar/c698ee674460e7eb.jpg'/> </a>\n <div><a href=\"/profile/Zzyzx\" title=\"Expert Zzyzx\" class=\"rated-user user-blue\">Zzyzx</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 13:07\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159948\" href=\"?#comment-159948\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159935\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159948\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"86049\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159948\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Ok, I'm afraid I do not have a rigorous proof for this. I'll just explain to you why I think it is right.</p><p>First of all, we need to understand that both Ciel and Jiro are smart. Now, whenever it is Ciel's turn, he will pick the "best pile" and try to take everything from that pile and then move on to the next "best pile". Jiro knows that his friend Ciel is smart, so he will try to stop him from taking everything. This can be done only if he picks from the same pile that Ciel does.</p><p>But your question is — what if there is a different pile whose bottom-most card is much better than the bottom-most card of the pile from which Ciel is picking right?</p><p>My answer to this is that, this situation will never arise. Because if there is such a pile, then Ciel will try to take that card in the first place and therefore, Ciel will be picking from the same pile that Jiro will want to pick from.</p><p>Am I making sense? Or is there a flaw in my argument?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159948 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159948 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159948\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159952\" commentParentId=\"159948\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/orchidmajumder\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/63603/avatar/f8db3747466a7168.jpg'/> </a>\n <div><a href=\"/profile/orchidmajumder\" title=\"Specialist orchidmajumder\" class=\"rated-user user-cyan\">orchidmajumder</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 13:32\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159952\" href=\"?#comment-159952\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159948\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159952\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"63603\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159952\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Yes I'm also thinking along the same line.Both are playing optimally and if Ciel is chosing any pile then jiro knows that this pile has better cards in the botttom half.So he won't choose ciel to take the advantage and vice versa.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159952 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159952 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159952\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159944\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hzyfr\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/hzyfr\" title=\"Expert hzyfr\" class=\"rated-user user-blue\">hzyfr</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 12:27\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159944\" href=\"?#comment-159944\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159944\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"129936\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159944\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I have a different idea on D div1 <a href=\"/contest/388/problem/D\" title=\"Codeforces Round 228 (Div. 1)\">388D - Fox and Perfect Sets</a> but I failed on getting some relations in one step.</p><p>Let <em>M</em> be the maximum element in set <em>S</em> . Then if <em>S</em> is a perfect set, its elements should have all bits equals <em>0</em> on positions in <em>M's</em> binary representation(otherwise there must exist another element bigger than <em>M</em>). So let <em>cnt</em> = (number of 1's in binary repersentation of <em>M</em>), then the number of perfect sets which has <em>M</em> as its greatest element is determined by <em>cnt</em> . Well, this is the step I can't come up with a solution(actually the target is to find the number of perfect sets which has <code>2^cnt-1</code> as its greatest element).</p><p>Then the last step is simple. We can apply something like doubling algorithm on the problem.</p><p>We are asked to find the number of perfect sets with all the elements not greater than <em>N</em> . Let's suppose <em>N+1</em> is a power of 2 then its easy to calculate how many numbers not greater than <em>N</em> has <em>cnt</em> = 1,2,...m where m is the length of <em>N</em> in binary representation. That's just simple combinatoric number <em>C(n,i) (1<=i<=n)</em> . And if we have done the previous step, it's easy to get the result.</p><p>Then think about common cases of <em>N</em> . Let's take the highest bit of N and since all above bits are determined, the number of 1's will just add a constant value. So calculate this part and subtract that highest bit of <em>N</em> and do the same thing on remaining value of <em>N</em> , until <em>N=0</em> . At that time we will get the correct answer. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159944 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159944 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159944\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159945\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/rexdf\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/23738/avatar/797fa665fbe1ca78.jpg'/> </a>\n <div><a href=\"/profile/rexdf\" title=\"Specialist rexdf\" class=\"rated-user user-cyan\">rexdf</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 12:36\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159945\" href=\"?#comment-159945\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159945\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"23738\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159945\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>dp[1] = 1, dp[v] = sum{dp[t] | dist(1,t) = dist(1,v) — 1}, then dp[2] is our answer. What's v means? what's '|' means? What's dp[v] means?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159945 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159945 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159945\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159949\" commentParentId=\"159945\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/sancho\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/85894/avatar/e31a4b24327c1000.jpg'/> </a>\n <div><a href=\"/profile/sancho\" title=\"Candidate Master sancho\" class=\"rated-user user-violet\">sancho</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 13:10\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159949\" href=\"?#comment-159949\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159945\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159949\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"85894\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159949\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>v — vertex, answer for which we are getting at this moment, | — means "such as", dp[v] — number of ways from 1 vertex to this one</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159949 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159949 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159949\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159947\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lol12\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/lol12\" title=\"Specialist lol12\" class=\"rated-user user-cyan\">lol12</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 13:04\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159947\" href=\"?#comment-159947\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159947\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"10\"\r\n data-commentUserId=\"152356\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+10</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159947\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can someone please explain solution of Div2-D. Thanx</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159947 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159947 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159947\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"160020\" commentParentId=\"159947\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/YaleZ\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/24526/avatar/5b17db1affad55a5.jpg'/> </a>\n <div><a href=\"/profile/YaleZ\" title=\"Expert YaleZ\" class=\"rated-user user-blue\">YaleZ</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/05/2014 07:07\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-160020\" href=\"?#comment-160020\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159947\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"160020\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"9\"\r\n data-commentUserId=\"24526\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+9</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-160020\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>You can think about binnary. Such as (13)10=(1101)2=((1+(2+0)*2)+1)*2+1</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-160020 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-160020 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-160020\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"469976\" commentParentId=\"159947\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/roll_no_1\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/631859/avatar/36d157f91f64fe7f.jpg'/> </a>\n <div><a href=\"/profile/roll_no_1\" title=\"Master roll_no_1\" class=\"rated-user user-orange\">roll_no_1</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Nov/09/2018 17:27\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-469976\" href=\"?#comment-469976\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159947\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"469976\" revisionCount=\"4\" revision=\"4\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">4</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"469976\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"631859\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-469976\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Here's my implementation of the editorialist's explanation of Div-2 D / Div-1 B: <a href=\"/contest/388/submission/45480077\" title=\"Submission 45480077 by roll_no_1\">45480077</a>. I implemented the layers as [1], [1, 1], [2, 1, 1], [4, 2, 1, 1] and so on.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-469976 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-469976 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-469976\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159967\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/BENYAM1N\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/84938/avatar/d2ae2657d8898e38.jpg'/> </a>\n <div><a href=\"/profile/BENYAM1N\" title=\"Master BENYAM1N\" class=\"rated-user user-orange\">BENYAM1N</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 15:51\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159967\" href=\"?#comment-159967\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159967\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"13\"\r\n data-commentUserId=\"84938\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+13</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159967\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Very good contest and nice editorial. Hope from now on I see more contests from you.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159967 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159967 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159967\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159984\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/kojak_\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/57722/avatar/38990eea59bc188e.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/kojak_\" title=\"Newbie kojak_\" class=\"rated-user user-gray\">kojak_</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 18:34\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159984\" href=\"?#comment-159984\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159984\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"57722\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159984\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Did anyone come up with a DP solution for Div.2 C/ Div.1 A?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159984 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159984 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159984\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"160012\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/IgorKoval\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/51322/avatar/afc854fff49f072a.jpg'/> </a>\n <div><a href=\"/profile/IgorKoval\" title=\"Candidate Master IgorKoval\" class=\"rated-user user-violet\">IgorKoval</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 23:17\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-160012\" href=\"?#comment-160012\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"160012\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"11\"\r\n data-commentUserId=\"51322\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+11</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-160012\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Объясните, пожалуйста, разбор задачи "388D — Fox and Perfect Sets" на пальцах. Как-нибудь без Гаусса и базисов. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-160012 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-160012 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-160012\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"160016\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Mr.ink\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Mr.ink\" title=\"Expert Mr.ink\" class=\"rated-user user-blue\">Mr.ink</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/05/2014 01:08\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-160016\" href=\"?#comment-160016\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"160016\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"128876\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-160016\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>fox and card games is a great problem.thanks!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-160016 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-160016 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-160016\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"160037\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/yaswanth\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/yaswanth\" title=\"Specialist yaswanth\" class=\"rated-user user-cyan\">yaswanth</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/05/2014 18:38\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-160037\" href=\"?#comment-160037\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"160037\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"9\"\r\n data-commentUserId=\"96196\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+9</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-160037\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can anyone explain div2 C question? I did not understand the editorial.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-160037 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-160037 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-160037\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"160063\" commentParentId=\"160037\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/YaleZ\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/24526/avatar/5b17db1affad55a5.jpg'/> </a>\n <div><a href=\"/profile/YaleZ\" title=\"Expert YaleZ\" class=\"rated-user user-blue\">YaleZ</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/06/2014 05:46\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-160063\" href=\"?#comment-160063\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-160037\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"160063\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"24526\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-160063\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>s[i]>=i/k -> k*s[i]>=i There are i boxes' strength smaller than i-th box. So we need to check if the boxes before i-th can be held.</p><p>(I don't know whether I have understood correctly...)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-160063 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-160063 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-160063\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"160053\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/yada\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/142663/avatar/49901b54d1c5f019.jpg'/> </a>\n <div><a href=\"/profile/yada\" title=\"Candidate Master yada\" class=\"rated-user user-violet\">yada</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/05/2014 23:24\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-160053\" href=\"?#comment-160053\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"160053\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"142663\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-160053\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Great Problem! I really enjoy it.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-160053 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-160053 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-160053\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"364019\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lnzva\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/305672/avatar/cf6c09a214141751.jpg'/> </a>\n <div><a href=\"/profile/lnzva\" title=\"Expert lnzva\" class=\"rated-user user-blue\">lnzva</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/02/2017 22:06\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-364019\" href=\"?#comment-364019\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"364019\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"364019\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"305672\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-364019\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In 388C, I'm having a hard time understanding why Jiro's optimal strategy would be to pick the pile Ciel just picked. Why not pick a pile which has a better bottom part than the one Ciel is picking? According to some comments, Ciel would then pick from the second pile-what if another pile has a much better top part? Could someone please help? I saw this problem first 6 months ago, and I had a hard time understanding why this greedy is correct; I saw this problem again today and am having trouble with it again, with no progress.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-364019 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-364019 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-364019\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"647866\" commentParentId=\"364019\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/_wzx27\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1458283/avatar/7d77b62012ae2398.jpg'/> </a>\n <div><a href=\"/profile/_wzx27\" title=\"Candidate Master _wzx27\" class=\"rated-user user-violet\">_wzx27</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/22/2020 18:33\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-647866\" href=\"?#comment-647866\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-364019\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"647866\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1458283\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-647866\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Let's consider such a two-piles situation:</p><p><em>111100</em></p><p><em>001111</em></p><p>is better for Ciel.</p><p>"1" means this card is picked by Ciel,while "0" by Jiro.</p><p>We know that better for Ciel means worse for Jiro.</p><p>So if</p><p><em>111100</em></p><p><em>001111</em></p><p>is better than</p><p><em>111000</em></p><p><em>000111</em></p><p>for Ciel.</p><p>Then when Ciel picked the <strong>first three cards</strong> from <strong>pile 1</strong>,Jiro can just pick the <strong>last three cards</strong> from <strong>pile 1</strong> and finally lead to the result:</p><p><em>111000</em></p><p><em>000111</em></p><p>which is not better for Ciel.</p><p>Generally, if the final result is not balance(half from top and half from bottom) while balance is better than such result for Jiro, Jiro has the ability to adjust it to be balance.So do Ciel.</p><p>Therefore,it reaches balance.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-647866 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-647866 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-647866\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"407776\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/madhur4127\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/568692/avatar/c7d62cc23c758819.jpg'/> </a>\n <div><a href=\"/profile/madhur4127\" title=\"Specialist madhur4127\" class=\"rated-user user-cyan\">madhur4127</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/15/2018 13:06\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-407776\" href=\"?#comment-407776\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"407776\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"568692\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-407776\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>@<a class=\"rated-user user-red\" href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\">cgy4ever</a>, github link shows 404 error(Page not found). Kindly fix it.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-407776 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-407776 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-407776\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"416354\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/introverted\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/657339/avatar/7a6edb1ecc1d3e09.jpg'/> </a>\n <div><a href=\"/profile/introverted\" title=\"Expert introverted\" class=\"rated-user user-blue\">introverted</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/23/2018 11:48\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-416354\" href=\"?#comment-416354\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"416354\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"657339\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-416354\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I solved the DIV1B problem with simple recursion and Divide and Conquer.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-416354 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-416354 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-416354\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"427890\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Nuu\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/652228/avatar/d59867d6477379dc.jpg'/> </a>\n <div><a href=\"/profile/Nuu\" title=\"Candidate Master Nuu\" class=\"rated-user user-violet\">Nuu</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/01/2018 22:33\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-427890\" href=\"?#comment-427890\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"427890\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"652228\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-427890\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can anyone give me some examples of the similar problems to DivC?? I think this problem is very nice for train brain xD</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-427890 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-427890 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-427890\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"629609\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/The_Alchemist\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1275181/avatar/662970aa05d3dfc5.jpg'/> </a>\n <div><a href=\"/profile/The_Alchemist\" title=\"Expert The_Alchemist\" class=\"rated-user user-blue\">The_Alchemist</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/25/2020 21:47\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-629609\" href=\"?#comment-629609\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"629609\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1275181\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-629609\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I know I am very late but can someone pls explain to me div 2C/div1A. Thanks in advance... </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-629609 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-629609 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-629609\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"641010\" commentParentId=\"629609\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/kstheking\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1160931/avatar/e144fc7b0fdb90b1.jpg'/> </a>\n <div><a href=\"/profile/kstheking\" title=\"Pupil kstheking\" class=\"rated-user user-green\">kstheking</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/13/2020 14:47\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-641010\" href=\"?#comment-641010\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-629609\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"641010\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1160931\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-641010\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p><a href=\"https://codeforces.com/contest/388/submission/83605110\">https://codeforces.com/contest/388/submission/83605110</a> Here you go, if you don't get it feel free to ask</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-641010 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-641010 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-641010\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"644488\" commentParentId=\"641010\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/tanisha_\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/tanisha_\" title=\"Newbie tanisha_\" class=\"rated-user user-gray\">tanisha_</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/18/2020 15:26\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-644488\" href=\"?#comment-644488\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-641010\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"644488\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1500127\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-644488\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>is this any algorithm</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-644488 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-644488 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-644488\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"647627\" commentParentId=\"644488\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/kstheking\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1160931/avatar/e144fc7b0fdb90b1.jpg'/> </a>\n <div><a href=\"/profile/kstheking\" title=\"Pupil kstheking\" class=\"rated-user user-green\">kstheking</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/22/2020 08:40\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-647627\" href=\"?#comment-647627\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-644488\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"647627\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"647627\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1160931\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-647627\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Well you can call it a greedy algorithm, when we try to apply greedy by placing the heaviest block in bottom, a little problem occurs because of blocks of same strength for example in case of 10 2 2 1 1 0 0<br />If you try to apply greedy by choosing the strongest block<br />10 2 2 1<br />1 0<br />0<br />= 3 heaps<br />Which is wrong answer as sometimes we lose opportunity to create lesser heaps, as in this case if we use the second 2 to make another heap we can do better<br />10 2 1 0<br />2 1 0<br />= 2 heaps<br />So I apply greedy in the reverse direction by picking the smallest strength brick and placing below it the next smallest brick, this way the optimal number of heaps will be formed as in above example<br />choose 0, then you need >= 1, choose 1, then you need >= 2, choose 2, then you need >= 3 choose 10<br />repeat until you have chosen all the bricks<br />If you don't get anything, feel free to ask :) </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-647627 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-647627 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-647627\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"702677\" commentParentId=\"647627\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/breddreamer\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/853067/avatar/240684624b57996.jpg'/> </a>\n <div><a href=\"/profile/breddreamer\" title=\"Newbie breddreamer\" class=\"rated-user user-gray\">breddreamer</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/27/2020 13:01\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-702677\" href=\"?#comment-702677\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-647627\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"702677\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"853067\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-702677\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks, It helped me to understand your solution idea. And finally, I solved this one.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-702677 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-702677 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-702677\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"649225\" commentParentId=\"641010\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/The_Alchemist\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1275181/avatar/662970aa05d3dfc5.jpg'/> </a>\n <div><a href=\"/profile/The_Alchemist\" title=\"Expert The_Alchemist\" class=\"rated-user user-blue\">The_Alchemist</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/24/2020 12:04\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-649225\" href=\"?#comment-649225\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-641010\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"649225\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1275181\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-649225\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>thank you.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-649225 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-649225 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-649225\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n <br/>\r\n\r\n<div id=\"editBox-10700\" style=\"width:50em;display:none;\">\r\n <div class=\"previewBody\" style=\"border: 1px solid #d4d4d4; margin-bottom: 0.5em; padding: 0.25em; display:none;\"> </div>\r\n <div style=\"width: 1px\"> </div>\r\n <div class=\"commentLocale\" style=\"position: relative; top: 0.5em;left:4px;display: none;\">\r\n <input type=\"radio\" name=\"locale\" value=\"en\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In English</span>\r\n <input style=\"margin-left:1em\" type=\"radio\" name=\"locale\" value=\"ru\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In Russian</span>\r\n </div>\r\n <textarea data-drafts-id=\"CommentReplyFrame\" class=\"wysiwyg\" name=\"editContent\" rows=\"20\" style=\"width:99%;\"></textarea>\r\n <div class=\"error error__content\"></div>\r\n <div style=\"text-align:center;\">\r\n <input type=\"button\" name=\"preview\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Preview\"/>\r\n <input type=\"button\" name=\"save\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Save\"/>\r\n </div>\r\n</div>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n\r\nvar firstPreview10700 = true;\r\nvar lastPreviewContent10700 = '';\r\n\r\nif (!window.moveCommentRevision) {\r\n moveCommentRevision = function(e, dir) {\r\n var p = e.parent();\r\n var revisionCount = parseInt(p.attr(\"revisionCount\"));\r\n var revision = parseInt(p.attr(\"revision\"));\r\n var next = revision + dir;\r\n var commentId = p.attr(\"commentId\");\r\n if (next >= 1 && next <= revisionCount) {\r\n $.post(\r\n \"/data/comment-data\",\r\n {action: \"revision\", commentId: commentId, revision: next},\r\n function(json) {\r\n if (json.success == \"true\") {\r\n var parentDiv = e;\r\n\r\n while (parentDiv !== null && (parentDiv[0].nodeName.toLowerCase() !== \"td\" || !parentDiv.hasClass(\"right\"))) {\r\n parentDiv = parentDiv.parent();\r\n }\r\n\r\n if (parentDiv === null) {\r\n return;\r\n }\r\n\r\n parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\").html(json.content);\r\n Codeforces.setupSpoilers(parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\"));\r\n p.attr(\"revision\", next);\r\n p.find(\"span.revision\").text(next);\r\n if (next == 1) {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"visible\");\r\n }\r\n if (next == revisionCount) {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"visible\");\r\n }\r\n\r\n window.updateTypography();\r\n MathJax.Hub.Typeset();\r\n } else {\r\n alert(e.error);\r\n }\r\n },\r\n \"json\"\r\n );\r\n }\r\n };\r\n}\r\n\r\n$(\"div[commentableId=10700] a.leftRevision\").click(function () {\r\n window.moveCommentRevision($(this), -1);\r\n return false;\r\n});\r\n\r\n$(\"div[commentableId=10700] a.rightRevision\").click(function () {\r\n window.moveCommentRevision($(this), +1);\r\n return false;\r\n});\r\n\r\n\r\n\r\n });\n </script>\n\r\n\r\n <script src=\"//codeforces.org/s/81027/js/swfobject-2.2.min.js\" type=\"text/javascript\"></script>\n <script src=\"//codeforces.org/s/81027/js/ftaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n if (window.evercookie) {\n var ec = new evercookie({\n history: false,\n silverlight: false,\n baseurl: '',\n asseturi: '/assets',\n phpuri: '/2fdcd78',\n pngPath: '/eps',\n etagPath: '/ees',\n cachePath: '/ecs'\n });\n\n var randomNumber = function () {\n return Math.random().toString(36).substr(2);\n };\n\n var randomToken = function () {\n return (randomNumber() + randomNumber()).substring(0, 18);\n };\n\n window._ftaa = \"\";\n\n ec.get(\"70a7c28f3de\", function (value) {\n window._ftaa = value;\n if (!window._ftaa) {\n window._ftaa = randomToken();\n ec.set(\"70a7c28f3de\", window._ftaa);\n }\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n } else {\n window._ftaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\n <script src=\"//codeforces.org/s/81027/js/bfaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n var fpCallback = function() {\n Fingerprint2.get({}, function(components) {\n window._bfaa = Fingerprint2.x64hash128(components.map(function (pair) { return pair.value }).join(), 31);\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n };\n if (typeof Fingerprint2 !== 'undefined') {\n if (window.requestIdleCallback) {\n requestIdleCallback(fpCallback)\n } else {\n setTimeout(fpCallback, 500)\n }\n } else {\n window._bfaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"a.new-root-comment\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n\r\n $(\".comment-table .reply a\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".vote-for-comment\").mouseover(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").mouseout(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").click(function () {\r\n var vote = $(this);\r\n var commentId = $(this).parent().attr(\"commentid\");\r\n var commentRating = $(this).parent().attr(\"data-commentRating\");\r\n var direction = $(this).attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n $.post(\"/data/comment/vote\", {commentId: commentId, _tta: Codeforces.tta(), vote: direction, commentRating: commentRating}, function(data) {\r\n if (direction != 0 && !ownComment && data[\"success\"] == \"true\") {\r\n vote.parent().find(\".vote-for-comment\").attr(\"voteDirection\", 0);\r\n if (direction == 1)\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n else {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.closest(\".CommentVoteFrame\").find(\".ComplaintFrame\").css(\"display\", \"inline-block\");\r\n }\r\n vote.find(\"img\").attr(\"popacity\", \"1.0\");\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n vote.parent().find(\".commentRating\").html(data[\"commentRating\"]);\r\n }\r\n Codeforces.showMessage(data[\"message\"]);\r\n }, \"json\");\r\n return false;\r\n });\r\n\r\n $(\".negative-comment-vote\").closest(\".comment-table\").addClass(\"comment-bad\");\r\n\r\n $(\".troll-comment-vote\").closest(\".comment\").css(\"display\", \"none\");\r\n\r\n $(\".too-negative-comment-vote\").closest(\".comment-table\").each(function () {\r\n var e = $(this);\r\n e.addClass(\"comment-too-bad\");\r\n var commentId = e.attr(\"commentId\");\r\n $(\"<div class='bad-comment-replacement ttypography'>The comment is hidden because of too negative feedback, click <a href=# class=show-bad-comment-link>here</a> to view it</div>\").appendTo(\r\n e.find(\".right\")\r\n );\r\n e.find(\".comment-content\").hide();\r\n e.find(\".show-bad-comment-link\").click(function () {\r\n e.find(\".comment-content\").show();\r\n e.find(\".bad-comment-replacement\").hide();\r\n return false;\r\n });\r\n });\r\n });\n </script>\n </div>\r\n\r\n <style type=\"text/css\">\r\n .new-comments-box {\r\n padding: 0.5em;\r\n width: 22px;\r\n font-size: 1.3rem;\r\n font-weight: bold !important;\r\n\r\n position: fixed;\r\n top: 40%;\r\n right: 0;\r\n opacity: 0.2;\r\n color: white;\r\n text-align: center;\r\n\r\n border: 1px solid #222;\r\n background-color: #888 !important;\r\n border-radius: 3px;\r\n -moz-border-radius: 3px;\r\n -webkit-border-radius: 3px;\r\n }\r\n\r\n .new-comments-box:hover {\r\n opacity: 1;\r\n }\r\n\r\n .new-comments-box .dir:hover {\r\n background: #3B5998 !important;\r\n cursor: pointer;\r\n }\r\n </style>\r\n\r\n <div class=\"new-comments-box\" data-position=\"outside\" data-index=\"-1\" style=\"display: none;\">\r\n <div class=\"up dir\" title=\"Ctrl+Up\">↑<hr/>\r\n </div>\r\n <div class=\"info\" title=\"New comments\"></div>\r\n <div class=\"down dir\" title=\"Ctrl+Down\">\r\n <hr/>↓\r\n </div>\r\n </div>\r\n\r\n <script>\r\n $(\".show-archived-checkbox\").change(function () {\r\n const checked = $(this).is(\":checked\");\r\n $.post(\"/data/comment-data\", {action: \"setShowArchived\", checked}, function (json) {\r\n if (json[\"success\"] !== \"true\") {\r\n alert(json[\"error\"]);\r\n } else {\r\n if (checked) {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are now displayed\")\r\n } else {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are no longer displayed\")\r\n }\r\n }\r\n });\r\n return false;\r\n });\r\n\r\n function gotoComment(direction) {\r\n var box = $(\".new-comments-box\");\r\n var index = parseInt(box.attr(\"data-index\"));\r\n if (index == -1)\r\n index = 0;\r\n else\r\n index = Math.max(0, Math.min(parseInt(box.find(\".info\").text()) - 1, index + direction));\r\n box.attr(\"data-index\", index);\r\n var comment = $($(\".comment .highlight-blue[commentId]\").get(index));\r\n $('html, body').animate({\r\n 'scrollTop': Math.max(0, comment.offset().top - ($(window).height() - comment.height()) / 2)\r\n });\r\n return false;\r\n }\r\n\r\n $(\".new-comments-box .down\").click(function () {\r\n return gotoComment(1);\r\n });\r\n\r\n $(\".new-comments-box .up\").click(function () {\r\n return gotoComment(-1);\r\n });\r\n\r\n $(document).keydown(function (e) {\r\n var code = (e.keyCode ? e.keyCode : e.which);\r\n if (e.ctrlKey) {\r\n if (code == 38 || code == 40) {\r\n gotoComment(code - 39);\r\n }\r\n }\r\n });\r\n\r\n var newCommentCount = $(\".comment .highlight-blue[commentId]\").length;\r\n if (newCommentCount > 0) {\r\n $(\".new-comments-box .info\").text(newCommentCount);\r\n $(\".new-comments-box\").show();\r\n }\r\n\r\n $('table.comment-table').mouseenter(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").addClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n\r\n $('table.comment-table').mouseleave(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").removeClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n </script>\r\n\r\n\r\n\r\n <script>\r\n function adjustTopicComplainFrames() {\r\n let topicIds = [];\r\n\r\n $(\".has-topic-id\").each(function () {\r\n const $this = $(this);\r\n const topicId = $this.attr(\"topicId\");\r\n if (topicId) {\r\n topicIds.push(topicId);\r\n }\r\n });\r\n\r\n $.post(\"/data/topics\", {\r\n action: \"findComplainableTopicIds\",\r\n topicIds: topicIds.join(\",\")\r\n }, function (json) {\r\n if (json[\"success\"] === \"true\") {\r\n for (const topicId of json[\"complainableTopicIds\"].split(\",\")) {\r\n $(\".has-topic-id[topicId=\" + topicId + \"]\").each(function () {\r\n $(this).find(\".meta .ComplaintFrame\").css(\"display\", \"inline-block\");\r\n });\r\n }\r\n }\r\n }, \"json\");\r\n }\r\n\r\n $(function () {\r\n adjustTopicComplainFrames();\r\n })\r\n </script>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-10684\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 10684, _tta: Codeforces.tta(), topicRevisionId: 36670, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-10684\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 10684, _tta: Codeforces.tta(), topicRevisionId: 36670, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n </div>\r\n </div>\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 22:13:07</span> (h1).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/81027/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/81027/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/81027/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/81027/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-81027.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'812875a2ab4016f4',t:'MTY5NjcwNTk4Ny4yMjQwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"}}},{"rowIdx":1959,"cells":{"problem_id":{"kind":"string","value":"388B"},"contest":{"kind":"string","value":"388"},"problem":{"kind":"string","value":"B"},"lang":{"kind":"string","value":"en"},"problem_title":{"kind":"string","value":"B. Fox and Minimal path"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">B. Fox and Minimal path</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Fox Ciel wants to write a task for a programming contest. The task is: \"You are given a simple undirected graph with <span class=\"tex-span\"><i>n</i></span> vertexes. Each its edge has unit length. You should calculate the number of shortest paths between vertex 1 and vertex 2.\"</p><p>Same with some writers, she wants to make an example with some certain output: for example, her birthday or the number of her boyfriend. Can you help her to make a test case with answer equal exactly to <span class=\"tex-span\"><i>k</i></span>?</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains a single integer <span class=\"tex-span\"><i>k</i></span> (<span class=\"tex-span\">1 ≤ <i>k</i> ≤ 10<sup class=\"upper-index\">9</sup></span>).</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>You should output a graph <span class=\"tex-span\"><i>G</i></span> with <span class=\"tex-span\"><i>n</i></span> vertexes (<span class=\"tex-span\">2 ≤ <i>n</i> ≤ 1000</span>). There must be exactly <span class=\"tex-span\"><i>k</i></span> shortest paths between vertex 1 and vertex 2 of the graph.</p><p>The first line must contain an integer <span class=\"tex-span\"><i>n</i></span>. Then adjacency matrix <span class=\"tex-span\"><i>G</i></span> with <span class=\"tex-span\"><i>n</i></span> rows and <span class=\"tex-span\"><i>n</i></span> columns must follow. Each element of the matrix must be '<span class=\"tex-font-style-tt\">N</span>' or '<span class=\"tex-font-style-tt\">Y</span>'. If <span class=\"tex-span\"><i>G</i><sub class=\"lower-index\"><i>ij</i></sub></span> is '<span class=\"tex-font-style-tt\">Y</span>', then graph <span class=\"tex-span\"><i>G</i></span> has a edge connecting vertex <span class=\"tex-span\"><i>i</i></span> and vertex <span class=\"tex-span\"><i>j</i></span>. Consider the graph vertexes are numbered from 1 to <span class=\"tex-span\"><i>n</i></span>.</p><p>The graph must be undirected and simple: <span class=\"tex-span\"><i>G</i><sub class=\"lower-index\"><i>ii</i></sub></span> = '<span class=\"tex-font-style-tt\">N</span>' and <span class=\"tex-span\"><i>G</i><sub class=\"lower-index\"><i>ij</i></sub> = <i>G</i><sub class=\"lower-index\"><i>ji</i></sub></span> must hold. And there must be at least one path between vertex 1 and vertex 2. It's guaranteed that the answer exists. If there multiple correct answers, you can output any of them. </p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>2</pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>4<br/>NNYY<br/>NNYY<br/>YYNN<br/>YYNN</pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>9</pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>8<br/>NNYYYNNN<br/>NNNNNYYY<br/>YNNNNYYY<br/>YNNNNYYY<br/>YNNNNYYY<br/>NYYYYNNN<br/>NYYYYNNN<br/>NYYYYNNN</pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>1</pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>2<br/>NY<br/>YN</pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>In first example, there are 2 shortest paths: 1-3-2 and 1-4-2.</p><p>In second example, there are 9 shortest paths: 1-3-6-2, 1-3-7-2, 1-3-8-2, 1-4-6-2, 1-4-7-2, 1-4-8-2, 1-5-6-2, 1-5-7-2, 1-5-8-2.</p></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"7a1b2a42fbd499426470bce0a077f675\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - B - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"fe71135886e33994ae4d9b5e4703fc32ee0c7819\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - B - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/73366/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/73366/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/73366/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/73366/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/73366/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/73366/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/73366/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/73366/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/73366/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/73366/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/73366/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/73366/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/73366/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/73366/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/sidebar-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/a037fe51637846d9c7c725713cd840ea/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='7a1b2a42fbd499426470bce0a077f675'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/73366/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/73366/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fcontest%2F388%2Fproblem%2FB%3Flocale%3Den\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"current\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='7a1b2a42fbd499426470bce0a077f675'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:100%;\"><a style=\"color: black\" href=\"/contest/388\">Codeforces Round 228 (Div. 1)</a></th>\n </tr>\n <tr>\n <td class=\"left bottom\" colspan=\"1\"><span class=\"contest-state-phase\">Finished</span></td>\n </tr>\n </tbody>\n </table>\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Practice?\n <div class=\"top-links\">\n </div>\n </div>\n<div>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Want to solve the contest problems after the official contest ends? Just register for practice and you will be able to submit solutions.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"\" method=\"post\"><input type='hidden' name='csrf_token' value='7a1b2a42fbd499426470bce0a077f675'/>\r\n <input type=\"hidden\" name=\"action\" value=\"registerForPractice\"/>\r\n <input type=\"submit\" name=\"submit\" value=\"Register for practice\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div> \r\n</div>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox ContestVirtualFrame borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Virtual participation <i class=\"sidebar-caption-icon las la-angle-down\"></i>\r\n\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\" \"\r\n\r\n data-page-url=\"/data/sidebarFrames\"\r\n\r\n>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests.\n\nIf you've seen these problems, a virtual contest is not for you - solve these problems in the archive.\n\nIf you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.\n\nNever use someone else's code, read the tutorials or communicate with other person during a virtual contest.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"/contest/388/virtual\" method=\"get\">\r\n <input type=\"submit\" name=\"submit\" value=\"Start virtual contest\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div>\r\n</div>\r\n <script>\r\n $(function () {\r\n $(\".ContestVirtualFrame .sidebar-caption-icon\").click(function() {\r\n $(this).toggleClass(\"la-angle-down la-angle-right\");\r\n const $target = $(this).parent().next();\r\n $target.toggle();\r\n const dataPageUrl = $target.attr(\"data-page-url\");\r\n const collapsed = $(this).hasClass(\"la-angle-right\");\r\n const params = {\r\n action: \"setCollapsed\",\r\n sidebarFrameSimpleClassName: \"ContestVirtualFrame\",\r\n collapsed\r\n };\r\n $.each($target[0].attributes, function(i, a) {\r\n const name = a.name;\r\n if (name.startsWith(\"data-extra-key-\")) {\r\n const key = a.value;\r\n const keyIndex = parseInt(name.substring(\"data-extra-key-\".length));\r\n const value = $target.attr(\"data-extra-value-\" + keyIndex);\r\n params[key] = value;\r\n }\r\n });\r\n $.post(dataPageUrl, params, function (result) {\r\n if (result[\"success\"] !== \"true\") {\r\n Codeforces.showMessage(\"Failed to save collapsed state.\");\r\n }\r\n }, \"json\");\r\n return false;\r\n });\r\n })\r\n </script>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Problem tags\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Bitmasks\">\r\n bitmasks\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Constructive algorithms\">\r\n constructive algorithms\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Graphs\">\r\n graphs\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Implementation problems, programming technics, simulation\">\r\n implementation\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Mathematics including integration, differential equations, etc\">\r\n math\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Difficulty\">\r\n *1900\r\n</span>\r\n </div>\n <div style=\"clear:both;text-align:right;font-size:1.1rem;\">\r\n <span title=\"Please login into the Codeforces\" class=\"notice\">No tag edit access</span>\r\n </div>\r\n</div>\r\n </div>\n\r\n<form id=\"addTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='7a1b2a42fbd499426470bce0a077f675'/>\r\n <input name=\"action\" type=\"hidden\" value=\"addTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"6406\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<form id=\"removeTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='7a1b2a42fbd499426470bce0a077f675'/>\r\n <input name=\"action\" type=\"hidden\" value=\"removeTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"6406\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<script type=\"text/javascript\">\r\n $(\".tag-box img\").click(function () {\r\n var tagName = $(this).attr(\"value\");\r\n Codeforces.confirm(\"Are you sure you want to remove this tag?\", function () {\r\n $(\"#removeTagForm input[name=tagName]\").val(tagName);\r\n $(\"#removeTagForm\").submit();\r\n }, function () {\r\n }, \"Yes\", \"No\");\r\n });\r\n\r\n $(\"#addTagLink\").click(function () {\r\n $(this).hide();\r\n $(\"#addTagLabel\").show();\r\n return false;\r\n });\r\n\r\n $(\"#addTagSelect\").change(function () {\r\n var tagName = $(this).val();\r\n if (tagName === \"\") {\r\n $(\"#addTagLabel\").hide();\r\n $(\"#addTagLink\").show();\r\n } else {\r\n $(\"#addTagForm input[name=tagName]\").val(tagName);\r\n $(\"#addTagForm\").submit();\r\n }\r\n });\r\n</script>\r\n\r\n<style type=\"text/css\">\r\n#new-resource-form tr td {\r\npadding-top: 0.5em;\r\n}\r\n#new-resource-form input:not([type=\"submit\"]) {\r\nfont-size: 0.8em;\r\n}\r\n#new-resource-form select {\r\nfont-size: 0.8em;\r\n}\r\n.new-resource-error {\r\nfont-size: 0.8em;\r\n}\r\n.resource-locale {\r\ncolor: #666;\r\nfont-family: Consolas, \"Andale Mono WT\", \"Andale Mono\", \"Lucida Console\", \"Lucida Sans Typewriter\", \"DejaVu Sans Mono\", \"Bitstream Vera Sans Mono\", \"Liberation Mono\", \"Nimbus Mono L\", Monaco, \"Courier New\", Courier, monospace;\r\n}\r\n</style>\r\n<div class=\"roundbox sidebox sidebar-menu borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Contest materials\n<div class=\"top-links\">\n</div>\n</div>\n<ul>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/10605\" title=\"Codeforces Round #228\" target=\"_blank\">Codeforces Round #228</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"2187:2188\" resourceName=\"Announcement\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/10629\" title=\"Codeforces Round #228 — Editorial\" target=\"_blank\">Tutorial <span class=\"resource-locale\">(en)</span></a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"2192\" resourceName=\"Codeforces Round #228 — Editorial\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n</ul>\r\n</div></div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li class=\"current selectedLava\"><a\r\n href=\"/contest/388\">Problems</a></li>\r\n <li><a\r\n href=\"/contest/388/submit\">Submit Code</a></li>\r\n <li><a\r\n href=\"/contest/388/my\">My Submissions</a></li>\r\n <li><a\r\n href=\"/contest/388/status\">Status</a></li>\r\n <li><a\r\n href=\"/contest/388/hacks\">Hacks</a></li>\r\n <li><a\r\n href=\"/contest/388/room/1\">Room</a></li>\r\n <li><a\r\n href=\"/contest/388/standings\">Standings</a></li>\r\n <li><a\r\n href=\"/contest/388/customtest\">Custom Invocation</a></li>\r\n</ul>\r\n</div>\n\r\n <style>\r\n #facebox .content:has(.diff-popup) {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n }\r\n\r\n .testCaseMarker {\r\n position: absolute;\r\n font-weight: bold;\r\n font-size: 1rem;\r\n }\r\n\r\n .diff-popup {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n display: none;\r\n overflow: auto;\r\n }\r\n\r\n .input-output-copier {\r\n font-size: 1.2rem;\r\n float: right;\r\n color: #888 !important;\r\n cursor: pointer;\r\n border: 1px solid rgb(185, 185, 185);\r\n padding: 3px;\r\n margin: 1px;\r\n line-height: 1.1rem;\r\n text-transform: none;\r\n }\r\n\r\n .input-output-copier:hover {\r\n background-color: #def;\r\n }\r\n\r\n .test-explanation textarea {\r\n width: 100%;\r\n height: 1.5em;\r\n }\r\n\r\n .pending-submission-message {\r\n color: darkorange !important;\r\n }\r\n </style>\r\n <script>\r\n const OPENING_SPACE = String.fromCharCode(1001);\r\n const CLOSING_SPACE = String.fromCharCode(1002);\r\n\r\n const nodeToText = function (node, pre) {\r\n let result = [];\r\n\r\n if (node.tagName === \"SCRIPT\" || node.tagName === \"math\"\r\n || (node.classList && node.classList.contains(\"input-output-copier\")))\r\n return [];\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(OPENING_SPACE);\r\n }\r\n\r\n if (node.nodeType === Node.TEXT_NODE) {\r\n let s = node.textContent;\r\n if (!pre) {\r\n s = s.replace(/\\s+/g, \" \");\r\n }\r\n if (s.length > 0) {\r\n result.push(s);\r\n }\r\n }\r\n\r\n if (pre && node.tagName === \"BR\") {\r\n result.push(\"\\n\");\r\n }\r\n\r\n node.childNodes.forEach(function (child) {\r\n result.push(nodeToText(child, node.tagName === \"PRE\").join(\"\"));\r\n });\r\n\r\n if (node.tagName === \"DIV\"\r\n || node.tagName === \"P\"\r\n || node.tagName === \"PRE\"\r\n || node.tagName === \"UL\"\r\n || node.tagName === \"LI\"\r\n ) {\r\n result.push(\"\\n\");\r\n }\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(CLOSING_SPACE);\r\n }\r\n\r\n return result;\r\n }\r\n\r\n const isSpecial = function (c) {\r\n return c === ',' || c === '.' || c === ';' || c === ')' || c === ' ';\r\n }\r\n\r\n const convertStatementToText = function(statmentNode) {\r\n const text = nodeToText(statmentNode, false).join(\"\").replace(/ +/g, \" \").replace(/\\n\\n+/g, \"\\n\\n\");\r\n let result = [];\r\n for (let i = 0; i < text.length; i++) {\r\n const c = text.charAt(i);\r\n if (c === OPENING_SPACE) {\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"B\" data-uuid=\"ps_5bf23377fe15d5eac426e5307898c13d87c6d9e5\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">B. Fox and Minimal path</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Fox Ciel wants to write a task for a programming contest. The task is: "You are given a simple undirected graph with <span class=\"tex-span\"><i>n</i></span> vertexes. Each its edge has unit length. You should calculate the number of shortest paths between vertex 1 and vertex 2."</p><p>Same with some writers, she wants to make an example with some certain output: for example, her birthday or the number of her boyfriend. Can you help her to make a test case with answer equal exactly to <span class=\"tex-span\"><i>k</i></span>?</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains a single integer <span class=\"tex-span\"><i>k</i></span> (<span class=\"tex-span\">1 ≤ <i>k</i> ≤ 10<sup class=\"upper-index\">9</sup></span>).</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>You should output a graph <span class=\"tex-span\"><i>G</i></span> with <span class=\"tex-span\"><i>n</i></span> vertexes (<span class=\"tex-span\">2 ≤ <i>n</i> ≤ 1000</span>). There must be exactly <span class=\"tex-span\"><i>k</i></span> shortest paths between vertex 1 and vertex 2 of the graph.</p><p>The first line must contain an integer <span class=\"tex-span\"><i>n</i></span>. Then adjacency matrix <span class=\"tex-span\"><i>G</i></span> with <span class=\"tex-span\"><i>n</i></span> rows and <span class=\"tex-span\"><i>n</i></span> columns must follow. Each element of the matrix must be '<span class=\"tex-font-style-tt\">N</span>' or '<span class=\"tex-font-style-tt\">Y</span>'. If <span class=\"tex-span\"><i>G</i><sub class=\"lower-index\"><i>ij</i></sub></span> is '<span class=\"tex-font-style-tt\">Y</span>', then graph <span class=\"tex-span\"><i>G</i></span> has a edge connecting vertex <span class=\"tex-span\"><i>i</i></span> and vertex <span class=\"tex-span\"><i>j</i></span>. Consider the graph vertexes are numbered from 1 to <span class=\"tex-span\"><i>n</i></span>.</p><p>The graph must be undirected and simple: <span class=\"tex-span\"><i>G</i><sub class=\"lower-index\"><i>ii</i></sub></span> = '<span class=\"tex-font-style-tt\">N</span>' and <span class=\"tex-span\"><i>G</i><sub class=\"lower-index\"><i>ij</i></sub> = <i>G</i><sub class=\"lower-index\"><i>ji</i></sub></span> must hold. And there must be at least one path between vertex 1 and vertex 2. It's guaranteed that the answer exists. If there multiple correct answers, you can output any of them. </p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>2</pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>4<br />NNYY<br />NNYY<br />YYNN<br />YYNN</pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>9</pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>8<br />NNYYYNNN<br />NNNNNYYY<br />YNNNNYYY<br />YNNNNYYY<br />YNNNNYYY<br />NYYYYNNN<br />NYYYYNNN<br />NYYYYNNN</pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>1</pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>2<br />NY<br />YN</pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>In first example, there are 2 shortest paths: 1-3-2 and 1-4-2.</p><p>In second example, there are 9 shortest paths: 1-3-6-2, 1-3-7-2, 1-3-8-2, 1-4-6-2, 1-4-7-2, 1-4-8-2, 1-5-6-2, 1-5-7-2, 1-5-8-2.</p></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=B]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== statementText) {\r\n $problem.find(\".diff-notifier\").show();\r\n\r\n $problem.find(\".diff-notifier-close\").click(function() {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n $problem.find(\".diff-notifier\").hide();\r\n });\r\n\r\n $problem.find(\"a.view-changes\").click(function() {\r\n $.post(\"/data/diff\", {action: \"getDiff\", a: previousStatementText, b: statementText}, function (result) {\r\n if (result[\"success\"] === \"true\") {\r\n Codeforces.facebox(\".diff-popup\", \"//codeforces.org/s/73366\");\r\n $(\"#facebox .diff-popup\").html(result[\"diff\"]);\r\n }\r\n }, \"json\");\r\n });\r\n }\r\n } else {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n }\r\n });\r\n });\r\n </script>\r\n\r\n\r\n<script type=\"text/javascript\">\r\n $(document).ready(function () {\r\n window.changedTests = new Set();\r\n\r\n function endsWith(string, suffix) {\r\n return string.indexOf(suffix, string.length - suffix.length) !== -1;\r\n }\r\n\r\n const inputFileDiv = $(\"div.input-file\");\r\n const inputFile = inputFileDiv.text();\r\n const outputFileDiv = $(\"div.output-file\");\r\n const outputFile = outputFileDiv.text();\r\n\r\n\r\n if (!endsWith(inputFile, \"standard input\")\r\n && !endsWith(inputFile, \"standard input\")) {\r\n inputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n if (!endsWith(outputFile, \"standard output\")\r\n && !endsWith(outputFile, \"standard output\")) {\r\n outputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n const titleDiv = $(\"div.header div.title\");\r\n\r\n\r\n\r\n String.prototype.replaceAll = function (search, replace) {\r\n return this.split(search).join(replace);\r\n };\r\n\r\n $(\".sample-test .title\").each(function () {\r\n const preId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n const cpyId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n\r\n $(this).parent().find(\"pre\").attr(\"id\", preId);\r\n const $copy = $(\"<div title='Copy' data-clipboard-target='#\" + preId + \"' id='\" + cpyId + \"' class='input-output-copier'>Copy</div>\");\r\n $(this).append($copy);\r\n\r\n const clipboard = new Clipboard('#' + cpyId, {\r\n text: function (trigger) {\r\n const pre = document.querySelector('#' + preId);\r\n const lines = pre.querySelectorAll(\".test-example-line\");\r\n return Codeforces.filterClipboardText(pre.innerText, lines.length);\r\n }\r\n });\r\n\r\n const isInput = $(this).parent().hasClass(\"input\");\r\n\r\n clipboard.on('success', function (e) {\r\n if (isInput) {\r\n Codeforces.showMessage(\"The example input has been copied into the clipboard\");\r\n } else {\r\n Codeforces.showMessage(\"The example output has been copied into the clipboard\");\r\n }\r\n e.clearSelection();\r\n });\r\n });\r\n\r\n $(\".test-form-item input\").change(function () {\r\n addPendingSubmissionMessage($($(this).closest(\"form\")), \"You changed the answer, do not forget to submit it if you want to save the changes\");\r\n const index = $(this).closest(\".problemindexholder\").attr(\"problemindex\");\r\n let test = \"\";\r\n $(this).closest(\"form input\").each(function () {\r\n const test_ = $(this).attr(\"name\");\r\n if (test_ && test_.substring(0, 4) === \"test\") {\r\n test = test_;\r\n }\r\n });\r\n if (index.length > 0 && test.length > 0) {\r\n const indexTest = index + \"::\" + test;\r\n window.changedTests.add(indexTest);\r\n }\r\n });\r\n\r\n $(window).on('beforeunload', function () {\r\n if (window.changedTests.size > 0) {\r\n return 'Dialog text here';\r\n }\r\n });\r\n\r\n autosize($('.test-explanation textarea'));\r\n\r\n $(\".test-example-line\").hover(function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n let top = 1E20;\r\n let left = 1E20;\r\n let problem = $(this).closest(\".problemindexholder\");\r\n $(this).closest(\".input\").find(\".\" + clazz).css(\"background-color\", \"#FFFDE7\").each(function() {\r\n top = Math.min(top, $(this).offset().top);\r\n left = Math.min(left, $(this).offset().left);\r\n });\r\n let testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n if (testCaseMarker.length === 0) {\r\n const html = \"<div class=\\\"testCaseMarker testCaseMarker_\" + end + \" notice\\\"></div>\";\r\n problem.append($(html));\r\n testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n }\r\n if (testCaseMarker) {\r\n testCaseMarker.show()\r\n .offset({top, left: left - 20})\r\n .text(end);\r\n }\r\n }\r\n }\r\n });\r\n }, function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n $(\".\" + clazz).css(\"background-color\", \"\");\r\n $(this).closest(\".problemindexholder\").find(\".testCaseMarker_\" + end).hide();\r\n }\r\n }\r\n });\r\n });\r\n\r\n });\r\n</script>\r\n\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 05:38:31</span> (j3).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/73366/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/73366/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/73366/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/73366/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-73366.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'8122c4b41bcf0c42',t:'MTY5NjY0NjMxMS4xODMwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"},"long_tags":{"kind":"string","value":"[\"Bitmasks\", \"Constructive algorithms\", \"Graphs\", \"Implementation problems, programming technics, simulation\", \"Mathematics including integration, differential equations, etc\"]"},"short_tags":{"kind":"string","value":"[\"bitmasks\", \"constructive algorithms\", \"graphs\", \"implementation\", \"math\", \"*1900\"]"},"tutorial_link":{"kind":"string","value":"https://codeforces.com/blog/entry/10629"},"tutorial_page":{"kind":"string","value":"\r\n\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"74361418aed3add319d25ce966ceafdf\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"h1\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Codeforces Round #228 — Editorial - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n \n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Codeforces Round #228 — Editorial - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/81027/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/81027/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/81027/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/81027/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/81027/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/81027/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/81027/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/81027/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/81027/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/81027/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/81027/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/81027/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/81027/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/81027/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/573cedc6b04c15481941f418269f4057/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='74361418aed3add319d25ce966ceafdf'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/81027/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fblog%2Fentry%2F10629\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='74361418aed3add319d25ce966ceafdf'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Pay attention\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n <div style=\"text-align:center;border-bottom: 1px solid rgb(185, 185, 185);margin:0 -0.5em 0.5em -0.5em;padding: 0 1em 0.5em 1em;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 1, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:51:54</span><br/><a href=\"/contestRegistration/1876\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n <div style=\"text-align:center;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 2, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:51:54</span><br/><a href=\"/contestRegistration/1877\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='74361418aed3add319d25ce966ceafdf'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n </label>\r\n </div>\r\n <div style=\"padding: 0 1em 1em 1em;text-align:right;\">\r\n <input style=\"height:1.65em;padding:0 0.75em;\" type=\"submit\" value=\"Find\"/>\r\n </div>\r\n </form>\r\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".handleBox\").autocomplete(\"/data/handles\", {\r\n delay: 200,\r\n width: 200,\r\n selectFirst: false,\r\n matchContains: true,\r\n minChars: 3\r\n });\r\n $(\".handleForm\").attr(\"autocomplete\", \"off\").submit(function () {\r\n var link = \"/profile/userHandle\".replace(\r\n \"userHandle\", $(this).find(\".handleBox\").val()\r\n );\r\n window.location = link;\r\n return false;\r\n });\r\n });\n </script>\n\r\n\r\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Recent actions\n <div class=\"top-links\">\n </div>\n </div>\n <div class=\"recent-actions\">\r\n <ul>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/121073\">Meta Hacker Cup 2023 Round 1</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/.Danet\" title=\"Expert .Danet\" class=\"rated-user user-blue\">.Danet</a> →\r\n <a href=\"/blog/entry/121172\">[TLE on pretest1]</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\" class=\"rated-user user-red\">Pyqe</a> →\r\n <a href=\"/blog/entry/121025\">Codeforces Round #902 (Div. 1, Div. 2, based on COMPFEST 15 — Final Round)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pranshu_Pandya\" title=\"Specialist Pranshu_Pandya\" class=\"rated-user user-cyan\">Pranshu_Pandya</a> →\r\n <a href=\"/blog/entry/121171\">An Interesting Tree Problem</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/sszcdjr\" title=\"Master sszcdjr\" class=\"rated-user user-orange\">sszcdjr</a> →\r\n <a href=\"/blog/entry/119859\">Codeforces Round 896 (Div. 1, Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/119880\">It's Happening! Meta Hacker Cup 2023 Schedule</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/DaviddeGea1\" title=\"Expert DaviddeGea1\" class=\"rated-user user-blue\">DaviddeGea1</a> →\r\n <a href=\"/blog/entry/70917\">Number of ways of dividing an array into 2 parts such that sum of each part is > k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bekh\" title=\"Master Bekh\" class=\"rated-user user-orange\">Bekh</a> →\r\n <a href=\"/blog/entry/74245\">Questions and doubts regarding Aliens DP trick</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a> →\r\n <a href=\"/blog/entry/8192\">Codeforces Round #190 — Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/hocky\" title=\"Candidate Master hocky\" class=\"rated-user user-violet\">hocky</a> →\r\n <a href=\"/blog/entry/95323\">FBHC wuining uw Day? Incwease uw stacc size! (ㅅ´ ˘ `)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/liouzhou_101\" title=\"International Master liouzhou_101\" class=\"rated-user user-orange\">liouzhou_101</a> →\r\n <a href=\"/blog/entry/87598\">Editorial of Codeforces Round #700</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/yeon_gist\" title=\"Newbie yeon_gist\" class=\"rated-user user-gray\">yeon_gist</a> →\r\n <a href=\"/blog/entry/121170\">plusMinusPermutation computing error</a>\r\n <img alt=\"Text created or updated\" title=\"Text created or updated\" src=\"//codeforces.org/s/81027/images/icons/x-update-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/altforminuscontribution\" title=\"Newbie altforminuscontribution\" class=\"rated-user user-gray\">altforminuscontribution</a> →\r\n <a href=\"/blog/entry/121162\">My screen get unexpectedly big, what should I do</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/atcoder_official\" title=\"Unrated, atcoder_official\" class=\"rated-user user-black\">atcoder_official</a> →\r\n <a href=\"/blog/entry/121120\">We will hold UNIQUE VISION Programming Contest 2023 Autumn(AtCoder Beginner Contest 323)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/YouStill_DontKnowMeYet\" title=\"Candidate Master YouStill_DontKnowMeYet\" class=\"rated-user user-violet\">YouStill_DontKnowMeYet</a> →\r\n <a href=\"/blog/entry/117659\">[GYM] Al-Baath Collegiate Programming Contest 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/ankancool\" title=\"Expert ankancool\" class=\"rated-user user-blue\">ankancool</a> →\r\n <a href=\"/blog/entry/121136\">Invitation to AstroByte 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/GeZhiyuan\" title=\"Grandmaster GeZhiyuan\" class=\"rated-user user-red\">GeZhiyuan</a> →\r\n <a href=\"/blog/entry/120943\">Codeforces Round 901 (Div. 1, Div. 2) Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a> →\r\n <a href=\"/blog/entry/120772\">PSA: Increase your stack size before the Meta Hacker Cup, here's how</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/dino_merlin\" title=\"Expert dino_merlin\" class=\"rated-user user-blue\">dino_merlin</a> →\r\n <a href=\"/blog/entry/121145\">Intuitive approach for CEOI Kangaroo?</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/icecuber\" title=\"Grandmaster icecuber\" class=\"rated-user user-red\">icecuber</a> →\r\n <a href=\"/blog/entry/70018\">CSES DP section editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bn00b\" title=\"Newbie Bn00b\" class=\"rated-user user-gray\">Bn00b</a> →\r\n <a href=\"/blog/entry/98820\">[FEATURE REQUEST : ATCODER] TOPICS TAGS AND SORTING BY SOLVE COUNT</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a> →\r\n <a href=\"/blog/entry/121163\">AtCoder Regular Contest 166 Announcement</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/windva\" title=\"Grandmaster windva\" class=\"rated-user user-red\">windva</a> →\r\n <a href=\"/blog/entry/120644\">Codeforces Round 899 (Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Misa-Misa\" title=\"Expert Misa-Misa\" class=\"rated-user user-blue\">Misa-Misa</a> →\r\n <a href=\"/blog/entry/121157\">Someone please help me understand this.</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/shivam565\" title=\"Specialist shivam565\" class=\"rated-user user-cyan\">shivam565</a> →\r\n <a href=\"/blog/entry/108348\">Total number of subarrays with sum atmost k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n </ul>\r\n </div>\r\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/recent-actions\">Detailed →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n</div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li><a\r\n href=\"/profile/cgy4ever\">cgy4ever</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/cgy4ever\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/cgy4ever\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/cgy4ever\">Submissions</a></li>\r\n <li><a\r\n href=\"/groups/with/cgy4ever\">Groups</a></li>\r\n <li><a\r\n href=\"/contests/with/cgy4ever\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/cgy4ever\">Problemsetting</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/cgy4ever\" style=\"text-decoration:none;color:black !important;\">cgy4ever's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"10684\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/10629\"> <p>Codeforces Round #228 — Editorial</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a>,\r\n <span class=\"format-humantime\" title=\"Feb/03/2014 22:14\">10 years ago</span>,\r\n \r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p>You can find the editorial and my solutions here: <a href=\"https://github.com/cgy4ever/CF228\">https://github.com/cgy4ever/CF228</a></p><p><a href=\"/contest/389/problem/A\" title=\"Codeforces Round 228 (Div. 2)\">389A - Fox and Number Game</a></p><p>First we know that: in the optimal solution, all number will be equal: otherwise we can pick a and b (a < b) then do b = b — a, it will make the answer better.</p><p>Then we need an observation: after each operation, the GCD (Greatest common divisor) of all number will remain same. It can be proved by this lemma: if g is a divisor of all number of x[], then after the operation, g is still the divisor of these numbers, and vice versa.</p><p>So in the end, all number will become the GCD of x[].</p><p>Another solution that can pass is: While there exist x[i] > x[j], then do x[i] -= x[j]. We can select arbitrary i and j if there exist more than 1 choice.</p><p><a href=\"/contest/389/problem/B\" title=\"Codeforces Round 228 (Div. 2)\">389B - Fox and Cross</a></p><p>Let's define the first # of a shape is the cell contain # that have the lexicographical smallest coordinate. Then the first # of a cross is the top one.</p><p>Then let x be the first # of the given board. (If the board is empty, then we can draw it with zero crosses.) x must be covered by a cross, and x must be the first # of the cross. (You can try 4 other positions, it will cause a lexicographical smaller # in the board than x)</p><p>So we try to cover this x use one cross, if it leads some part of the cross covers a '.', then there will be no solution. If not, we just reduce the number of # in the board by 4, we can do this again and again.</p><p><a href=\"/contest/389/problem/C\" title=\"Codeforces Round 228 (Div. 2)\">389C - Fox and Box Accumulation</a> / <a href=\"/contest/388/problem/A\" title=\"Codeforces Round 228 (Div. 1)\">388A - Fox and Box Accumulation</a></p><p>We need some observation:</p> <ol> <li><p>There exists an optimal solution such that: in any pile, the box on the higher position will have a smaller strength.</p></li> <li><p>Let k be the minimal number of piles, then there exists an optimal solution such that: The height of all piles is n/k or n/k+1 (if n%k=0, then all of them have the height n/k).</p></li> </ol><p>We can prove them by exchange argument: from an optimal solution, swap the boxes in it to make above property holds, and we can ensure it will remain valid while swapping.</p><p>Then for a given k, we can check whether there exist a solution: the i-th (indexed from 0) smallest strength needs to be at least i/k.</p><p>So we can do binary search (or just enumerate, since n is only 100) on k.</p><p><a href=\"/contest/389/problem/D\" title=\"Codeforces Round 228 (Div. 2)\">389D - Fox and Minimal path</a> / <a href=\"/contest/388/problem/B\" title=\"Codeforces Round 228 (Div. 1)\">388B - Fox and Minimal path</a></p><p>First we need to know how to calculate the number of different shortest paths from vertex 1 to vertex 2: it can be done by dp: dp[1] = 1, dp[v] = sum{dp[t] | dist(1,t) = dist(1,v) — 1}, then dp[2] is our answer.</p><p>We need to do dp layer by layer. (first we consider vertexes have distance 1 to node 1, then vertexes have distance 2 to node 1 and so on.) So we can construct the graph layer by layer, and link edges to control the dp value of it.</p><p>My solution is construct the answer by binary express: If k is 19, then we need some vertexes in previous layer such that the dp value is 16, 2 and 1. So we just need a way to construct layer with dp value equals to 2^k.</p><p>In the first layer, it contains one node: 1, it has the dp value 1. In the next layer, we can construct 2 nodes, with dp value equals to 1. (We use [1 1] to denote it). And the next layer is [1 1 2], then [1 1 2 4], [1 1 2 4 8] and so on. So we need about 30 layers such that gets all 2^k where k < 30. It uses about 500 nodes.</p><p><a href=\"/contest/389/problem/E\" title=\"Codeforces Round 228 (Div. 2)\">389E - Fox and Card Game</a> / <a href=\"/contest/388/problem/C\" title=\"Codeforces Round 228 (Div. 1)\">388C - Fox and Card Game</a></p><p>First let's consider the case which all piles have even size. In this case, we can prove: in the optimal play, Ciel will gets all top most half cards of each pile, and Jiro gets the remain cards.</p><p>We can prove by these facts: Ciel have a strategy to ensure she can get this outcome and Jiro also have a strategy to ensure this outcome. (For Jiro this strategy is easy: just pick the card from pile that Ciel have just picked. For Ciel it's a little bit harder.)</p><p>Why we can conclude they are both the optimal strategy? Ciel just can't win more, because if she played with Jiro with above strategy, Jiro will get the bottom half of each pile.</p><p>Then we come back with cases that contain odd size piles. The result is: for odd size pile, Ciel will get the top (s-1)/2 cards and Jiro will get the bottom (s-1)/2 cards. Then what about the middle one? Let's denote S is all such middle cards. Then we define a reduced game: In each turn, they pick one card from S. The optimal play for this game is easy: Ciel gets the max one, and Jiro gets the 2nd largest one, and Ciel gets the 3rd largest one and so on.</p><p>We can prove Ciel have a strategy to get: all top half parts + cards she will get in the optimal play in the reduced game. And Jiro also have a strategy to get: all bottom half parts + cards he will get in the optimal play in the reduced game. And these strategy are optimal.</p><p><a href=\"/contest/388/problem/D\" title=\"Codeforces Round 228 (Div. 1)\">388D - Fox and Perfect Sets</a></p><p>A perfect set correspond to a linear space, so we can use base to represent it. We do the Gauss–Jordan elimination of vectors in that set, and can get an unique base. (Note that we need to to the all process of Gauss–Jordan elimination, including the elimination after it reached upper triangular)</p><p>And we can construct the bases bit by bit from higher bit to lower, for a bit:</p> <ol> <li><p>We can add a vector to the base such that the bit is the highest bit of that vector. And at this time, all other vector will have 0 in this bit.</p></li> <li><p>Otherwise we need to assign this bit of each vector already in the base. If now we have k vector, then we have 2^k choices.</p></li> </ol><p>And when we do this, we need to know what's the maximal vector in this space. It's not hard:</p> <ol> <li><p>If we add a vector, then in the maximal vector, this bit will be 1.</p></li> <li><p>Otherwise, if we don't have any vector in base yet, then this bit will be 0. Otherwise there will be 2^(k-1) choices results in this bit of maximal vector will be 0, and 2^(k-1) choices results in 1.</p></li> </ol><p>So we can solve this task by DP bit by bit.</p><p><a href=\"/contest/388/problem/E\" title=\"Codeforces Round 228 (Div. 1)\">388E - Fox and Meteor Shower</a></p><p>All tasks beside this are very easy to code. And this one focus on implementation.</p><p>We can represent the orbit of each meteor by a line in 3D space. (we use an axis to represent the time, and two axis to represent the position on the plane.)</p><p>Then the problem becomes: we have some lines in 3D space (they are not complete coincide), find a largest clique such that each pair of lines touch at some point.</p><p>We need this observation: If there are 3 lines in the optimal clique, and these 3 lines are not share a common point, then all line in this clique will on a plane.</p><p>By using this observation, we only need to consider 2 cases:</p> <ol> <li><p>All lines in the clique have a common point.</p></li> <li><p>All lines in the clique are on the same plane.</p></li> </ol><p>Both are easy tasks in theory, but it needs some coding.</p><p>There are two ways:</p> <ol> <li><p>Use integer anywhere. Note that the coordinates of intersection can be rational number, but can't be irrational, so we could do this. We can use some way to encode the plane, direction.</p></li> <li><p>Use floating number. To count same number of points, we can sort (x, y, z) by using the following compare function: if (abs(A.x — B.x) > eps){return A.x < B.x} otherwise { if(abs(A.y-B.y)>eps){return A.y < B.y} otherwise return A.z < B.z}.</p></li> </ol></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/388\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 228 (Div. 1)</a> </span>\r\n </div>\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/389\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 228 (Div. 2)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-21-10684\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"21\",\n blogEntryId: \"10629\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-10684\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+45</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-10684\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/cgy4ever\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/cgy4ever\">\n cgy4ever\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Feb/03/2014 22:14\">10 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/10629#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/10629#comments\">\n 44\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"10700\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (39)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159842\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/YaleZ\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/24526/avatar/5b17db1affad55a5.jpg'/> </a>\n <div><a href=\"/profile/YaleZ\" title=\"Expert YaleZ\" class=\"rated-user user-blue\">YaleZ</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2014 22:38\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159842\" href=\"?#comment-159842\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"159842\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"159842\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"24526\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159842\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thank for timely editorial. I think Markdown is better when publish something on Github. Isn't it?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159842 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159842 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159842\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159846\" commentParentId=\"159842\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/cgy4ever\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2014 22:43\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159846\" href=\"?#comment-159846\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159842\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159846\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"11\"\r\n data-commentUserId=\"62\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+11</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159846\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Yes, I'm working on it. :)</p><p>The website seems to be not stable at this time. So I post them in other sites to ensure all people can see it.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159846 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159846 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159846\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159857\" commentParentId=\"159846\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Nodir.Daminov\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/71439/avatar/d6d2016f6dfe5ecd.jpg'/> </a>\n <div><a href=\"/profile/Nodir.Daminov\" title=\"Candidate Master Nodir.Daminov\" class=\"rated-user user-violet\">Nodir.Daminov</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2014 22:58\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159857\" href=\"?#comment-159857\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159846\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159857\" class=\"CommentVoteFrame\"\r\n class=\"too-negative-comment-vote\"\r\n data-commentRating=\"-35\"\r\n data-commentUserId=\"71439\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-35</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159857\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Maaan is it so hard to COPY ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159857 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159857 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159857\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159874\" commentParentId=\"159857\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/cgy4ever\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2014 23:19\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159874\" href=\"?#comment-159874\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159857\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159874\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"12\"\r\n data-commentUserId=\"62\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+12</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159874\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Sorry for the delay.</p><p>When I was submitting my post that contains the editorial, it always returns "Codeforces is now unavailable." so I just can't post it.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159874 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159874 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159874\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159859\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/BishalG\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/60637/avatar/d21ddf49bbd1630c.jpg'/> </a>\n <div><a href=\"/profile/BishalG\" title=\"Expert BishalG\" class=\"rated-user user-blue\">BishalG</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2014 22:58\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159859\" href=\"?#comment-159859\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159859\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"60637\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159859\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Nice problemSets @<a class=\"rated-user user-orange\" href=\"/profile/cgy4ever\" title=\"International Master cgy4ever\">cgy4ever</a> , although I misunderstood the problem-B <a href=\"/contest/389/problem/B\" title=\"Codeforces Round 228 (Div. 2)\">389B - Fox and Cross</a> upto 1 hrs :( </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159859 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159859 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159859\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159867\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Mr.ink\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Mr.ink\" title=\"Expert Mr.ink\" class=\"rated-user user-blue\">Mr.ink</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2014 23:07\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159867\" href=\"?#comment-159867\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159867\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"128876\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159867\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>due to my slow internet speed i can not see your editorial on github because my country internet has problem with https! </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159867 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159867 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159867\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159881\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Mr.ink\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Mr.ink\" title=\"Expert Mr.ink\" class=\"rated-user user-blue\">Mr.ink</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2014 23:38\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159881\" href=\"?#comment-159881\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159881\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"128876\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159881\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>does anyone have a better solution for div2 C problem?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159881 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159881 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159881\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159883\" commentParentId=\"159881\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/t_thirupathi\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/146179/avatar/98c28348196ce4ca.jpg'/> </a>\n <div><a href=\"/profile/t_thirupathi\" title=\"Specialist t_thirupathi\" class=\"rated-user user-cyan\">t_thirupathi</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2014 23:42\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159883\" href=\"?#comment-159883\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159881\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159883\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"146179\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159883\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Have a look at mine <a href=\"/contest/389/submission/5878414\" title=\"Submission 5878414 by t_thirupathi\">5878414</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159883 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159883 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159883\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159909\" commentParentId=\"159883\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/9charles\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/119814/avatar/653156a3153bc2dd.jpg'/> </a>\n <div><a href=\"/profile/9charles\" title=\"Expert 9charles\" class=\"rated-user user-blue\">9charles</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 06:46\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159909\" href=\"?#comment-159909\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159883\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159909\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"119814\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159909\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can you explain it?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159909 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159909 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159909\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159907\" commentParentId=\"159881\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/k790alex\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/119882/avatar/4baeddca65b2b958.jpg'/> </a>\n <div><a href=\"/profile/k790alex\" title=\"Specialist k790alex\" class=\"rated-user user-cyan\">k790alex</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 06:28\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159907\" href=\"?#comment-159907\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159881\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159907\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"119882\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159907\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I don't know if this is a better way but I didt in the contest.</p><p>Start making a pile with the low strength and while possible, look for a box that can support at least 1 box, then at least 2 boxes, 3, etc, repeat it while you have boxes.</p><p>My solution: <a href=\"/contest/389/submission/5879464\" title=\"Submission 5879464 by k790alex\">5879464</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159907 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159907 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159907\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159914\" commentParentId=\"159907\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/YaleZ\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/24526/avatar/5b17db1affad55a5.jpg'/> </a>\n <div><a href=\"/profile/YaleZ\" title=\"Expert YaleZ\" class=\"rated-user user-blue\">YaleZ</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 07:38\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159914\" href=\"?#comment-159914\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159907\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159914\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"24526\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159914\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Greedy is also a nice solution.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159914 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159914 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159914\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159932\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/worfzyq\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/157364/avatar/8f104a361ed91be8.jpg'/> </a>\n <div><a href=\"/profile/worfzyq\" title=\"Expert worfzyq\" class=\"rated-user user-blue\">worfzyq</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 09:52\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159932\" href=\"?#comment-159932\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159932\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"157364\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159932\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>388C — Fox and Card Game This problem is good magic</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159932 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159932 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159932\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159935\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/orchidmajumder\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/63603/avatar/f8db3747466a7168.jpg'/> </a>\n <div><a href=\"/profile/orchidmajumder\" title=\"Specialist orchidmajumder\" class=\"rated-user user-cyan\">orchidmajumder</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 10:07\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159935\" href=\"?#comment-159935\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"159935\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"159935\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"7\"\r\n data-commentUserId=\"63603\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+7</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159935\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>hii everyone,in Div II E,I can't understand why the optimal play for JIRO is to take the bottom most card from the same pile from where CIEL is picking?should not it try to pick the maximum value among all bottom most card at it's every move??</p><p>Please someone explain why the strategy presented in the editorial is optimal.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159935 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159935 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159935\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159948\" commentParentId=\"159935\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Zzyzx\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/86049/avatar/c698ee674460e7eb.jpg'/> </a>\n <div><a href=\"/profile/Zzyzx\" title=\"Expert Zzyzx\" class=\"rated-user user-blue\">Zzyzx</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 13:07\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159948\" href=\"?#comment-159948\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159935\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159948\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"86049\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159948\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Ok, I'm afraid I do not have a rigorous proof for this. I'll just explain to you why I think it is right.</p><p>First of all, we need to understand that both Ciel and Jiro are smart. Now, whenever it is Ciel's turn, he will pick the "best pile" and try to take everything from that pile and then move on to the next "best pile". Jiro knows that his friend Ciel is smart, so he will try to stop him from taking everything. This can be done only if he picks from the same pile that Ciel does.</p><p>But your question is — what if there is a different pile whose bottom-most card is much better than the bottom-most card of the pile from which Ciel is picking right?</p><p>My answer to this is that, this situation will never arise. Because if there is such a pile, then Ciel will try to take that card in the first place and therefore, Ciel will be picking from the same pile that Jiro will want to pick from.</p><p>Am I making sense? Or is there a flaw in my argument?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159948 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159948 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159948\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159952\" commentParentId=\"159948\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/orchidmajumder\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/63603/avatar/f8db3747466a7168.jpg'/> </a>\n <div><a href=\"/profile/orchidmajumder\" title=\"Specialist orchidmajumder\" class=\"rated-user user-cyan\">orchidmajumder</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 13:32\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159952\" href=\"?#comment-159952\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159948\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159952\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"63603\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159952\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Yes I'm also thinking along the same line.Both are playing optimally and if Ciel is chosing any pile then jiro knows that this pile has better cards in the botttom half.So he won't choose ciel to take the advantage and vice versa.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159952 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159952 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159952\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159944\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hzyfr\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/hzyfr\" title=\"Expert hzyfr\" class=\"rated-user user-blue\">hzyfr</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 12:27\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159944\" href=\"?#comment-159944\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159944\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"129936\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159944\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I have a different idea on D div1 <a href=\"/contest/388/problem/D\" title=\"Codeforces Round 228 (Div. 1)\">388D - Fox and Perfect Sets</a> but I failed on getting some relations in one step.</p><p>Let <em>M</em> be the maximum element in set <em>S</em> . Then if <em>S</em> is a perfect set, its elements should have all bits equals <em>0</em> on positions in <em>M's</em> binary representation(otherwise there must exist another element bigger than <em>M</em>). So let <em>cnt</em> = (number of 1's in binary repersentation of <em>M</em>), then the number of perfect sets which has <em>M</em> as its greatest element is determined by <em>cnt</em> . Well, this is the step I can't come up with a solution(actually the target is to find the number of perfect sets which has <code>2^cnt-1</code> as its greatest element).</p><p>Then the last step is simple. We can apply something like doubling algorithm on the problem.</p><p>We are asked to find the number of perfect sets with all the elements not greater than <em>N</em> . Let's suppose <em>N+1</em> is a power of 2 then its easy to calculate how many numbers not greater than <em>N</em> has <em>cnt</em> = 1,2,...m where m is the length of <em>N</em> in binary representation. That's just simple combinatoric number <em>C(n,i) (1<=i<=n)</em> . And if we have done the previous step, it's easy to get the result.</p><p>Then think about common cases of <em>N</em> . Let's take the highest bit of N and since all above bits are determined, the number of 1's will just add a constant value. So calculate this part and subtract that highest bit of <em>N</em> and do the same thing on remaining value of <em>N</em> , until <em>N=0</em> . At that time we will get the correct answer. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159944 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159944 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159944\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159945\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/rexdf\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/23738/avatar/797fa665fbe1ca78.jpg'/> </a>\n <div><a href=\"/profile/rexdf\" title=\"Specialist rexdf\" class=\"rated-user user-cyan\">rexdf</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 12:36\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159945\" href=\"?#comment-159945\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159945\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"23738\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159945\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>dp[1] = 1, dp[v] = sum{dp[t] | dist(1,t) = dist(1,v) — 1}, then dp[2] is our answer. What's v means? what's '|' means? What's dp[v] means?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159945 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159945 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159945\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159949\" commentParentId=\"159945\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/sancho\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/85894/avatar/e31a4b24327c1000.jpg'/> </a>\n <div><a href=\"/profile/sancho\" title=\"Candidate Master sancho\" class=\"rated-user user-violet\">sancho</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 13:10\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159949\" href=\"?#comment-159949\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159945\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159949\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"85894\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159949\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>v — vertex, answer for which we are getting at this moment, | — means "such as", dp[v] — number of ways from 1 vertex to this one</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159949 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159949 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159949\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159947\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lol12\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/lol12\" title=\"Specialist lol12\" class=\"rated-user user-cyan\">lol12</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 13:04\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159947\" href=\"?#comment-159947\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159947\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"10\"\r\n data-commentUserId=\"152356\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+10</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159947\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can someone please explain solution of Div2-D. Thanx</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159947 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159947 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159947\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"160020\" commentParentId=\"159947\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/YaleZ\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/24526/avatar/5b17db1affad55a5.jpg'/> </a>\n <div><a href=\"/profile/YaleZ\" title=\"Expert YaleZ\" class=\"rated-user user-blue\">YaleZ</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/05/2014 07:07\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-160020\" href=\"?#comment-160020\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159947\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"160020\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"9\"\r\n data-commentUserId=\"24526\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+9</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-160020\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>You can think about binnary. Such as (13)10=(1101)2=((1+(2+0)*2)+1)*2+1</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-160020 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-160020 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-160020\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"469976\" commentParentId=\"159947\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/roll_no_1\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/631859/avatar/36d157f91f64fe7f.jpg'/> </a>\n <div><a href=\"/profile/roll_no_1\" title=\"Master roll_no_1\" class=\"rated-user user-orange\">roll_no_1</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Nov/09/2018 17:27\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-469976\" href=\"?#comment-469976\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159947\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"469976\" revisionCount=\"4\" revision=\"4\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">4</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"469976\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"631859\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-469976\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Here's my implementation of the editorialist's explanation of Div-2 D / Div-1 B: <a href=\"/contest/388/submission/45480077\" title=\"Submission 45480077 by roll_no_1\">45480077</a>. I implemented the layers as [1], [1, 1], [2, 1, 1], [4, 2, 1, 1] and so on.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-469976 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-469976 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-469976\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159967\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/BENYAM1N\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/84938/avatar/d2ae2657d8898e38.jpg'/> </a>\n <div><a href=\"/profile/BENYAM1N\" title=\"Master BENYAM1N\" class=\"rated-user user-orange\">BENYAM1N</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 15:51\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159967\" href=\"?#comment-159967\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159967\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"13\"\r\n data-commentUserId=\"84938\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+13</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159967\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Very good contest and nice editorial. Hope from now on I see more contests from you.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159967 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159967 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159967\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159984\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/kojak_\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/57722/avatar/38990eea59bc188e.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/kojak_\" title=\"Newbie kojak_\" class=\"rated-user user-gray\">kojak_</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 18:34\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159984\" href=\"?#comment-159984\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159984\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"57722\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159984\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Did anyone come up with a DP solution for Div.2 C/ Div.1 A?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159984 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159984 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159984\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"160012\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/IgorKoval\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/51322/avatar/afc854fff49f072a.jpg'/> </a>\n <div><a href=\"/profile/IgorKoval\" title=\"Candidate Master IgorKoval\" class=\"rated-user user-violet\">IgorKoval</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 23:17\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-160012\" href=\"?#comment-160012\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"160012\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"11\"\r\n data-commentUserId=\"51322\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+11</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-160012\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Объясните, пожалуйста, разбор задачи "388D — Fox and Perfect Sets" на пальцах. Как-нибудь без Гаусса и базисов. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-160012 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-160012 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-160012\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"160016\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Mr.ink\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Mr.ink\" title=\"Expert Mr.ink\" class=\"rated-user user-blue\">Mr.ink</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/05/2014 01:08\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-160016\" href=\"?#comment-160016\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"160016\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"128876\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-160016\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>fox and card games is a great problem.thanks!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-160016 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-160016 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-160016\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"160037\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/yaswanth\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/yaswanth\" title=\"Specialist yaswanth\" class=\"rated-user user-cyan\">yaswanth</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/05/2014 18:38\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-160037\" href=\"?#comment-160037\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"160037\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"9\"\r\n data-commentUserId=\"96196\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+9</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-160037\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can anyone explain div2 C question? I did not understand the editorial.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-160037 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-160037 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-160037\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"160063\" commentParentId=\"160037\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/YaleZ\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/24526/avatar/5b17db1affad55a5.jpg'/> </a>\n <div><a href=\"/profile/YaleZ\" title=\"Expert YaleZ\" class=\"rated-user user-blue\">YaleZ</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/06/2014 05:46\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-160063\" href=\"?#comment-160063\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-160037\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"160063\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"24526\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-160063\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>s[i]>=i/k -> k*s[i]>=i There are i boxes' strength smaller than i-th box. So we need to check if the boxes before i-th can be held.</p><p>(I don't know whether I have understood correctly...)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-160063 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-160063 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-160063\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"160053\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/yada\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/142663/avatar/49901b54d1c5f019.jpg'/> </a>\n <div><a href=\"/profile/yada\" title=\"Candidate Master yada\" class=\"rated-user user-violet\">yada</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/05/2014 23:24\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-160053\" href=\"?#comment-160053\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"160053\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"142663\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-160053\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Great Problem! I really enjoy it.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-160053 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-160053 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-160053\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"364019\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lnzva\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/305672/avatar/cf6c09a214141751.jpg'/> </a>\n <div><a href=\"/profile/lnzva\" title=\"Expert lnzva\" class=\"rated-user user-blue\">lnzva</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/02/2017 22:06\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-364019\" href=\"?#comment-364019\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"364019\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"364019\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"305672\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-364019\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In 388C, I'm having a hard time understanding why Jiro's optimal strategy would be to pick the pile Ciel just picked. Why not pick a pile which has a better bottom part than the one Ciel is picking? According to some comments, Ciel would then pick from the second pile-what if another pile has a much better top part? Could someone please help? I saw this problem first 6 months ago, and I had a hard time understanding why this greedy is correct; I saw this problem again today and am having trouble with it again, with no progress.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-364019 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-364019 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-364019\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"647866\" commentParentId=\"364019\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/_wzx27\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1458283/avatar/7d77b62012ae2398.jpg'/> </a>\n <div><a href=\"/profile/_wzx27\" title=\"Candidate Master _wzx27\" class=\"rated-user user-violet\">_wzx27</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/22/2020 18:33\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-647866\" href=\"?#comment-647866\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-364019\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"647866\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1458283\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-647866\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Let's consider such a two-piles situation:</p><p><em>111100</em></p><p><em>001111</em></p><p>is better for Ciel.</p><p>"1" means this card is picked by Ciel,while "0" by Jiro.</p><p>We know that better for Ciel means worse for Jiro.</p><p>So if</p><p><em>111100</em></p><p><em>001111</em></p><p>is better than</p><p><em>111000</em></p><p><em>000111</em></p><p>for Ciel.</p><p>Then when Ciel picked the <strong>first three cards</strong> from <strong>pile 1</strong>,Jiro can just pick the <strong>last three cards</strong> from <strong>pile 1</strong> and finally lead to the result:</p><p><em>111000</em></p><p><em>000111</em></p><p>which is not better for Ciel.</p><p>Generally, if the final result is not balance(half from top and half from bottom) while balance is better than such result for Jiro, Jiro has the ability to adjust it to be balance.So do Ciel.</p><p>Therefore,it reaches balance.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-647866 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-647866 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-647866\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"407776\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/madhur4127\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/568692/avatar/c7d62cc23c758819.jpg'/> </a>\n <div><a href=\"/profile/madhur4127\" title=\"Specialist madhur4127\" class=\"rated-user user-cyan\">madhur4127</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/15/2018 13:06\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-407776\" href=\"?#comment-407776\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"407776\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"568692\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-407776\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>@<a class=\"rated-user user-red\" href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\">cgy4ever</a>, github link shows 404 error(Page not found). Kindly fix it.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-407776 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-407776 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-407776\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"416354\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/introverted\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/657339/avatar/7a6edb1ecc1d3e09.jpg'/> </a>\n <div><a href=\"/profile/introverted\" title=\"Expert introverted\" class=\"rated-user user-blue\">introverted</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/23/2018 11:48\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-416354\" href=\"?#comment-416354\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"416354\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"657339\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-416354\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I solved the DIV1B problem with simple recursion and Divide and Conquer.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-416354 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-416354 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-416354\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"427890\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Nuu\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/652228/avatar/d59867d6477379dc.jpg'/> </a>\n <div><a href=\"/profile/Nuu\" title=\"Candidate Master Nuu\" class=\"rated-user user-violet\">Nuu</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/01/2018 22:33\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-427890\" href=\"?#comment-427890\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"427890\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"652228\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-427890\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can anyone give me some examples of the similar problems to DivC?? I think this problem is very nice for train brain xD</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-427890 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-427890 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-427890\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"629609\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/The_Alchemist\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1275181/avatar/662970aa05d3dfc5.jpg'/> </a>\n <div><a href=\"/profile/The_Alchemist\" title=\"Expert The_Alchemist\" class=\"rated-user user-blue\">The_Alchemist</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/25/2020 21:47\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-629609\" href=\"?#comment-629609\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"629609\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1275181\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-629609\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I know I am very late but can someone pls explain to me div 2C/div1A. Thanks in advance... </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-629609 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-629609 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-629609\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"641010\" commentParentId=\"629609\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/kstheking\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1160931/avatar/e144fc7b0fdb90b1.jpg'/> </a>\n <div><a href=\"/profile/kstheking\" title=\"Pupil kstheking\" class=\"rated-user user-green\">kstheking</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/13/2020 14:47\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-641010\" href=\"?#comment-641010\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-629609\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"641010\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1160931\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-641010\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p><a href=\"https://codeforces.com/contest/388/submission/83605110\">https://codeforces.com/contest/388/submission/83605110</a> Here you go, if you don't get it feel free to ask</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-641010 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-641010 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-641010\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"644488\" commentParentId=\"641010\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/tanisha_\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/tanisha_\" title=\"Newbie tanisha_\" class=\"rated-user user-gray\">tanisha_</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/18/2020 15:26\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-644488\" href=\"?#comment-644488\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-641010\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"644488\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1500127\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-644488\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>is this any algorithm</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-644488 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-644488 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-644488\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"647627\" commentParentId=\"644488\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/kstheking\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1160931/avatar/e144fc7b0fdb90b1.jpg'/> </a>\n <div><a href=\"/profile/kstheking\" title=\"Pupil kstheking\" class=\"rated-user user-green\">kstheking</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/22/2020 08:40\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-647627\" href=\"?#comment-647627\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-644488\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"647627\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"647627\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1160931\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-647627\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Well you can call it a greedy algorithm, when we try to apply greedy by placing the heaviest block in bottom, a little problem occurs because of blocks of same strength for example in case of 10 2 2 1 1 0 0<br />If you try to apply greedy by choosing the strongest block<br />10 2 2 1<br />1 0<br />0<br />= 3 heaps<br />Which is wrong answer as sometimes we lose opportunity to create lesser heaps, as in this case if we use the second 2 to make another heap we can do better<br />10 2 1 0<br />2 1 0<br />= 2 heaps<br />So I apply greedy in the reverse direction by picking the smallest strength brick and placing below it the next smallest brick, this way the optimal number of heaps will be formed as in above example<br />choose 0, then you need >= 1, choose 1, then you need >= 2, choose 2, then you need >= 3 choose 10<br />repeat until you have chosen all the bricks<br />If you don't get anything, feel free to ask :) </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-647627 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-647627 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-647627\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"702677\" commentParentId=\"647627\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/breddreamer\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/853067/avatar/240684624b57996.jpg'/> </a>\n <div><a href=\"/profile/breddreamer\" title=\"Newbie breddreamer\" class=\"rated-user user-gray\">breddreamer</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/27/2020 13:01\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-702677\" href=\"?#comment-702677\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-647627\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"702677\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"853067\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-702677\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks, It helped me to understand your solution idea. And finally, I solved this one.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-702677 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-702677 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-702677\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"649225\" commentParentId=\"641010\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/The_Alchemist\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1275181/avatar/662970aa05d3dfc5.jpg'/> </a>\n <div><a href=\"/profile/The_Alchemist\" title=\"Expert The_Alchemist\" class=\"rated-user user-blue\">The_Alchemist</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/24/2020 12:04\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-649225\" href=\"?#comment-649225\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-641010\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"649225\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1275181\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-649225\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>thank you.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-649225 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-649225 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-649225\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n <br/>\r\n\r\n<div id=\"editBox-10700\" style=\"width:50em;display:none;\">\r\n <div class=\"previewBody\" style=\"border: 1px solid #d4d4d4; margin-bottom: 0.5em; padding: 0.25em; display:none;\"> </div>\r\n <div style=\"width: 1px\"> </div>\r\n <div class=\"commentLocale\" style=\"position: relative; top: 0.5em;left:4px;display: none;\">\r\n <input type=\"radio\" name=\"locale\" value=\"en\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In English</span>\r\n <input style=\"margin-left:1em\" type=\"radio\" name=\"locale\" value=\"ru\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In Russian</span>\r\n </div>\r\n <textarea data-drafts-id=\"CommentReplyFrame\" class=\"wysiwyg\" name=\"editContent\" rows=\"20\" style=\"width:99%;\"></textarea>\r\n <div class=\"error error__content\"></div>\r\n <div style=\"text-align:center;\">\r\n <input type=\"button\" name=\"preview\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Preview\"/>\r\n <input type=\"button\" name=\"save\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Save\"/>\r\n </div>\r\n</div>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n\r\nvar firstPreview10700 = true;\r\nvar lastPreviewContent10700 = '';\r\n\r\nif (!window.moveCommentRevision) {\r\n moveCommentRevision = function(e, dir) {\r\n var p = e.parent();\r\n var revisionCount = parseInt(p.attr(\"revisionCount\"));\r\n var revision = parseInt(p.attr(\"revision\"));\r\n var next = revision + dir;\r\n var commentId = p.attr(\"commentId\");\r\n if (next >= 1 && next <= revisionCount) {\r\n $.post(\r\n \"/data/comment-data\",\r\n {action: \"revision\", commentId: commentId, revision: next},\r\n function(json) {\r\n if (json.success == \"true\") {\r\n var parentDiv = e;\r\n\r\n while (parentDiv !== null && (parentDiv[0].nodeName.toLowerCase() !== \"td\" || !parentDiv.hasClass(\"right\"))) {\r\n parentDiv = parentDiv.parent();\r\n }\r\n\r\n if (parentDiv === null) {\r\n return;\r\n }\r\n\r\n parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\").html(json.content);\r\n Codeforces.setupSpoilers(parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\"));\r\n p.attr(\"revision\", next);\r\n p.find(\"span.revision\").text(next);\r\n if (next == 1) {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"visible\");\r\n }\r\n if (next == revisionCount) {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"visible\");\r\n }\r\n\r\n window.updateTypography();\r\n MathJax.Hub.Typeset();\r\n } else {\r\n alert(e.error);\r\n }\r\n },\r\n \"json\"\r\n );\r\n }\r\n };\r\n}\r\n\r\n$(\"div[commentableId=10700] a.leftRevision\").click(function () {\r\n window.moveCommentRevision($(this), -1);\r\n return false;\r\n});\r\n\r\n$(\"div[commentableId=10700] a.rightRevision\").click(function () {\r\n window.moveCommentRevision($(this), +1);\r\n return false;\r\n});\r\n\r\n\r\n\r\n });\n </script>\n\r\n\r\n <script src=\"//codeforces.org/s/81027/js/swfobject-2.2.min.js\" type=\"text/javascript\"></script>\n <script src=\"//codeforces.org/s/81027/js/ftaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n if (window.evercookie) {\n var ec = new evercookie({\n history: false,\n silverlight: false,\n baseurl: '',\n asseturi: '/assets',\n phpuri: '/2fdcd78',\n pngPath: '/eps',\n etagPath: '/ees',\n cachePath: '/ecs'\n });\n\n var randomNumber = function () {\n return Math.random().toString(36).substr(2);\n };\n\n var randomToken = function () {\n return (randomNumber() + randomNumber()).substring(0, 18);\n };\n\n window._ftaa = \"\";\n\n ec.get(\"70a7c28f3de\", function (value) {\n window._ftaa = value;\n if (!window._ftaa) {\n window._ftaa = randomToken();\n ec.set(\"70a7c28f3de\", window._ftaa);\n }\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n } else {\n window._ftaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\n <script src=\"//codeforces.org/s/81027/js/bfaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n var fpCallback = function() {\n Fingerprint2.get({}, function(components) {\n window._bfaa = Fingerprint2.x64hash128(components.map(function (pair) { return pair.value }).join(), 31);\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n };\n if (typeof Fingerprint2 !== 'undefined') {\n if (window.requestIdleCallback) {\n requestIdleCallback(fpCallback)\n } else {\n setTimeout(fpCallback, 500)\n }\n } else {\n window._bfaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"a.new-root-comment\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n\r\n $(\".comment-table .reply a\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".vote-for-comment\").mouseover(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").mouseout(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").click(function () {\r\n var vote = $(this);\r\n var commentId = $(this).parent().attr(\"commentid\");\r\n var commentRating = $(this).parent().attr(\"data-commentRating\");\r\n var direction = $(this).attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n $.post(\"/data/comment/vote\", {commentId: commentId, _tta: Codeforces.tta(), vote: direction, commentRating: commentRating}, function(data) {\r\n if (direction != 0 && !ownComment && data[\"success\"] == \"true\") {\r\n vote.parent().find(\".vote-for-comment\").attr(\"voteDirection\", 0);\r\n if (direction == 1)\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n else {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.closest(\".CommentVoteFrame\").find(\".ComplaintFrame\").css(\"display\", \"inline-block\");\r\n }\r\n vote.find(\"img\").attr(\"popacity\", \"1.0\");\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n vote.parent().find(\".commentRating\").html(data[\"commentRating\"]);\r\n }\r\n Codeforces.showMessage(data[\"message\"]);\r\n }, \"json\");\r\n return false;\r\n });\r\n\r\n $(\".negative-comment-vote\").closest(\".comment-table\").addClass(\"comment-bad\");\r\n\r\n $(\".troll-comment-vote\").closest(\".comment\").css(\"display\", \"none\");\r\n\r\n $(\".too-negative-comment-vote\").closest(\".comment-table\").each(function () {\r\n var e = $(this);\r\n e.addClass(\"comment-too-bad\");\r\n var commentId = e.attr(\"commentId\");\r\n $(\"<div class='bad-comment-replacement ttypography'>The comment is hidden because of too negative feedback, click <a href=# class=show-bad-comment-link>here</a> to view it</div>\").appendTo(\r\n e.find(\".right\")\r\n );\r\n e.find(\".comment-content\").hide();\r\n e.find(\".show-bad-comment-link\").click(function () {\r\n e.find(\".comment-content\").show();\r\n e.find(\".bad-comment-replacement\").hide();\r\n return false;\r\n });\r\n });\r\n });\n </script>\n </div>\r\n\r\n <style type=\"text/css\">\r\n .new-comments-box {\r\n padding: 0.5em;\r\n width: 22px;\r\n font-size: 1.3rem;\r\n font-weight: bold !important;\r\n\r\n position: fixed;\r\n top: 40%;\r\n right: 0;\r\n opacity: 0.2;\r\n color: white;\r\n text-align: center;\r\n\r\n border: 1px solid #222;\r\n background-color: #888 !important;\r\n border-radius: 3px;\r\n -moz-border-radius: 3px;\r\n -webkit-border-radius: 3px;\r\n }\r\n\r\n .new-comments-box:hover {\r\n opacity: 1;\r\n }\r\n\r\n .new-comments-box .dir:hover {\r\n background: #3B5998 !important;\r\n cursor: pointer;\r\n }\r\n </style>\r\n\r\n <div class=\"new-comments-box\" data-position=\"outside\" data-index=\"-1\" style=\"display: none;\">\r\n <div class=\"up dir\" title=\"Ctrl+Up\">↑<hr/>\r\n </div>\r\n <div class=\"info\" title=\"New comments\"></div>\r\n <div class=\"down dir\" title=\"Ctrl+Down\">\r\n <hr/>↓\r\n </div>\r\n </div>\r\n\r\n <script>\r\n $(\".show-archived-checkbox\").change(function () {\r\n const checked = $(this).is(\":checked\");\r\n $.post(\"/data/comment-data\", {action: \"setShowArchived\", checked}, function (json) {\r\n if (json[\"success\"] !== \"true\") {\r\n alert(json[\"error\"]);\r\n } else {\r\n if (checked) {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are now displayed\")\r\n } else {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are no longer displayed\")\r\n }\r\n }\r\n });\r\n return false;\r\n });\r\n\r\n function gotoComment(direction) {\r\n var box = $(\".new-comments-box\");\r\n var index = parseInt(box.attr(\"data-index\"));\r\n if (index == -1)\r\n index = 0;\r\n else\r\n index = Math.max(0, Math.min(parseInt(box.find(\".info\").text()) - 1, index + direction));\r\n box.attr(\"data-index\", index);\r\n var comment = $($(\".comment .highlight-blue[commentId]\").get(index));\r\n $('html, body').animate({\r\n 'scrollTop': Math.max(0, comment.offset().top - ($(window).height() - comment.height()) / 2)\r\n });\r\n return false;\r\n }\r\n\r\n $(\".new-comments-box .down\").click(function () {\r\n return gotoComment(1);\r\n });\r\n\r\n $(\".new-comments-box .up\").click(function () {\r\n return gotoComment(-1);\r\n });\r\n\r\n $(document).keydown(function (e) {\r\n var code = (e.keyCode ? e.keyCode : e.which);\r\n if (e.ctrlKey) {\r\n if (code == 38 || code == 40) {\r\n gotoComment(code - 39);\r\n }\r\n }\r\n });\r\n\r\n var newCommentCount = $(\".comment .highlight-blue[commentId]\").length;\r\n if (newCommentCount > 0) {\r\n $(\".new-comments-box .info\").text(newCommentCount);\r\n $(\".new-comments-box\").show();\r\n }\r\n\r\n $('table.comment-table').mouseenter(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").addClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n\r\n $('table.comment-table').mouseleave(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").removeClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n </script>\r\n\r\n\r\n\r\n <script>\r\n function adjustTopicComplainFrames() {\r\n let topicIds = [];\r\n\r\n $(\".has-topic-id\").each(function () {\r\n const $this = $(this);\r\n const topicId = $this.attr(\"topicId\");\r\n if (topicId) {\r\n topicIds.push(topicId);\r\n }\r\n });\r\n\r\n $.post(\"/data/topics\", {\r\n action: \"findComplainableTopicIds\",\r\n topicIds: topicIds.join(\",\")\r\n }, function (json) {\r\n if (json[\"success\"] === \"true\") {\r\n for (const topicId of json[\"complainableTopicIds\"].split(\",\")) {\r\n $(\".has-topic-id[topicId=\" + topicId + \"]\").each(function () {\r\n $(this).find(\".meta .ComplaintFrame\").css(\"display\", \"inline-block\");\r\n });\r\n }\r\n }\r\n }, \"json\");\r\n }\r\n\r\n $(function () {\r\n adjustTopicComplainFrames();\r\n })\r\n </script>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-10684\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 10684, _tta: Codeforces.tta(), topicRevisionId: 36670, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-10684\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 10684, _tta: Codeforces.tta(), topicRevisionId: 36670, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n </div>\r\n </div>\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 22:13:07</span> (h1).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/81027/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/81027/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/81027/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/81027/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-81027.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'812875a2ab4016f4',t:'MTY5NjcwNTk4Ny4yMjQwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"}}},{"rowIdx":1960,"cells":{"problem_id":{"kind":"string","value":"388C"},"contest":{"kind":"string","value":"388"},"problem":{"kind":"string","value":"C"},"lang":{"kind":"string","value":"en"},"problem_title":{"kind":"string","value":"C. Fox and Card Game"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">C. Fox and Card Game</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Fox Ciel is playing a card game with her friend Fox Jiro. There are <span class=\"tex-span\"><i>n</i></span> piles of cards on the table. And there is a positive integer on each card.</p><p>The players take turns and Ciel takes the first turn. In Ciel's turn she takes a card from the top of any non-empty pile, and in Jiro's turn he takes a card from the bottom of any non-empty pile. Each player wants to maximize the total sum of the cards he took. The game ends when all piles become empty.</p><p>Suppose Ciel and Jiro play optimally, what is the score of the game?</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contain an integer <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">1 ≤ <i>n</i> ≤ 100</span>). Each of the next <span class=\"tex-span\"><i>n</i></span> lines contains a description of the pile: the first integer in the line is <span class=\"tex-span\"><i>s</i><sub class=\"lower-index\"><i>i</i></sub></span> (<span class=\"tex-span\">1 ≤ <i>s</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 100</span>) — the number of cards in the <span class=\"tex-span\"><i>i</i></span>-th pile; then follow <span class=\"tex-span\"><i>s</i><sub class=\"lower-index\"><i>i</i></sub></span> positive integers <span class=\"tex-span\"><i>c</i><sub class=\"lower-index\">1</sub></span>, <span class=\"tex-span\"><i>c</i><sub class=\"lower-index\">2</sub></span>, ..., <span class=\"tex-span\"><i>c</i><sub class=\"lower-index\"><i>k</i></sub></span>, ..., <span class=\"tex-span\"><i>c</i><sub class=\"lower-index\"><i>s</i><sub class=\"lower-index\"><i>i</i></sub></sub></span> (<span class=\"tex-span\">1 ≤ <i>c</i><sub class=\"lower-index\"><i>k</i></sub> ≤ 1000</span>) — the sequence of the numbers on the cards listed from top of the current pile to bottom of the pile.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print two integers: the sum of Ciel's cards and the sum of Jiro's cards if they play optimally.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>2<br/>1 100<br/>2 1 10<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>101 10<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>1<br/>9 2 8 6 5 9 4 7 1 3<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>30 15<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3<br/>3 1 3 2<br/>3 5 4 6<br/>2 8 7<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>18 18<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3<br/>3 1000 1000 1000<br/>6 1000 1000 1000 1000 1000 1000<br/>5 1000 1000 1000 1000 1000<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>7000 7000<br/></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>In the first example, Ciel will take the cards with number 100 and 1, Jiro will take the card with number 10.</p><p>In the second example, Ciel will take cards with numbers 2, 8, 6, 5, 9 and Jiro will take cards with numbers 4, 7, 1, 3.</p></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"0aa443fefa8cd3702a6588509a481862\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - C - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"fe71135886e33994ae4d9b5e4703fc32ee0c7819\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - C - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/73366/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/73366/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/73366/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/73366/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/73366/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/73366/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/73366/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/73366/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/73366/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/73366/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/73366/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/73366/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/73366/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/73366/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/sidebar-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/a037fe51637846d9c7c725713cd840ea/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='0aa443fefa8cd3702a6588509a481862'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/73366/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/73366/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fcontest%2F388%2Fproblem%2FC%3Flocale%3Den\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"current\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='0aa443fefa8cd3702a6588509a481862'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:100%;\"><a style=\"color: black\" href=\"/contest/388\">Codeforces Round 228 (Div. 1)</a></th>\n </tr>\n <tr>\n <td class=\"left bottom\" colspan=\"1\"><span class=\"contest-state-phase\">Finished</span></td>\n </tr>\n </tbody>\n </table>\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Practice?\n <div class=\"top-links\">\n </div>\n </div>\n<div>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Want to solve the contest problems after the official contest ends? Just register for practice and you will be able to submit solutions.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"\" method=\"post\"><input type='hidden' name='csrf_token' value='0aa443fefa8cd3702a6588509a481862'/>\r\n <input type=\"hidden\" name=\"action\" value=\"registerForPractice\"/>\r\n <input type=\"submit\" name=\"submit\" value=\"Register for practice\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div> \r\n</div>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox ContestVirtualFrame borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Virtual participation <i class=\"sidebar-caption-icon las la-angle-down\"></i>\r\n\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\" \"\r\n\r\n data-page-url=\"/data/sidebarFrames\"\r\n\r\n>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests.\n\nIf you've seen these problems, a virtual contest is not for you - solve these problems in the archive.\n\nIf you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.\n\nNever use someone else's code, read the tutorials or communicate with other person during a virtual contest.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"/contest/388/virtual\" method=\"get\">\r\n <input type=\"submit\" name=\"submit\" value=\"Start virtual contest\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div>\r\n</div>\r\n <script>\r\n $(function () {\r\n $(\".ContestVirtualFrame .sidebar-caption-icon\").click(function() {\r\n $(this).toggleClass(\"la-angle-down la-angle-right\");\r\n const $target = $(this).parent().next();\r\n $target.toggle();\r\n const dataPageUrl = $target.attr(\"data-page-url\");\r\n const collapsed = $(this).hasClass(\"la-angle-right\");\r\n const params = {\r\n action: \"setCollapsed\",\r\n sidebarFrameSimpleClassName: \"ContestVirtualFrame\",\r\n collapsed\r\n };\r\n $.each($target[0].attributes, function(i, a) {\r\n const name = a.name;\r\n if (name.startsWith(\"data-extra-key-\")) {\r\n const key = a.value;\r\n const keyIndex = parseInt(name.substring(\"data-extra-key-\".length));\r\n const value = $target.attr(\"data-extra-value-\" + keyIndex);\r\n params[key] = value;\r\n }\r\n });\r\n $.post(dataPageUrl, params, function (result) {\r\n if (result[\"success\"] !== \"true\") {\r\n Codeforces.showMessage(\"Failed to save collapsed state.\");\r\n }\r\n }, \"json\");\r\n return false;\r\n });\r\n })\r\n </script>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Problem tags\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Games, Sprague–Grundy theorem\">\r\n games\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Greedy algorithms\">\r\n greedy\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Sortings, orderings\">\r\n sortings\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Difficulty\">\r\n *2000\r\n</span>\r\n </div>\n <div style=\"clear:both;text-align:right;font-size:1.1rem;\">\r\n <span title=\"Please login into the Codeforces\" class=\"notice\">No tag edit access</span>\r\n </div>\r\n</div>\r\n </div>\n\r\n<form id=\"addTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='0aa443fefa8cd3702a6588509a481862'/>\r\n <input name=\"action\" type=\"hidden\" value=\"addTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"6407\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<form id=\"removeTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='0aa443fefa8cd3702a6588509a481862'/>\r\n <input name=\"action\" type=\"hidden\" value=\"removeTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"6407\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<script type=\"text/javascript\">\r\n $(\".tag-box img\").click(function () {\r\n var tagName = $(this).attr(\"value\");\r\n Codeforces.confirm(\"Are you sure you want to remove this tag?\", function () {\r\n $(\"#removeTagForm input[name=tagName]\").val(tagName);\r\n $(\"#removeTagForm\").submit();\r\n }, function () {\r\n }, \"Yes\", \"No\");\r\n });\r\n\r\n $(\"#addTagLink\").click(function () {\r\n $(this).hide();\r\n $(\"#addTagLabel\").show();\r\n return false;\r\n });\r\n\r\n $(\"#addTagSelect\").change(function () {\r\n var tagName = $(this).val();\r\n if (tagName === \"\") {\r\n $(\"#addTagLabel\").hide();\r\n $(\"#addTagLink\").show();\r\n } else {\r\n $(\"#addTagForm input[name=tagName]\").val(tagName);\r\n $(\"#addTagForm\").submit();\r\n }\r\n });\r\n</script>\r\n\r\n<style type=\"text/css\">\r\n#new-resource-form tr td {\r\npadding-top: 0.5em;\r\n}\r\n#new-resource-form input:not([type=\"submit\"]) {\r\nfont-size: 0.8em;\r\n}\r\n#new-resource-form select {\r\nfont-size: 0.8em;\r\n}\r\n.new-resource-error {\r\nfont-size: 0.8em;\r\n}\r\n.resource-locale {\r\ncolor: #666;\r\nfont-family: Consolas, \"Andale Mono WT\", \"Andale Mono\", \"Lucida Console\", \"Lucida Sans Typewriter\", \"DejaVu Sans Mono\", \"Bitstream Vera Sans Mono\", \"Liberation Mono\", \"Nimbus Mono L\", Monaco, \"Courier New\", Courier, monospace;\r\n}\r\n</style>\r\n<div class=\"roundbox sidebox sidebar-menu borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Contest materials\n<div class=\"top-links\">\n</div>\n</div>\n<ul>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/10605\" title=\"Codeforces Round #228\" target=\"_blank\">Codeforces Round #228</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"2187:2188\" resourceName=\"Announcement\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/10629\" title=\"Codeforces Round #228 — Editorial\" target=\"_blank\">Tutorial <span class=\"resource-locale\">(en)</span></a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"2192\" resourceName=\"Codeforces Round #228 — Editorial\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n</ul>\r\n</div></div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li class=\"current selectedLava\"><a\r\n href=\"/contest/388\">Problems</a></li>\r\n <li><a\r\n href=\"/contest/388/submit\">Submit Code</a></li>\r\n <li><a\r\n href=\"/contest/388/my\">My Submissions</a></li>\r\n <li><a\r\n href=\"/contest/388/status\">Status</a></li>\r\n <li><a\r\n href=\"/contest/388/hacks\">Hacks</a></li>\r\n <li><a\r\n href=\"/contest/388/room/1\">Room</a></li>\r\n <li><a\r\n href=\"/contest/388/standings\">Standings</a></li>\r\n <li><a\r\n href=\"/contest/388/customtest\">Custom Invocation</a></li>\r\n</ul>\r\n</div>\n\r\n <style>\r\n #facebox .content:has(.diff-popup) {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n }\r\n\r\n .testCaseMarker {\r\n position: absolute;\r\n font-weight: bold;\r\n font-size: 1rem;\r\n }\r\n\r\n .diff-popup {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n display: none;\r\n overflow: auto;\r\n }\r\n\r\n .input-output-copier {\r\n font-size: 1.2rem;\r\n float: right;\r\n color: #888 !important;\r\n cursor: pointer;\r\n border: 1px solid rgb(185, 185, 185);\r\n padding: 3px;\r\n margin: 1px;\r\n line-height: 1.1rem;\r\n text-transform: none;\r\n }\r\n\r\n .input-output-copier:hover {\r\n background-color: #def;\r\n }\r\n\r\n .test-explanation textarea {\r\n width: 100%;\r\n height: 1.5em;\r\n }\r\n\r\n .pending-submission-message {\r\n color: darkorange !important;\r\n }\r\n </style>\r\n <script>\r\n const OPENING_SPACE = String.fromCharCode(1001);\r\n const CLOSING_SPACE = String.fromCharCode(1002);\r\n\r\n const nodeToText = function (node, pre) {\r\n let result = [];\r\n\r\n if (node.tagName === \"SCRIPT\" || node.tagName === \"math\"\r\n || (node.classList && node.classList.contains(\"input-output-copier\")))\r\n return [];\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(OPENING_SPACE);\r\n }\r\n\r\n if (node.nodeType === Node.TEXT_NODE) {\r\n let s = node.textContent;\r\n if (!pre) {\r\n s = s.replace(/\\s+/g, \" \");\r\n }\r\n if (s.length > 0) {\r\n result.push(s);\r\n }\r\n }\r\n\r\n if (pre && node.tagName === \"BR\") {\r\n result.push(\"\\n\");\r\n }\r\n\r\n node.childNodes.forEach(function (child) {\r\n result.push(nodeToText(child, node.tagName === \"PRE\").join(\"\"));\r\n });\r\n\r\n if (node.tagName === \"DIV\"\r\n || node.tagName === \"P\"\r\n || node.tagName === \"PRE\"\r\n || node.tagName === \"UL\"\r\n || node.tagName === \"LI\"\r\n ) {\r\n result.push(\"\\n\");\r\n }\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(CLOSING_SPACE);\r\n }\r\n\r\n return result;\r\n }\r\n\r\n const isSpecial = function (c) {\r\n return c === ',' || c === '.' || c === ';' || c === ')' || c === ' ';\r\n }\r\n\r\n const convertStatementToText = function(statmentNode) {\r\n const text = nodeToText(statmentNode, false).join(\"\").replace(/ +/g, \" \").replace(/\\n\\n+/g, \"\\n\\n\");\r\n let result = [];\r\n for (let i = 0; i < text.length; i++) {\r\n const c = text.charAt(i);\r\n if (c === OPENING_SPACE) {\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"C\" data-uuid=\"ps_b851b1b1ab29a6a21db7782ad3a9bf0c9cb31c2a\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">C. Fox and Card Game</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Fox Ciel is playing a card game with her friend Fox Jiro. There are <span class=\"tex-span\"><i>n</i></span> piles of cards on the table. And there is a positive integer on each card.</p><p>The players take turns and Ciel takes the first turn. In Ciel's turn she takes a card from the top of any non-empty pile, and in Jiro's turn he takes a card from the bottom of any non-empty pile. Each player wants to maximize the total sum of the cards he took. The game ends when all piles become empty.</p><p>Suppose Ciel and Jiro play optimally, what is the score of the game?</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contain an integer <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">1 ≤ <i>n</i> ≤ 100</span>). Each of the next <span class=\"tex-span\"><i>n</i></span> lines contains a description of the pile: the first integer in the line is <span class=\"tex-span\"><i>s</i><sub class=\"lower-index\"><i>i</i></sub></span> (<span class=\"tex-span\">1 ≤ <i>s</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 100</span>) — the number of cards in the <span class=\"tex-span\"><i>i</i></span>-th pile; then follow <span class=\"tex-span\"><i>s</i><sub class=\"lower-index\"><i>i</i></sub></span> positive integers <span class=\"tex-span\"><i>c</i><sub class=\"lower-index\">1</sub></span>, <span class=\"tex-span\"><i>c</i><sub class=\"lower-index\">2</sub></span>, ..., <span class=\"tex-span\"><i>c</i><sub class=\"lower-index\"><i>k</i></sub></span>, ..., <span class=\"tex-span\"><i>c</i><sub class=\"lower-index\"><i>s</i><sub class=\"lower-index\"><i>i</i></sub></sub></span> (<span class=\"tex-span\">1 ≤ <i>c</i><sub class=\"lower-index\"><i>k</i></sub> ≤ 1000</span>) — the sequence of the numbers on the cards listed from top of the current pile to bottom of the pile.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print two integers: the sum of Ciel's cards and the sum of Jiro's cards if they play optimally.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>2<br />1 100<br />2 1 10<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>101 10<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>1<br />9 2 8 6 5 9 4 7 1 3<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>30 15<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3<br />3 1 3 2<br />3 5 4 6<br />2 8 7<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>18 18<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3<br />3 1000 1000 1000<br />6 1000 1000 1000 1000 1000 1000<br />5 1000 1000 1000 1000 1000<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>7000 7000<br /></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>In the first example, Ciel will take the cards with number 100 and 1, Jiro will take the card with number 10.</p><p>In the second example, Ciel will take cards with numbers 2, 8, 6, 5, 9 and Jiro will take cards with numbers 4, 7, 1, 3.</p></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=C]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== statementText) {\r\n $problem.find(\".diff-notifier\").show();\r\n\r\n $problem.find(\".diff-notifier-close\").click(function() {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n $problem.find(\".diff-notifier\").hide();\r\n });\r\n\r\n $problem.find(\"a.view-changes\").click(function() {\r\n $.post(\"/data/diff\", {action: \"getDiff\", a: previousStatementText, b: statementText}, function (result) {\r\n if (result[\"success\"] === \"true\") {\r\n Codeforces.facebox(\".diff-popup\", \"//codeforces.org/s/73366\");\r\n $(\"#facebox .diff-popup\").html(result[\"diff\"]);\r\n }\r\n }, \"json\");\r\n });\r\n }\r\n } else {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n }\r\n });\r\n });\r\n </script>\r\n\r\n\r\n<script type=\"text/javascript\">\r\n $(document).ready(function () {\r\n window.changedTests = new Set();\r\n\r\n function endsWith(string, suffix) {\r\n return string.indexOf(suffix, string.length - suffix.length) !== -1;\r\n }\r\n\r\n const inputFileDiv = $(\"div.input-file\");\r\n const inputFile = inputFileDiv.text();\r\n const outputFileDiv = $(\"div.output-file\");\r\n const outputFile = outputFileDiv.text();\r\n\r\n\r\n if (!endsWith(inputFile, \"standard input\")\r\n && !endsWith(inputFile, \"standard input\")) {\r\n inputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n if (!endsWith(outputFile, \"standard output\")\r\n && !endsWith(outputFile, \"standard output\")) {\r\n outputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n const titleDiv = $(\"div.header div.title\");\r\n\r\n\r\n\r\n String.prototype.replaceAll = function (search, replace) {\r\n return this.split(search).join(replace);\r\n };\r\n\r\n $(\".sample-test .title\").each(function () {\r\n const preId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n const cpyId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n\r\n $(this).parent().find(\"pre\").attr(\"id\", preId);\r\n const $copy = $(\"<div title='Copy' data-clipboard-target='#\" + preId + \"' id='\" + cpyId + \"' class='input-output-copier'>Copy</div>\");\r\n $(this).append($copy);\r\n\r\n const clipboard = new Clipboard('#' + cpyId, {\r\n text: function (trigger) {\r\n const pre = document.querySelector('#' + preId);\r\n const lines = pre.querySelectorAll(\".test-example-line\");\r\n return Codeforces.filterClipboardText(pre.innerText, lines.length);\r\n }\r\n });\r\n\r\n const isInput = $(this).parent().hasClass(\"input\");\r\n\r\n clipboard.on('success', function (e) {\r\n if (isInput) {\r\n Codeforces.showMessage(\"The example input has been copied into the clipboard\");\r\n } else {\r\n Codeforces.showMessage(\"The example output has been copied into the clipboard\");\r\n }\r\n e.clearSelection();\r\n });\r\n });\r\n\r\n $(\".test-form-item input\").change(function () {\r\n addPendingSubmissionMessage($($(this).closest(\"form\")), \"You changed the answer, do not forget to submit it if you want to save the changes\");\r\n const index = $(this).closest(\".problemindexholder\").attr(\"problemindex\");\r\n let test = \"\";\r\n $(this).closest(\"form input\").each(function () {\r\n const test_ = $(this).attr(\"name\");\r\n if (test_ && test_.substring(0, 4) === \"test\") {\r\n test = test_;\r\n }\r\n });\r\n if (index.length > 0 && test.length > 0) {\r\n const indexTest = index + \"::\" + test;\r\n window.changedTests.add(indexTest);\r\n }\r\n });\r\n\r\n $(window).on('beforeunload', function () {\r\n if (window.changedTests.size > 0) {\r\n return 'Dialog text here';\r\n }\r\n });\r\n\r\n autosize($('.test-explanation textarea'));\r\n\r\n $(\".test-example-line\").hover(function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n let top = 1E20;\r\n let left = 1E20;\r\n let problem = $(this).closest(\".problemindexholder\");\r\n $(this).closest(\".input\").find(\".\" + clazz).css(\"background-color\", \"#FFFDE7\").each(function() {\r\n top = Math.min(top, $(this).offset().top);\r\n left = Math.min(left, $(this).offset().left);\r\n });\r\n let testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n if (testCaseMarker.length === 0) {\r\n const html = \"<div class=\\\"testCaseMarker testCaseMarker_\" + end + \" notice\\\"></div>\";\r\n problem.append($(html));\r\n testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n }\r\n if (testCaseMarker) {\r\n testCaseMarker.show()\r\n .offset({top, left: left - 20})\r\n .text(end);\r\n }\r\n }\r\n }\r\n });\r\n }, function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n $(\".\" + clazz).css(\"background-color\", \"\");\r\n $(this).closest(\".problemindexholder\").find(\".testCaseMarker_\" + end).hide();\r\n }\r\n }\r\n });\r\n });\r\n\r\n });\r\n</script>\r\n\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 05:38:32</span> (j3).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/73366/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/73366/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/73366/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/73366/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-73366.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'8122c4bc887603dd',t:'MTY5NjY0NjMxMi40ODAwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"},"long_tags":{"kind":"string","value":"[\"Games, Sprague\\u2013Grundy theorem\", \"Greedy algorithms\", \"Sortings, orderings\"]"},"short_tags":{"kind":"string","value":"[\"games\", \"greedy\", \"sortings\", \"*2000\"]"},"tutorial_link":{"kind":"string","value":"https://codeforces.com/blog/entry/10629"},"tutorial_page":{"kind":"string","value":"\r\n\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"74361418aed3add319d25ce966ceafdf\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"h1\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Codeforces Round #228 — Editorial - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n \n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Codeforces Round #228 — Editorial - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/81027/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/81027/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/81027/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/81027/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/81027/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/81027/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/81027/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/81027/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/81027/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/81027/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/81027/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/81027/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/81027/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/81027/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/573cedc6b04c15481941f418269f4057/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='74361418aed3add319d25ce966ceafdf'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/81027/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fblog%2Fentry%2F10629\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='74361418aed3add319d25ce966ceafdf'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Pay attention\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n <div style=\"text-align:center;border-bottom: 1px solid rgb(185, 185, 185);margin:0 -0.5em 0.5em -0.5em;padding: 0 1em 0.5em 1em;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 1, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:51:54</span><br/><a href=\"/contestRegistration/1876\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n <div style=\"text-align:center;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 2, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:51:54</span><br/><a href=\"/contestRegistration/1877\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='74361418aed3add319d25ce966ceafdf'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n </label>\r\n </div>\r\n <div style=\"padding: 0 1em 1em 1em;text-align:right;\">\r\n <input style=\"height:1.65em;padding:0 0.75em;\" type=\"submit\" value=\"Find\"/>\r\n </div>\r\n </form>\r\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".handleBox\").autocomplete(\"/data/handles\", {\r\n delay: 200,\r\n width: 200,\r\n selectFirst: false,\r\n matchContains: true,\r\n minChars: 3\r\n });\r\n $(\".handleForm\").attr(\"autocomplete\", \"off\").submit(function () {\r\n var link = \"/profile/userHandle\".replace(\r\n \"userHandle\", $(this).find(\".handleBox\").val()\r\n );\r\n window.location = link;\r\n return false;\r\n });\r\n });\n </script>\n\r\n\r\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Recent actions\n <div class=\"top-links\">\n </div>\n </div>\n <div class=\"recent-actions\">\r\n <ul>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/121073\">Meta Hacker Cup 2023 Round 1</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/.Danet\" title=\"Expert .Danet\" class=\"rated-user user-blue\">.Danet</a> →\r\n <a href=\"/blog/entry/121172\">[TLE on pretest1]</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\" class=\"rated-user user-red\">Pyqe</a> →\r\n <a href=\"/blog/entry/121025\">Codeforces Round #902 (Div. 1, Div. 2, based on COMPFEST 15 — Final Round)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pranshu_Pandya\" title=\"Specialist Pranshu_Pandya\" class=\"rated-user user-cyan\">Pranshu_Pandya</a> →\r\n <a href=\"/blog/entry/121171\">An Interesting Tree Problem</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/sszcdjr\" title=\"Master sszcdjr\" class=\"rated-user user-orange\">sszcdjr</a> →\r\n <a href=\"/blog/entry/119859\">Codeforces Round 896 (Div. 1, Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/119880\">It's Happening! Meta Hacker Cup 2023 Schedule</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/DaviddeGea1\" title=\"Expert DaviddeGea1\" class=\"rated-user user-blue\">DaviddeGea1</a> →\r\n <a href=\"/blog/entry/70917\">Number of ways of dividing an array into 2 parts such that sum of each part is > k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bekh\" title=\"Master Bekh\" class=\"rated-user user-orange\">Bekh</a> →\r\n <a href=\"/blog/entry/74245\">Questions and doubts regarding Aliens DP trick</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a> →\r\n <a href=\"/blog/entry/8192\">Codeforces Round #190 — Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/hocky\" title=\"Candidate Master hocky\" class=\"rated-user user-violet\">hocky</a> →\r\n <a href=\"/blog/entry/95323\">FBHC wuining uw Day? Incwease uw stacc size! (ㅅ´ ˘ `)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/liouzhou_101\" title=\"International Master liouzhou_101\" class=\"rated-user user-orange\">liouzhou_101</a> →\r\n <a href=\"/blog/entry/87598\">Editorial of Codeforces Round #700</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/yeon_gist\" title=\"Newbie yeon_gist\" class=\"rated-user user-gray\">yeon_gist</a> →\r\n <a href=\"/blog/entry/121170\">plusMinusPermutation computing error</a>\r\n <img alt=\"Text created or updated\" title=\"Text created or updated\" src=\"//codeforces.org/s/81027/images/icons/x-update-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/altforminuscontribution\" title=\"Newbie altforminuscontribution\" class=\"rated-user user-gray\">altforminuscontribution</a> →\r\n <a href=\"/blog/entry/121162\">My screen get unexpectedly big, what should I do</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/atcoder_official\" title=\"Unrated, atcoder_official\" class=\"rated-user user-black\">atcoder_official</a> →\r\n <a href=\"/blog/entry/121120\">We will hold UNIQUE VISION Programming Contest 2023 Autumn(AtCoder Beginner Contest 323)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/YouStill_DontKnowMeYet\" title=\"Candidate Master YouStill_DontKnowMeYet\" class=\"rated-user user-violet\">YouStill_DontKnowMeYet</a> →\r\n <a href=\"/blog/entry/117659\">[GYM] Al-Baath Collegiate Programming Contest 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/ankancool\" title=\"Expert ankancool\" class=\"rated-user user-blue\">ankancool</a> →\r\n <a href=\"/blog/entry/121136\">Invitation to AstroByte 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/GeZhiyuan\" title=\"Grandmaster GeZhiyuan\" class=\"rated-user user-red\">GeZhiyuan</a> →\r\n <a href=\"/blog/entry/120943\">Codeforces Round 901 (Div. 1, Div. 2) Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a> →\r\n <a href=\"/blog/entry/120772\">PSA: Increase your stack size before the Meta Hacker Cup, here's how</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/dino_merlin\" title=\"Expert dino_merlin\" class=\"rated-user user-blue\">dino_merlin</a> →\r\n <a href=\"/blog/entry/121145\">Intuitive approach for CEOI Kangaroo?</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/icecuber\" title=\"Grandmaster icecuber\" class=\"rated-user user-red\">icecuber</a> →\r\n <a href=\"/blog/entry/70018\">CSES DP section editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bn00b\" title=\"Newbie Bn00b\" class=\"rated-user user-gray\">Bn00b</a> →\r\n <a href=\"/blog/entry/98820\">[FEATURE REQUEST : ATCODER] TOPICS TAGS AND SORTING BY SOLVE COUNT</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a> →\r\n <a href=\"/blog/entry/121163\">AtCoder Regular Contest 166 Announcement</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/windva\" title=\"Grandmaster windva\" class=\"rated-user user-red\">windva</a> →\r\n <a href=\"/blog/entry/120644\">Codeforces Round 899 (Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Misa-Misa\" title=\"Expert Misa-Misa\" class=\"rated-user user-blue\">Misa-Misa</a> →\r\n <a href=\"/blog/entry/121157\">Someone please help me understand this.</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/shivam565\" title=\"Specialist shivam565\" class=\"rated-user user-cyan\">shivam565</a> →\r\n <a href=\"/blog/entry/108348\">Total number of subarrays with sum atmost k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n </ul>\r\n </div>\r\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/recent-actions\">Detailed →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n</div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li><a\r\n href=\"/profile/cgy4ever\">cgy4ever</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/cgy4ever\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/cgy4ever\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/cgy4ever\">Submissions</a></li>\r\n <li><a\r\n href=\"/groups/with/cgy4ever\">Groups</a></li>\r\n <li><a\r\n href=\"/contests/with/cgy4ever\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/cgy4ever\">Problemsetting</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/cgy4ever\" style=\"text-decoration:none;color:black !important;\">cgy4ever's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"10684\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/10629\"> <p>Codeforces Round #228 — Editorial</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a>,\r\n <span class=\"format-humantime\" title=\"Feb/03/2014 22:14\">10 years ago</span>,\r\n \r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p>You can find the editorial and my solutions here: <a href=\"https://github.com/cgy4ever/CF228\">https://github.com/cgy4ever/CF228</a></p><p><a href=\"/contest/389/problem/A\" title=\"Codeforces Round 228 (Div. 2)\">389A - Fox and Number Game</a></p><p>First we know that: in the optimal solution, all number will be equal: otherwise we can pick a and b (a < b) then do b = b — a, it will make the answer better.</p><p>Then we need an observation: after each operation, the GCD (Greatest common divisor) of all number will remain same. It can be proved by this lemma: if g is a divisor of all number of x[], then after the operation, g is still the divisor of these numbers, and vice versa.</p><p>So in the end, all number will become the GCD of x[].</p><p>Another solution that can pass is: While there exist x[i] > x[j], then do x[i] -= x[j]. We can select arbitrary i and j if there exist more than 1 choice.</p><p><a href=\"/contest/389/problem/B\" title=\"Codeforces Round 228 (Div. 2)\">389B - Fox and Cross</a></p><p>Let's define the first # of a shape is the cell contain # that have the lexicographical smallest coordinate. Then the first # of a cross is the top one.</p><p>Then let x be the first # of the given board. (If the board is empty, then we can draw it with zero crosses.) x must be covered by a cross, and x must be the first # of the cross. (You can try 4 other positions, it will cause a lexicographical smaller # in the board than x)</p><p>So we try to cover this x use one cross, if it leads some part of the cross covers a '.', then there will be no solution. If not, we just reduce the number of # in the board by 4, we can do this again and again.</p><p><a href=\"/contest/389/problem/C\" title=\"Codeforces Round 228 (Div. 2)\">389C - Fox and Box Accumulation</a> / <a href=\"/contest/388/problem/A\" title=\"Codeforces Round 228 (Div. 1)\">388A - Fox and Box Accumulation</a></p><p>We need some observation:</p> <ol> <li><p>There exists an optimal solution such that: in any pile, the box on the higher position will have a smaller strength.</p></li> <li><p>Let k be the minimal number of piles, then there exists an optimal solution such that: The height of all piles is n/k or n/k+1 (if n%k=0, then all of them have the height n/k).</p></li> </ol><p>We can prove them by exchange argument: from an optimal solution, swap the boxes in it to make above property holds, and we can ensure it will remain valid while swapping.</p><p>Then for a given k, we can check whether there exist a solution: the i-th (indexed from 0) smallest strength needs to be at least i/k.</p><p>So we can do binary search (or just enumerate, since n is only 100) on k.</p><p><a href=\"/contest/389/problem/D\" title=\"Codeforces Round 228 (Div. 2)\">389D - Fox and Minimal path</a> / <a href=\"/contest/388/problem/B\" title=\"Codeforces Round 228 (Div. 1)\">388B - Fox and Minimal path</a></p><p>First we need to know how to calculate the number of different shortest paths from vertex 1 to vertex 2: it can be done by dp: dp[1] = 1, dp[v] = sum{dp[t] | dist(1,t) = dist(1,v) — 1}, then dp[2] is our answer.</p><p>We need to do dp layer by layer. (first we consider vertexes have distance 1 to node 1, then vertexes have distance 2 to node 1 and so on.) So we can construct the graph layer by layer, and link edges to control the dp value of it.</p><p>My solution is construct the answer by binary express: If k is 19, then we need some vertexes in previous layer such that the dp value is 16, 2 and 1. So we just need a way to construct layer with dp value equals to 2^k.</p><p>In the first layer, it contains one node: 1, it has the dp value 1. In the next layer, we can construct 2 nodes, with dp value equals to 1. (We use [1 1] to denote it). And the next layer is [1 1 2], then [1 1 2 4], [1 1 2 4 8] and so on. So we need about 30 layers such that gets all 2^k where k < 30. It uses about 500 nodes.</p><p><a href=\"/contest/389/problem/E\" title=\"Codeforces Round 228 (Div. 2)\">389E - Fox and Card Game</a> / <a href=\"/contest/388/problem/C\" title=\"Codeforces Round 228 (Div. 1)\">388C - Fox and Card Game</a></p><p>First let's consider the case which all piles have even size. In this case, we can prove: in the optimal play, Ciel will gets all top most half cards of each pile, and Jiro gets the remain cards.</p><p>We can prove by these facts: Ciel have a strategy to ensure she can get this outcome and Jiro also have a strategy to ensure this outcome. (For Jiro this strategy is easy: just pick the card from pile that Ciel have just picked. For Ciel it's a little bit harder.)</p><p>Why we can conclude they are both the optimal strategy? Ciel just can't win more, because if she played with Jiro with above strategy, Jiro will get the bottom half of each pile.</p><p>Then we come back with cases that contain odd size piles. The result is: for odd size pile, Ciel will get the top (s-1)/2 cards and Jiro will get the bottom (s-1)/2 cards. Then what about the middle one? Let's denote S is all such middle cards. Then we define a reduced game: In each turn, they pick one card from S. The optimal play for this game is easy: Ciel gets the max one, and Jiro gets the 2nd largest one, and Ciel gets the 3rd largest one and so on.</p><p>We can prove Ciel have a strategy to get: all top half parts + cards she will get in the optimal play in the reduced game. And Jiro also have a strategy to get: all bottom half parts + cards he will get in the optimal play in the reduced game. And these strategy are optimal.</p><p><a href=\"/contest/388/problem/D\" title=\"Codeforces Round 228 (Div. 1)\">388D - Fox and Perfect Sets</a></p><p>A perfect set correspond to a linear space, so we can use base to represent it. We do the Gauss–Jordan elimination of vectors in that set, and can get an unique base. (Note that we need to to the all process of Gauss–Jordan elimination, including the elimination after it reached upper triangular)</p><p>And we can construct the bases bit by bit from higher bit to lower, for a bit:</p> <ol> <li><p>We can add a vector to the base such that the bit is the highest bit of that vector. And at this time, all other vector will have 0 in this bit.</p></li> <li><p>Otherwise we need to assign this bit of each vector already in the base. If now we have k vector, then we have 2^k choices.</p></li> </ol><p>And when we do this, we need to know what's the maximal vector in this space. It's not hard:</p> <ol> <li><p>If we add a vector, then in the maximal vector, this bit will be 1.</p></li> <li><p>Otherwise, if we don't have any vector in base yet, then this bit will be 0. Otherwise there will be 2^(k-1) choices results in this bit of maximal vector will be 0, and 2^(k-1) choices results in 1.</p></li> </ol><p>So we can solve this task by DP bit by bit.</p><p><a href=\"/contest/388/problem/E\" title=\"Codeforces Round 228 (Div. 1)\">388E - Fox and Meteor Shower</a></p><p>All tasks beside this are very easy to code. And this one focus on implementation.</p><p>We can represent the orbit of each meteor by a line in 3D space. (we use an axis to represent the time, and two axis to represent the position on the plane.)</p><p>Then the problem becomes: we have some lines in 3D space (they are not complete coincide), find a largest clique such that each pair of lines touch at some point.</p><p>We need this observation: If there are 3 lines in the optimal clique, and these 3 lines are not share a common point, then all line in this clique will on a plane.</p><p>By using this observation, we only need to consider 2 cases:</p> <ol> <li><p>All lines in the clique have a common point.</p></li> <li><p>All lines in the clique are on the same plane.</p></li> </ol><p>Both are easy tasks in theory, but it needs some coding.</p><p>There are two ways:</p> <ol> <li><p>Use integer anywhere. Note that the coordinates of intersection can be rational number, but can't be irrational, so we could do this. We can use some way to encode the plane, direction.</p></li> <li><p>Use floating number. To count same number of points, we can sort (x, y, z) by using the following compare function: if (abs(A.x — B.x) > eps){return A.x < B.x} otherwise { if(abs(A.y-B.y)>eps){return A.y < B.y} otherwise return A.z < B.z}.</p></li> </ol></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/388\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 228 (Div. 1)</a> </span>\r\n </div>\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/389\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 228 (Div. 2)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-21-10684\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"21\",\n blogEntryId: \"10629\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-10684\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+45</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-10684\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/cgy4ever\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/cgy4ever\">\n cgy4ever\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Feb/03/2014 22:14\">10 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/10629#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/10629#comments\">\n 44\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"10700\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (39)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159842\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/YaleZ\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/24526/avatar/5b17db1affad55a5.jpg'/> </a>\n <div><a href=\"/profile/YaleZ\" title=\"Expert YaleZ\" class=\"rated-user user-blue\">YaleZ</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2014 22:38\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159842\" href=\"?#comment-159842\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"159842\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"159842\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"24526\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159842\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thank for timely editorial. I think Markdown is better when publish something on Github. Isn't it?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159842 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159842 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159842\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159846\" commentParentId=\"159842\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/cgy4ever\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2014 22:43\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159846\" href=\"?#comment-159846\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159842\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159846\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"11\"\r\n data-commentUserId=\"62\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+11</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159846\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Yes, I'm working on it. :)</p><p>The website seems to be not stable at this time. So I post them in other sites to ensure all people can see it.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159846 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159846 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159846\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159857\" commentParentId=\"159846\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Nodir.Daminov\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/71439/avatar/d6d2016f6dfe5ecd.jpg'/> </a>\n <div><a href=\"/profile/Nodir.Daminov\" title=\"Candidate Master Nodir.Daminov\" class=\"rated-user user-violet\">Nodir.Daminov</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2014 22:58\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159857\" href=\"?#comment-159857\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159846\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159857\" class=\"CommentVoteFrame\"\r\n class=\"too-negative-comment-vote\"\r\n data-commentRating=\"-35\"\r\n data-commentUserId=\"71439\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-35</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159857\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Maaan is it so hard to COPY ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159857 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159857 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159857\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159874\" commentParentId=\"159857\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/cgy4ever\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2014 23:19\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159874\" href=\"?#comment-159874\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159857\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159874\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"12\"\r\n data-commentUserId=\"62\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+12</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159874\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Sorry for the delay.</p><p>When I was submitting my post that contains the editorial, it always returns "Codeforces is now unavailable." so I just can't post it.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159874 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159874 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159874\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159859\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/BishalG\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/60637/avatar/d21ddf49bbd1630c.jpg'/> </a>\n <div><a href=\"/profile/BishalG\" title=\"Expert BishalG\" class=\"rated-user user-blue\">BishalG</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2014 22:58\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159859\" href=\"?#comment-159859\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159859\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"60637\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159859\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Nice problemSets @<a class=\"rated-user user-orange\" href=\"/profile/cgy4ever\" title=\"International Master cgy4ever\">cgy4ever</a> , although I misunderstood the problem-B <a href=\"/contest/389/problem/B\" title=\"Codeforces Round 228 (Div. 2)\">389B - Fox and Cross</a> upto 1 hrs :( </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159859 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159859 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159859\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159867\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Mr.ink\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Mr.ink\" title=\"Expert Mr.ink\" class=\"rated-user user-blue\">Mr.ink</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2014 23:07\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159867\" href=\"?#comment-159867\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159867\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"128876\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159867\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>due to my slow internet speed i can not see your editorial on github because my country internet has problem with https! </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159867 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159867 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159867\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159881\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Mr.ink\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Mr.ink\" title=\"Expert Mr.ink\" class=\"rated-user user-blue\">Mr.ink</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2014 23:38\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159881\" href=\"?#comment-159881\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159881\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"128876\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159881\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>does anyone have a better solution for div2 C problem?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159881 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159881 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159881\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159883\" commentParentId=\"159881\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/t_thirupathi\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/146179/avatar/98c28348196ce4ca.jpg'/> </a>\n <div><a href=\"/profile/t_thirupathi\" title=\"Specialist t_thirupathi\" class=\"rated-user user-cyan\">t_thirupathi</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2014 23:42\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159883\" href=\"?#comment-159883\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159881\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159883\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"146179\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159883\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Have a look at mine <a href=\"/contest/389/submission/5878414\" title=\"Submission 5878414 by t_thirupathi\">5878414</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159883 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159883 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159883\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159909\" commentParentId=\"159883\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/9charles\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/119814/avatar/653156a3153bc2dd.jpg'/> </a>\n <div><a href=\"/profile/9charles\" title=\"Expert 9charles\" class=\"rated-user user-blue\">9charles</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 06:46\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159909\" href=\"?#comment-159909\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159883\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159909\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"119814\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159909\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can you explain it?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159909 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159909 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159909\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159907\" commentParentId=\"159881\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/k790alex\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/119882/avatar/4baeddca65b2b958.jpg'/> </a>\n <div><a href=\"/profile/k790alex\" title=\"Specialist k790alex\" class=\"rated-user user-cyan\">k790alex</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 06:28\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159907\" href=\"?#comment-159907\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159881\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159907\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"119882\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159907\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I don't know if this is a better way but I didt in the contest.</p><p>Start making a pile with the low strength and while possible, look for a box that can support at least 1 box, then at least 2 boxes, 3, etc, repeat it while you have boxes.</p><p>My solution: <a href=\"/contest/389/submission/5879464\" title=\"Submission 5879464 by k790alex\">5879464</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159907 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159907 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159907\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159914\" commentParentId=\"159907\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/YaleZ\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/24526/avatar/5b17db1affad55a5.jpg'/> </a>\n <div><a href=\"/profile/YaleZ\" title=\"Expert YaleZ\" class=\"rated-user user-blue\">YaleZ</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 07:38\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159914\" href=\"?#comment-159914\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159907\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159914\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"24526\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159914\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Greedy is also a nice solution.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159914 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159914 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159914\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159932\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/worfzyq\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/157364/avatar/8f104a361ed91be8.jpg'/> </a>\n <div><a href=\"/profile/worfzyq\" title=\"Expert worfzyq\" class=\"rated-user user-blue\">worfzyq</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 09:52\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159932\" href=\"?#comment-159932\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159932\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"157364\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159932\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>388C — Fox and Card Game This problem is good magic</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159932 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159932 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159932\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159935\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/orchidmajumder\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/63603/avatar/f8db3747466a7168.jpg'/> </a>\n <div><a href=\"/profile/orchidmajumder\" title=\"Specialist orchidmajumder\" class=\"rated-user user-cyan\">orchidmajumder</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 10:07\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159935\" href=\"?#comment-159935\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"159935\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"159935\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"7\"\r\n data-commentUserId=\"63603\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+7</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159935\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>hii everyone,in Div II E,I can't understand why the optimal play for JIRO is to take the bottom most card from the same pile from where CIEL is picking?should not it try to pick the maximum value among all bottom most card at it's every move??</p><p>Please someone explain why the strategy presented in the editorial is optimal.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159935 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159935 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159935\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159948\" commentParentId=\"159935\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Zzyzx\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/86049/avatar/c698ee674460e7eb.jpg'/> </a>\n <div><a href=\"/profile/Zzyzx\" title=\"Expert Zzyzx\" class=\"rated-user user-blue\">Zzyzx</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 13:07\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159948\" href=\"?#comment-159948\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159935\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159948\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"86049\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159948\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Ok, I'm afraid I do not have a rigorous proof for this. I'll just explain to you why I think it is right.</p><p>First of all, we need to understand that both Ciel and Jiro are smart. Now, whenever it is Ciel's turn, he will pick the "best pile" and try to take everything from that pile and then move on to the next "best pile". Jiro knows that his friend Ciel is smart, so he will try to stop him from taking everything. This can be done only if he picks from the same pile that Ciel does.</p><p>But your question is — what if there is a different pile whose bottom-most card is much better than the bottom-most card of the pile from which Ciel is picking right?</p><p>My answer to this is that, this situation will never arise. Because if there is such a pile, then Ciel will try to take that card in the first place and therefore, Ciel will be picking from the same pile that Jiro will want to pick from.</p><p>Am I making sense? Or is there a flaw in my argument?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159948 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159948 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159948\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159952\" commentParentId=\"159948\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/orchidmajumder\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/63603/avatar/f8db3747466a7168.jpg'/> </a>\n <div><a href=\"/profile/orchidmajumder\" title=\"Specialist orchidmajumder\" class=\"rated-user user-cyan\">orchidmajumder</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 13:32\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159952\" href=\"?#comment-159952\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159948\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159952\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"63603\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159952\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Yes I'm also thinking along the same line.Both are playing optimally and if Ciel is chosing any pile then jiro knows that this pile has better cards in the botttom half.So he won't choose ciel to take the advantage and vice versa.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159952 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159952 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159952\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159944\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hzyfr\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/hzyfr\" title=\"Expert hzyfr\" class=\"rated-user user-blue\">hzyfr</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 12:27\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159944\" href=\"?#comment-159944\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159944\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"129936\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159944\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I have a different idea on D div1 <a href=\"/contest/388/problem/D\" title=\"Codeforces Round 228 (Div. 1)\">388D - Fox and Perfect Sets</a> but I failed on getting some relations in one step.</p><p>Let <em>M</em> be the maximum element in set <em>S</em> . Then if <em>S</em> is a perfect set, its elements should have all bits equals <em>0</em> on positions in <em>M's</em> binary representation(otherwise there must exist another element bigger than <em>M</em>). So let <em>cnt</em> = (number of 1's in binary repersentation of <em>M</em>), then the number of perfect sets which has <em>M</em> as its greatest element is determined by <em>cnt</em> . Well, this is the step I can't come up with a solution(actually the target is to find the number of perfect sets which has <code>2^cnt-1</code> as its greatest element).</p><p>Then the last step is simple. We can apply something like doubling algorithm on the problem.</p><p>We are asked to find the number of perfect sets with all the elements not greater than <em>N</em> . Let's suppose <em>N+1</em> is a power of 2 then its easy to calculate how many numbers not greater than <em>N</em> has <em>cnt</em> = 1,2,...m where m is the length of <em>N</em> in binary representation. That's just simple combinatoric number <em>C(n,i) (1<=i<=n)</em> . And if we have done the previous step, it's easy to get the result.</p><p>Then think about common cases of <em>N</em> . Let's take the highest bit of N and since all above bits are determined, the number of 1's will just add a constant value. So calculate this part and subtract that highest bit of <em>N</em> and do the same thing on remaining value of <em>N</em> , until <em>N=0</em> . At that time we will get the correct answer. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159944 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159944 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159944\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159945\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/rexdf\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/23738/avatar/797fa665fbe1ca78.jpg'/> </a>\n <div><a href=\"/profile/rexdf\" title=\"Specialist rexdf\" class=\"rated-user user-cyan\">rexdf</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 12:36\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159945\" href=\"?#comment-159945\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159945\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"23738\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159945\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>dp[1] = 1, dp[v] = sum{dp[t] | dist(1,t) = dist(1,v) — 1}, then dp[2] is our answer. What's v means? what's '|' means? What's dp[v] means?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159945 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159945 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159945\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159949\" commentParentId=\"159945\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/sancho\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/85894/avatar/e31a4b24327c1000.jpg'/> </a>\n <div><a href=\"/profile/sancho\" title=\"Candidate Master sancho\" class=\"rated-user user-violet\">sancho</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 13:10\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159949\" href=\"?#comment-159949\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159945\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159949\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"85894\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159949\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>v — vertex, answer for which we are getting at this moment, | — means "such as", dp[v] — number of ways from 1 vertex to this one</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159949 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159949 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159949\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159947\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lol12\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/lol12\" title=\"Specialist lol12\" class=\"rated-user user-cyan\">lol12</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 13:04\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159947\" href=\"?#comment-159947\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159947\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"10\"\r\n data-commentUserId=\"152356\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+10</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159947\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can someone please explain solution of Div2-D. Thanx</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159947 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159947 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159947\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"160020\" commentParentId=\"159947\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/YaleZ\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/24526/avatar/5b17db1affad55a5.jpg'/> </a>\n <div><a href=\"/profile/YaleZ\" title=\"Expert YaleZ\" class=\"rated-user user-blue\">YaleZ</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/05/2014 07:07\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-160020\" href=\"?#comment-160020\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159947\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"160020\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"9\"\r\n data-commentUserId=\"24526\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+9</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-160020\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>You can think about binnary. Such as (13)10=(1101)2=((1+(2+0)*2)+1)*2+1</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-160020 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-160020 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-160020\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"469976\" commentParentId=\"159947\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/roll_no_1\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/631859/avatar/36d157f91f64fe7f.jpg'/> </a>\n <div><a href=\"/profile/roll_no_1\" title=\"Master roll_no_1\" class=\"rated-user user-orange\">roll_no_1</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Nov/09/2018 17:27\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-469976\" href=\"?#comment-469976\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159947\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"469976\" revisionCount=\"4\" revision=\"4\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">4</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"469976\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"631859\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-469976\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Here's my implementation of the editorialist's explanation of Div-2 D / Div-1 B: <a href=\"/contest/388/submission/45480077\" title=\"Submission 45480077 by roll_no_1\">45480077</a>. I implemented the layers as [1], [1, 1], [2, 1, 1], [4, 2, 1, 1] and so on.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-469976 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-469976 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-469976\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159967\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/BENYAM1N\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/84938/avatar/d2ae2657d8898e38.jpg'/> </a>\n <div><a href=\"/profile/BENYAM1N\" title=\"Master BENYAM1N\" class=\"rated-user user-orange\">BENYAM1N</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 15:51\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159967\" href=\"?#comment-159967\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159967\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"13\"\r\n data-commentUserId=\"84938\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+13</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159967\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Very good contest and nice editorial. Hope from now on I see more contests from you.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159967 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159967 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159967\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159984\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/kojak_\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/57722/avatar/38990eea59bc188e.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/kojak_\" title=\"Newbie kojak_\" class=\"rated-user user-gray\">kojak_</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 18:34\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159984\" href=\"?#comment-159984\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159984\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"57722\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159984\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Did anyone come up with a DP solution for Div.2 C/ Div.1 A?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159984 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159984 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159984\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"160012\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/IgorKoval\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/51322/avatar/afc854fff49f072a.jpg'/> </a>\n <div><a href=\"/profile/IgorKoval\" title=\"Candidate Master IgorKoval\" class=\"rated-user user-violet\">IgorKoval</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 23:17\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-160012\" href=\"?#comment-160012\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"160012\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"11\"\r\n data-commentUserId=\"51322\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+11</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-160012\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Объясните, пожалуйста, разбор задачи "388D — Fox and Perfect Sets" на пальцах. Как-нибудь без Гаусса и базисов. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-160012 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-160012 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-160012\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"160016\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Mr.ink\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Mr.ink\" title=\"Expert Mr.ink\" class=\"rated-user user-blue\">Mr.ink</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/05/2014 01:08\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-160016\" href=\"?#comment-160016\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"160016\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"128876\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-160016\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>fox and card games is a great problem.thanks!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-160016 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-160016 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-160016\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"160037\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/yaswanth\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/yaswanth\" title=\"Specialist yaswanth\" class=\"rated-user user-cyan\">yaswanth</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/05/2014 18:38\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-160037\" href=\"?#comment-160037\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"160037\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"9\"\r\n data-commentUserId=\"96196\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+9</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-160037\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can anyone explain div2 C question? I did not understand the editorial.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-160037 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-160037 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-160037\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"160063\" commentParentId=\"160037\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/YaleZ\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/24526/avatar/5b17db1affad55a5.jpg'/> </a>\n <div><a href=\"/profile/YaleZ\" title=\"Expert YaleZ\" class=\"rated-user user-blue\">YaleZ</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/06/2014 05:46\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-160063\" href=\"?#comment-160063\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-160037\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"160063\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"24526\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-160063\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>s[i]>=i/k -> k*s[i]>=i There are i boxes' strength smaller than i-th box. So we need to check if the boxes before i-th can be held.</p><p>(I don't know whether I have understood correctly...)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-160063 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-160063 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-160063\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"160053\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/yada\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/142663/avatar/49901b54d1c5f019.jpg'/> </a>\n <div><a href=\"/profile/yada\" title=\"Candidate Master yada\" class=\"rated-user user-violet\">yada</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/05/2014 23:24\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-160053\" href=\"?#comment-160053\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"160053\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"142663\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-160053\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Great Problem! I really enjoy it.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-160053 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-160053 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-160053\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"364019\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lnzva\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/305672/avatar/cf6c09a214141751.jpg'/> </a>\n <div><a href=\"/profile/lnzva\" title=\"Expert lnzva\" class=\"rated-user user-blue\">lnzva</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/02/2017 22:06\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-364019\" href=\"?#comment-364019\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"364019\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"364019\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"305672\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-364019\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In 388C, I'm having a hard time understanding why Jiro's optimal strategy would be to pick the pile Ciel just picked. Why not pick a pile which has a better bottom part than the one Ciel is picking? According to some comments, Ciel would then pick from the second pile-what if another pile has a much better top part? Could someone please help? I saw this problem first 6 months ago, and I had a hard time understanding why this greedy is correct; I saw this problem again today and am having trouble with it again, with no progress.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-364019 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-364019 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-364019\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"647866\" commentParentId=\"364019\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/_wzx27\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1458283/avatar/7d77b62012ae2398.jpg'/> </a>\n <div><a href=\"/profile/_wzx27\" title=\"Candidate Master _wzx27\" class=\"rated-user user-violet\">_wzx27</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/22/2020 18:33\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-647866\" href=\"?#comment-647866\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-364019\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"647866\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1458283\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-647866\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Let's consider such a two-piles situation:</p><p><em>111100</em></p><p><em>001111</em></p><p>is better for Ciel.</p><p>"1" means this card is picked by Ciel,while "0" by Jiro.</p><p>We know that better for Ciel means worse for Jiro.</p><p>So if</p><p><em>111100</em></p><p><em>001111</em></p><p>is better than</p><p><em>111000</em></p><p><em>000111</em></p><p>for Ciel.</p><p>Then when Ciel picked the <strong>first three cards</strong> from <strong>pile 1</strong>,Jiro can just pick the <strong>last three cards</strong> from <strong>pile 1</strong> and finally lead to the result:</p><p><em>111000</em></p><p><em>000111</em></p><p>which is not better for Ciel.</p><p>Generally, if the final result is not balance(half from top and half from bottom) while balance is better than such result for Jiro, Jiro has the ability to adjust it to be balance.So do Ciel.</p><p>Therefore,it reaches balance.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-647866 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-647866 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-647866\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"407776\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/madhur4127\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/568692/avatar/c7d62cc23c758819.jpg'/> </a>\n <div><a href=\"/profile/madhur4127\" title=\"Specialist madhur4127\" class=\"rated-user user-cyan\">madhur4127</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/15/2018 13:06\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-407776\" href=\"?#comment-407776\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"407776\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"568692\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-407776\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>@<a class=\"rated-user user-red\" href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\">cgy4ever</a>, github link shows 404 error(Page not found). Kindly fix it.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-407776 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-407776 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-407776\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"416354\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/introverted\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/657339/avatar/7a6edb1ecc1d3e09.jpg'/> </a>\n <div><a href=\"/profile/introverted\" title=\"Expert introverted\" class=\"rated-user user-blue\">introverted</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/23/2018 11:48\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-416354\" href=\"?#comment-416354\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"416354\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"657339\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-416354\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I solved the DIV1B problem with simple recursion and Divide and Conquer.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-416354 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-416354 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-416354\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"427890\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Nuu\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/652228/avatar/d59867d6477379dc.jpg'/> </a>\n <div><a href=\"/profile/Nuu\" title=\"Candidate Master Nuu\" class=\"rated-user user-violet\">Nuu</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/01/2018 22:33\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-427890\" href=\"?#comment-427890\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"427890\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"652228\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-427890\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can anyone give me some examples of the similar problems to DivC?? I think this problem is very nice for train brain xD</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-427890 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-427890 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-427890\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"629609\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/The_Alchemist\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1275181/avatar/662970aa05d3dfc5.jpg'/> </a>\n <div><a href=\"/profile/The_Alchemist\" title=\"Expert The_Alchemist\" class=\"rated-user user-blue\">The_Alchemist</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/25/2020 21:47\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-629609\" href=\"?#comment-629609\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"629609\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1275181\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-629609\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I know I am very late but can someone pls explain to me div 2C/div1A. Thanks in advance... </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-629609 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-629609 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-629609\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"641010\" commentParentId=\"629609\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/kstheking\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1160931/avatar/e144fc7b0fdb90b1.jpg'/> </a>\n <div><a href=\"/profile/kstheking\" title=\"Pupil kstheking\" class=\"rated-user user-green\">kstheking</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/13/2020 14:47\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-641010\" href=\"?#comment-641010\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-629609\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"641010\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1160931\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-641010\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p><a href=\"https://codeforces.com/contest/388/submission/83605110\">https://codeforces.com/contest/388/submission/83605110</a> Here you go, if you don't get it feel free to ask</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-641010 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-641010 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-641010\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"644488\" commentParentId=\"641010\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/tanisha_\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/tanisha_\" title=\"Newbie tanisha_\" class=\"rated-user user-gray\">tanisha_</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/18/2020 15:26\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-644488\" href=\"?#comment-644488\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-641010\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"644488\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1500127\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-644488\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>is this any algorithm</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-644488 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-644488 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-644488\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"647627\" commentParentId=\"644488\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/kstheking\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1160931/avatar/e144fc7b0fdb90b1.jpg'/> </a>\n <div><a href=\"/profile/kstheking\" title=\"Pupil kstheking\" class=\"rated-user user-green\">kstheking</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/22/2020 08:40\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-647627\" href=\"?#comment-647627\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-644488\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"647627\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"647627\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1160931\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-647627\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Well you can call it a greedy algorithm, when we try to apply greedy by placing the heaviest block in bottom, a little problem occurs because of blocks of same strength for example in case of 10 2 2 1 1 0 0<br />If you try to apply greedy by choosing the strongest block<br />10 2 2 1<br />1 0<br />0<br />= 3 heaps<br />Which is wrong answer as sometimes we lose opportunity to create lesser heaps, as in this case if we use the second 2 to make another heap we can do better<br />10 2 1 0<br />2 1 0<br />= 2 heaps<br />So I apply greedy in the reverse direction by picking the smallest strength brick and placing below it the next smallest brick, this way the optimal number of heaps will be formed as in above example<br />choose 0, then you need >= 1, choose 1, then you need >= 2, choose 2, then you need >= 3 choose 10<br />repeat until you have chosen all the bricks<br />If you don't get anything, feel free to ask :) </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-647627 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-647627 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-647627\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"702677\" commentParentId=\"647627\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/breddreamer\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/853067/avatar/240684624b57996.jpg'/> </a>\n <div><a href=\"/profile/breddreamer\" title=\"Newbie breddreamer\" class=\"rated-user user-gray\">breddreamer</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/27/2020 13:01\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-702677\" href=\"?#comment-702677\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-647627\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"702677\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"853067\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-702677\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks, It helped me to understand your solution idea. And finally, I solved this one.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-702677 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-702677 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-702677\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"649225\" commentParentId=\"641010\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/The_Alchemist\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1275181/avatar/662970aa05d3dfc5.jpg'/> </a>\n <div><a href=\"/profile/The_Alchemist\" title=\"Expert The_Alchemist\" class=\"rated-user user-blue\">The_Alchemist</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/24/2020 12:04\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-649225\" href=\"?#comment-649225\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-641010\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"649225\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1275181\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-649225\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>thank you.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-649225 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-649225 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-649225\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n <br/>\r\n\r\n<div id=\"editBox-10700\" style=\"width:50em;display:none;\">\r\n <div class=\"previewBody\" style=\"border: 1px solid #d4d4d4; margin-bottom: 0.5em; padding: 0.25em; display:none;\"> </div>\r\n <div style=\"width: 1px\"> </div>\r\n <div class=\"commentLocale\" style=\"position: relative; top: 0.5em;left:4px;display: none;\">\r\n <input type=\"radio\" name=\"locale\" value=\"en\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In English</span>\r\n <input style=\"margin-left:1em\" type=\"radio\" name=\"locale\" value=\"ru\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In Russian</span>\r\n </div>\r\n <textarea data-drafts-id=\"CommentReplyFrame\" class=\"wysiwyg\" name=\"editContent\" rows=\"20\" style=\"width:99%;\"></textarea>\r\n <div class=\"error error__content\"></div>\r\n <div style=\"text-align:center;\">\r\n <input type=\"button\" name=\"preview\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Preview\"/>\r\n <input type=\"button\" name=\"save\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Save\"/>\r\n </div>\r\n</div>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n\r\nvar firstPreview10700 = true;\r\nvar lastPreviewContent10700 = '';\r\n\r\nif (!window.moveCommentRevision) {\r\n moveCommentRevision = function(e, dir) {\r\n var p = e.parent();\r\n var revisionCount = parseInt(p.attr(\"revisionCount\"));\r\n var revision = parseInt(p.attr(\"revision\"));\r\n var next = revision + dir;\r\n var commentId = p.attr(\"commentId\");\r\n if (next >= 1 && next <= revisionCount) {\r\n $.post(\r\n \"/data/comment-data\",\r\n {action: \"revision\", commentId: commentId, revision: next},\r\n function(json) {\r\n if (json.success == \"true\") {\r\n var parentDiv = e;\r\n\r\n while (parentDiv !== null && (parentDiv[0].nodeName.toLowerCase() !== \"td\" || !parentDiv.hasClass(\"right\"))) {\r\n parentDiv = parentDiv.parent();\r\n }\r\n\r\n if (parentDiv === null) {\r\n return;\r\n }\r\n\r\n parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\").html(json.content);\r\n Codeforces.setupSpoilers(parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\"));\r\n p.attr(\"revision\", next);\r\n p.find(\"span.revision\").text(next);\r\n if (next == 1) {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"visible\");\r\n }\r\n if (next == revisionCount) {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"visible\");\r\n }\r\n\r\n window.updateTypography();\r\n MathJax.Hub.Typeset();\r\n } else {\r\n alert(e.error);\r\n }\r\n },\r\n \"json\"\r\n );\r\n }\r\n };\r\n}\r\n\r\n$(\"div[commentableId=10700] a.leftRevision\").click(function () {\r\n window.moveCommentRevision($(this), -1);\r\n return false;\r\n});\r\n\r\n$(\"div[commentableId=10700] a.rightRevision\").click(function () {\r\n window.moveCommentRevision($(this), +1);\r\n return false;\r\n});\r\n\r\n\r\n\r\n });\n </script>\n\r\n\r\n <script src=\"//codeforces.org/s/81027/js/swfobject-2.2.min.js\" type=\"text/javascript\"></script>\n <script src=\"//codeforces.org/s/81027/js/ftaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n if (window.evercookie) {\n var ec = new evercookie({\n history: false,\n silverlight: false,\n baseurl: '',\n asseturi: '/assets',\n phpuri: '/2fdcd78',\n pngPath: '/eps',\n etagPath: '/ees',\n cachePath: '/ecs'\n });\n\n var randomNumber = function () {\n return Math.random().toString(36).substr(2);\n };\n\n var randomToken = function () {\n return (randomNumber() + randomNumber()).substring(0, 18);\n };\n\n window._ftaa = \"\";\n\n ec.get(\"70a7c28f3de\", function (value) {\n window._ftaa = value;\n if (!window._ftaa) {\n window._ftaa = randomToken();\n ec.set(\"70a7c28f3de\", window._ftaa);\n }\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n } else {\n window._ftaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\n <script src=\"//codeforces.org/s/81027/js/bfaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n var fpCallback = function() {\n Fingerprint2.get({}, function(components) {\n window._bfaa = Fingerprint2.x64hash128(components.map(function (pair) { return pair.value }).join(), 31);\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n };\n if (typeof Fingerprint2 !== 'undefined') {\n if (window.requestIdleCallback) {\n requestIdleCallback(fpCallback)\n } else {\n setTimeout(fpCallback, 500)\n }\n } else {\n window._bfaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"a.new-root-comment\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n\r\n $(\".comment-table .reply a\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".vote-for-comment\").mouseover(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").mouseout(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").click(function () {\r\n var vote = $(this);\r\n var commentId = $(this).parent().attr(\"commentid\");\r\n var commentRating = $(this).parent().attr(\"data-commentRating\");\r\n var direction = $(this).attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n $.post(\"/data/comment/vote\", {commentId: commentId, _tta: Codeforces.tta(), vote: direction, commentRating: commentRating}, function(data) {\r\n if (direction != 0 && !ownComment && data[\"success\"] == \"true\") {\r\n vote.parent().find(\".vote-for-comment\").attr(\"voteDirection\", 0);\r\n if (direction == 1)\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n else {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.closest(\".CommentVoteFrame\").find(\".ComplaintFrame\").css(\"display\", \"inline-block\");\r\n }\r\n vote.find(\"img\").attr(\"popacity\", \"1.0\");\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n vote.parent().find(\".commentRating\").html(data[\"commentRating\"]);\r\n }\r\n Codeforces.showMessage(data[\"message\"]);\r\n }, \"json\");\r\n return false;\r\n });\r\n\r\n $(\".negative-comment-vote\").closest(\".comment-table\").addClass(\"comment-bad\");\r\n\r\n $(\".troll-comment-vote\").closest(\".comment\").css(\"display\", \"none\");\r\n\r\n $(\".too-negative-comment-vote\").closest(\".comment-table\").each(function () {\r\n var e = $(this);\r\n e.addClass(\"comment-too-bad\");\r\n var commentId = e.attr(\"commentId\");\r\n $(\"<div class='bad-comment-replacement ttypography'>The comment is hidden because of too negative feedback, click <a href=# class=show-bad-comment-link>here</a> to view it</div>\").appendTo(\r\n e.find(\".right\")\r\n );\r\n e.find(\".comment-content\").hide();\r\n e.find(\".show-bad-comment-link\").click(function () {\r\n e.find(\".comment-content\").show();\r\n e.find(\".bad-comment-replacement\").hide();\r\n return false;\r\n });\r\n });\r\n });\n </script>\n </div>\r\n\r\n <style type=\"text/css\">\r\n .new-comments-box {\r\n padding: 0.5em;\r\n width: 22px;\r\n font-size: 1.3rem;\r\n font-weight: bold !important;\r\n\r\n position: fixed;\r\n top: 40%;\r\n right: 0;\r\n opacity: 0.2;\r\n color: white;\r\n text-align: center;\r\n\r\n border: 1px solid #222;\r\n background-color: #888 !important;\r\n border-radius: 3px;\r\n -moz-border-radius: 3px;\r\n -webkit-border-radius: 3px;\r\n }\r\n\r\n .new-comments-box:hover {\r\n opacity: 1;\r\n }\r\n\r\n .new-comments-box .dir:hover {\r\n background: #3B5998 !important;\r\n cursor: pointer;\r\n }\r\n </style>\r\n\r\n <div class=\"new-comments-box\" data-position=\"outside\" data-index=\"-1\" style=\"display: none;\">\r\n <div class=\"up dir\" title=\"Ctrl+Up\">↑<hr/>\r\n </div>\r\n <div class=\"info\" title=\"New comments\"></div>\r\n <div class=\"down dir\" title=\"Ctrl+Down\">\r\n <hr/>↓\r\n </div>\r\n </div>\r\n\r\n <script>\r\n $(\".show-archived-checkbox\").change(function () {\r\n const checked = $(this).is(\":checked\");\r\n $.post(\"/data/comment-data\", {action: \"setShowArchived\", checked}, function (json) {\r\n if (json[\"success\"] !== \"true\") {\r\n alert(json[\"error\"]);\r\n } else {\r\n if (checked) {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are now displayed\")\r\n } else {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are no longer displayed\")\r\n }\r\n }\r\n });\r\n return false;\r\n });\r\n\r\n function gotoComment(direction) {\r\n var box = $(\".new-comments-box\");\r\n var index = parseInt(box.attr(\"data-index\"));\r\n if (index == -1)\r\n index = 0;\r\n else\r\n index = Math.max(0, Math.min(parseInt(box.find(\".info\").text()) - 1, index + direction));\r\n box.attr(\"data-index\", index);\r\n var comment = $($(\".comment .highlight-blue[commentId]\").get(index));\r\n $('html, body').animate({\r\n 'scrollTop': Math.max(0, comment.offset().top - ($(window).height() - comment.height()) / 2)\r\n });\r\n return false;\r\n }\r\n\r\n $(\".new-comments-box .down\").click(function () {\r\n return gotoComment(1);\r\n });\r\n\r\n $(\".new-comments-box .up\").click(function () {\r\n return gotoComment(-1);\r\n });\r\n\r\n $(document).keydown(function (e) {\r\n var code = (e.keyCode ? e.keyCode : e.which);\r\n if (e.ctrlKey) {\r\n if (code == 38 || code == 40) {\r\n gotoComment(code - 39);\r\n }\r\n }\r\n });\r\n\r\n var newCommentCount = $(\".comment .highlight-blue[commentId]\").length;\r\n if (newCommentCount > 0) {\r\n $(\".new-comments-box .info\").text(newCommentCount);\r\n $(\".new-comments-box\").show();\r\n }\r\n\r\n $('table.comment-table').mouseenter(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").addClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n\r\n $('table.comment-table').mouseleave(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").removeClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n </script>\r\n\r\n\r\n\r\n <script>\r\n function adjustTopicComplainFrames() {\r\n let topicIds = [];\r\n\r\n $(\".has-topic-id\").each(function () {\r\n const $this = $(this);\r\n const topicId = $this.attr(\"topicId\");\r\n if (topicId) {\r\n topicIds.push(topicId);\r\n }\r\n });\r\n\r\n $.post(\"/data/topics\", {\r\n action: \"findComplainableTopicIds\",\r\n topicIds: topicIds.join(\",\")\r\n }, function (json) {\r\n if (json[\"success\"] === \"true\") {\r\n for (const topicId of json[\"complainableTopicIds\"].split(\",\")) {\r\n $(\".has-topic-id[topicId=\" + topicId + \"]\").each(function () {\r\n $(this).find(\".meta .ComplaintFrame\").css(\"display\", \"inline-block\");\r\n });\r\n }\r\n }\r\n }, \"json\");\r\n }\r\n\r\n $(function () {\r\n adjustTopicComplainFrames();\r\n })\r\n </script>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-10684\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 10684, _tta: Codeforces.tta(), topicRevisionId: 36670, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-10684\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 10684, _tta: Codeforces.tta(), topicRevisionId: 36670, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n </div>\r\n </div>\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 22:13:07</span> (h1).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/81027/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/81027/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/81027/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/81027/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-81027.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'812875a2ab4016f4',t:'MTY5NjcwNTk4Ny4yMjQwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"}}},{"rowIdx":1961,"cells":{"problem_id":{"kind":"string","value":"388D"},"contest":{"kind":"string","value":"388"},"problem":{"kind":"string","value":"D"},"lang":{"kind":"string","value":"en"},"problem_title":{"kind":"string","value":"D. Fox and Perfect Sets"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">D. Fox and Perfect Sets</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Fox Ciel studies number theory.</p><p>She thinks a non-empty set <span class=\"tex-span\"><i>S</i></span> contains non-negative integers is <span class=\"tex-font-style-it\">perfect</span> if and only if for any <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/9ef9929d40fa162bdd76a55da469dde6fc13a5f5.png\" style=\"max-width: 100.0%;max-height: 100.0%;\"/> (<span class=\"tex-span\"><i>a</i></span> can be equal to <span class=\"tex-span\"><i>b</i></span>), <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/bba2b10c821617f53f33d4f198ad3dfee0eb6ecd.png\" style=\"max-width: 100.0%;max-height: 100.0%;\"/>. Where operation <span class=\"tex-span\"><i>xor</i></span> means exclusive or operation (<span class=\"tex-font-style-it\">http://en.wikipedia.org/wiki/Exclusive_or</span>).</p><p>Please calculate the number of perfect sets consisting of integers not greater than <span class=\"tex-span\"><i>k</i></span>. The answer can be very large, so print it modulo <span class=\"tex-span\">1000000007</span> <span class=\"tex-span\">(10<sup class=\"upper-index\">9</sup> + 7)</span>.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains an integer <span class=\"tex-span\"><i>k</i></span> (<span class=\"tex-span\">0 ≤ <i>k</i> ≤ 10<sup class=\"upper-index\">9</sup></span>).</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print a single integer — the number of required sets modulo <span class=\"tex-span\">1000000007</span> <span class=\"tex-span\">(10<sup class=\"upper-index\">9</sup> + 7)</span>.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>1<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>2<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>2<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>3<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>5<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>4<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>6<br/></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>In example 1, there are 2 such sets: {0} and {0, 1}. Note that {1} is not a perfect set since 1 xor 1 = 0 and {1} doesn't contain zero.</p><p>In example 4, there are 6 such sets: {0}, {0, 1}, {0, 2}, {0, 3}, {0, 4} and {0, 1, 2, 3}.</p></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"d5fe8a843e299558fb2d96b8570031b4\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - D - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"fe71135886e33994ae4d9b5e4703fc32ee0c7819\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - D - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/73366/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/73366/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/73366/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/73366/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/73366/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/73366/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/73366/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/73366/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/73366/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/73366/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/73366/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/73366/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/73366/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/73366/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/sidebar-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/a037fe51637846d9c7c725713cd840ea/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='d5fe8a843e299558fb2d96b8570031b4'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/73366/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/73366/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fcontest%2F388%2Fproblem%2FD%3Flocale%3Den\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"current\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='d5fe8a843e299558fb2d96b8570031b4'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:100%;\"><a style=\"color: black\" href=\"/contest/388\">Codeforces Round 228 (Div. 1)</a></th>\n </tr>\n <tr>\n <td class=\"left bottom\" colspan=\"1\"><span class=\"contest-state-phase\">Finished</span></td>\n </tr>\n </tbody>\n </table>\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Practice?\n <div class=\"top-links\">\n </div>\n </div>\n<div>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Want to solve the contest problems after the official contest ends? Just register for practice and you will be able to submit solutions.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"\" method=\"post\"><input type='hidden' name='csrf_token' value='d5fe8a843e299558fb2d96b8570031b4'/>\r\n <input type=\"hidden\" name=\"action\" value=\"registerForPractice\"/>\r\n <input type=\"submit\" name=\"submit\" value=\"Register for practice\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div> \r\n</div>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox ContestVirtualFrame borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Virtual participation <i class=\"sidebar-caption-icon las la-angle-down\"></i>\r\n\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\" \"\r\n\r\n data-page-url=\"/data/sidebarFrames\"\r\n\r\n>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests.\n\nIf you've seen these problems, a virtual contest is not for you - solve these problems in the archive.\n\nIf you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.\n\nNever use someone else's code, read the tutorials or communicate with other person during a virtual contest.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"/contest/388/virtual\" method=\"get\">\r\n <input type=\"submit\" name=\"submit\" value=\"Start virtual contest\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div>\r\n</div>\r\n <script>\r\n $(function () {\r\n $(\".ContestVirtualFrame .sidebar-caption-icon\").click(function() {\r\n $(this).toggleClass(\"la-angle-down la-angle-right\");\r\n const $target = $(this).parent().next();\r\n $target.toggle();\r\n const dataPageUrl = $target.attr(\"data-page-url\");\r\n const collapsed = $(this).hasClass(\"la-angle-right\");\r\n const params = {\r\n action: \"setCollapsed\",\r\n sidebarFrameSimpleClassName: \"ContestVirtualFrame\",\r\n collapsed\r\n };\r\n $.each($target[0].attributes, function(i, a) {\r\n const name = a.name;\r\n if (name.startsWith(\"data-extra-key-\")) {\r\n const key = a.value;\r\n const keyIndex = parseInt(name.substring(\"data-extra-key-\".length));\r\n const value = $target.attr(\"data-extra-value-\" + keyIndex);\r\n params[key] = value;\r\n }\r\n });\r\n $.post(dataPageUrl, params, function (result) {\r\n if (result[\"success\"] !== \"true\") {\r\n Codeforces.showMessage(\"Failed to save collapsed state.\");\r\n }\r\n }, \"json\");\r\n return false;\r\n });\r\n })\r\n </script>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Problem tags\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Mathematics including integration, differential equations, etc\">\r\n math\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Difficulty\">\r\n *2700\r\n</span>\r\n </div>\n <div style=\"clear:both;text-align:right;font-size:1.1rem;\">\r\n <span title=\"Please login into the Codeforces\" class=\"notice\">No tag edit access</span>\r\n </div>\r\n</div>\r\n </div>\n\r\n<form id=\"addTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='d5fe8a843e299558fb2d96b8570031b4'/>\r\n <input name=\"action\" type=\"hidden\" value=\"addTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"6408\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<form id=\"removeTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='d5fe8a843e299558fb2d96b8570031b4'/>\r\n <input name=\"action\" type=\"hidden\" value=\"removeTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"6408\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<script type=\"text/javascript\">\r\n $(\".tag-box img\").click(function () {\r\n var tagName = $(this).attr(\"value\");\r\n Codeforces.confirm(\"Are you sure you want to remove this tag?\", function () {\r\n $(\"#removeTagForm input[name=tagName]\").val(tagName);\r\n $(\"#removeTagForm\").submit();\r\n }, function () {\r\n }, \"Yes\", \"No\");\r\n });\r\n\r\n $(\"#addTagLink\").click(function () {\r\n $(this).hide();\r\n $(\"#addTagLabel\").show();\r\n return false;\r\n });\r\n\r\n $(\"#addTagSelect\").change(function () {\r\n var tagName = $(this).val();\r\n if (tagName === \"\") {\r\n $(\"#addTagLabel\").hide();\r\n $(\"#addTagLink\").show();\r\n } else {\r\n $(\"#addTagForm input[name=tagName]\").val(tagName);\r\n $(\"#addTagForm\").submit();\r\n }\r\n });\r\n</script>\r\n\r\n<style type=\"text/css\">\r\n#new-resource-form tr td {\r\npadding-top: 0.5em;\r\n}\r\n#new-resource-form input:not([type=\"submit\"]) {\r\nfont-size: 0.8em;\r\n}\r\n#new-resource-form select {\r\nfont-size: 0.8em;\r\n}\r\n.new-resource-error {\r\nfont-size: 0.8em;\r\n}\r\n.resource-locale {\r\ncolor: #666;\r\nfont-family: Consolas, \"Andale Mono WT\", \"Andale Mono\", \"Lucida Console\", \"Lucida Sans Typewriter\", \"DejaVu Sans Mono\", \"Bitstream Vera Sans Mono\", \"Liberation Mono\", \"Nimbus Mono L\", Monaco, \"Courier New\", Courier, monospace;\r\n}\r\n</style>\r\n<div class=\"roundbox sidebox sidebar-menu borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Contest materials\n<div class=\"top-links\">\n</div>\n</div>\n<ul>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/10605\" title=\"Codeforces Round #228\" target=\"_blank\">Codeforces Round #228</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"2187:2188\" resourceName=\"Announcement\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/10629\" title=\"Codeforces Round #228 — Editorial\" target=\"_blank\">Tutorial <span class=\"resource-locale\">(en)</span></a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"2192\" resourceName=\"Codeforces Round #228 — Editorial\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n</ul>\r\n</div></div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li class=\"current selectedLava\"><a\r\n href=\"/contest/388\">Problems</a></li>\r\n <li><a\r\n href=\"/contest/388/submit\">Submit Code</a></li>\r\n <li><a\r\n href=\"/contest/388/my\">My Submissions</a></li>\r\n <li><a\r\n href=\"/contest/388/status\">Status</a></li>\r\n <li><a\r\n href=\"/contest/388/hacks\">Hacks</a></li>\r\n <li><a\r\n href=\"/contest/388/room/1\">Room</a></li>\r\n <li><a\r\n href=\"/contest/388/standings\">Standings</a></li>\r\n <li><a\r\n href=\"/contest/388/customtest\">Custom Invocation</a></li>\r\n</ul>\r\n</div>\n\r\n <style>\r\n #facebox .content:has(.diff-popup) {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n }\r\n\r\n .testCaseMarker {\r\n position: absolute;\r\n font-weight: bold;\r\n font-size: 1rem;\r\n }\r\n\r\n .diff-popup {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n display: none;\r\n overflow: auto;\r\n }\r\n\r\n .input-output-copier {\r\n font-size: 1.2rem;\r\n float: right;\r\n color: #888 !important;\r\n cursor: pointer;\r\n border: 1px solid rgb(185, 185, 185);\r\n padding: 3px;\r\n margin: 1px;\r\n line-height: 1.1rem;\r\n text-transform: none;\r\n }\r\n\r\n .input-output-copier:hover {\r\n background-color: #def;\r\n }\r\n\r\n .test-explanation textarea {\r\n width: 100%;\r\n height: 1.5em;\r\n }\r\n\r\n .pending-submission-message {\r\n color: darkorange !important;\r\n }\r\n </style>\r\n <script>\r\n const OPENING_SPACE = String.fromCharCode(1001);\r\n const CLOSING_SPACE = String.fromCharCode(1002);\r\n\r\n const nodeToText = function (node, pre) {\r\n let result = [];\r\n\r\n if (node.tagName === \"SCRIPT\" || node.tagName === \"math\"\r\n || (node.classList && node.classList.contains(\"input-output-copier\")))\r\n return [];\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(OPENING_SPACE);\r\n }\r\n\r\n if (node.nodeType === Node.TEXT_NODE) {\r\n let s = node.textContent;\r\n if (!pre) {\r\n s = s.replace(/\\s+/g, \" \");\r\n }\r\n if (s.length > 0) {\r\n result.push(s);\r\n }\r\n }\r\n\r\n if (pre && node.tagName === \"BR\") {\r\n result.push(\"\\n\");\r\n }\r\n\r\n node.childNodes.forEach(function (child) {\r\n result.push(nodeToText(child, node.tagName === \"PRE\").join(\"\"));\r\n });\r\n\r\n if (node.tagName === \"DIV\"\r\n || node.tagName === \"P\"\r\n || node.tagName === \"PRE\"\r\n || node.tagName === \"UL\"\r\n || node.tagName === \"LI\"\r\n ) {\r\n result.push(\"\\n\");\r\n }\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(CLOSING_SPACE);\r\n }\r\n\r\n return result;\r\n }\r\n\r\n const isSpecial = function (c) {\r\n return c === ',' || c === '.' || c === ';' || c === ')' || c === ' ';\r\n }\r\n\r\n const convertStatementToText = function(statmentNode) {\r\n const text = nodeToText(statmentNode, false).join(\"\").replace(/ +/g, \" \").replace(/\\n\\n+/g, \"\\n\\n\");\r\n let result = [];\r\n for (let i = 0; i < text.length; i++) {\r\n const c = text.charAt(i);\r\n if (c === OPENING_SPACE) {\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"D\" data-uuid=\"ps_d1d0b355071ad90d7b512544386032ede0b6370e\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">D. Fox and Perfect Sets</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Fox Ciel studies number theory.</p><p>She thinks a non-empty set <span class=\"tex-span\"><i>S</i></span> contains non-negative integers is <span class=\"tex-font-style-it\">perfect</span> if and only if for any <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/9ef9929d40fa162bdd76a55da469dde6fc13a5f5.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> (<span class=\"tex-span\"><i>a</i></span> can be equal to <span class=\"tex-span\"><i>b</i></span>), <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/bba2b10c821617f53f33d4f198ad3dfee0eb6ecd.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. Where operation <span class=\"tex-span\"><i>xor</i></span> means exclusive or operation (<span class=\"tex-font-style-it\">http://en.wikipedia.org/wiki/Exclusive_or</span>).</p><p>Please calculate the number of perfect sets consisting of integers not greater than <span class=\"tex-span\"><i>k</i></span>. The answer can be very large, so print it modulo <span class=\"tex-span\">1000000007</span> <span class=\"tex-span\">(10<sup class=\"upper-index\">9</sup> + 7)</span>.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains an integer <span class=\"tex-span\"><i>k</i></span> (<span class=\"tex-span\">0 ≤ <i>k</i> ≤ 10<sup class=\"upper-index\">9</sup></span>).</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print a single integer — the number of required sets modulo <span class=\"tex-span\">1000000007</span> <span class=\"tex-span\">(10<sup class=\"upper-index\">9</sup> + 7)</span>.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>1<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>2<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>2<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>3<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>5<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>4<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>6<br /></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>In example 1, there are 2 such sets: {0} and {0, 1}. Note that {1} is not a perfect set since 1 xor 1 = 0 and {1} doesn't contain zero.</p><p>In example 4, there are 6 such sets: {0}, {0, 1}, {0, 2}, {0, 3}, {0, 4} and {0, 1, 2, 3}.</p></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=D]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== statementText) {\r\n $problem.find(\".diff-notifier\").show();\r\n\r\n $problem.find(\".diff-notifier-close\").click(function() {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n $problem.find(\".diff-notifier\").hide();\r\n });\r\n\r\n $problem.find(\"a.view-changes\").click(function() {\r\n $.post(\"/data/diff\", {action: \"getDiff\", a: previousStatementText, b: statementText}, function (result) {\r\n if (result[\"success\"] === \"true\") {\r\n Codeforces.facebox(\".diff-popup\", \"//codeforces.org/s/73366\");\r\n $(\"#facebox .diff-popup\").html(result[\"diff\"]);\r\n }\r\n }, \"json\");\r\n });\r\n }\r\n } else {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n }\r\n });\r\n });\r\n </script>\r\n\r\n\r\n<script type=\"text/javascript\">\r\n $(document).ready(function () {\r\n window.changedTests = new Set();\r\n\r\n function endsWith(string, suffix) {\r\n return string.indexOf(suffix, string.length - suffix.length) !== -1;\r\n }\r\n\r\n const inputFileDiv = $(\"div.input-file\");\r\n const inputFile = inputFileDiv.text();\r\n const outputFileDiv = $(\"div.output-file\");\r\n const outputFile = outputFileDiv.text();\r\n\r\n\r\n if (!endsWith(inputFile, \"standard input\")\r\n && !endsWith(inputFile, \"standard input\")) {\r\n inputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n if (!endsWith(outputFile, \"standard output\")\r\n && !endsWith(outputFile, \"standard output\")) {\r\n outputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n const titleDiv = $(\"div.header div.title\");\r\n\r\n\r\n\r\n String.prototype.replaceAll = function (search, replace) {\r\n return this.split(search).join(replace);\r\n };\r\n\r\n $(\".sample-test .title\").each(function () {\r\n const preId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n const cpyId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n\r\n $(this).parent().find(\"pre\").attr(\"id\", preId);\r\n const $copy = $(\"<div title='Copy' data-clipboard-target='#\" + preId + \"' id='\" + cpyId + \"' class='input-output-copier'>Copy</div>\");\r\n $(this).append($copy);\r\n\r\n const clipboard = new Clipboard('#' + cpyId, {\r\n text: function (trigger) {\r\n const pre = document.querySelector('#' + preId);\r\n const lines = pre.querySelectorAll(\".test-example-line\");\r\n return Codeforces.filterClipboardText(pre.innerText, lines.length);\r\n }\r\n });\r\n\r\n const isInput = $(this).parent().hasClass(\"input\");\r\n\r\n clipboard.on('success', function (e) {\r\n if (isInput) {\r\n Codeforces.showMessage(\"The example input has been copied into the clipboard\");\r\n } else {\r\n Codeforces.showMessage(\"The example output has been copied into the clipboard\");\r\n }\r\n e.clearSelection();\r\n });\r\n });\r\n\r\n $(\".test-form-item input\").change(function () {\r\n addPendingSubmissionMessage($($(this).closest(\"form\")), \"You changed the answer, do not forget to submit it if you want to save the changes\");\r\n const index = $(this).closest(\".problemindexholder\").attr(\"problemindex\");\r\n let test = \"\";\r\n $(this).closest(\"form input\").each(function () {\r\n const test_ = $(this).attr(\"name\");\r\n if (test_ && test_.substring(0, 4) === \"test\") {\r\n test = test_;\r\n }\r\n });\r\n if (index.length > 0 && test.length > 0) {\r\n const indexTest = index + \"::\" + test;\r\n window.changedTests.add(indexTest);\r\n }\r\n });\r\n\r\n $(window).on('beforeunload', function () {\r\n if (window.changedTests.size > 0) {\r\n return 'Dialog text here';\r\n }\r\n });\r\n\r\n autosize($('.test-explanation textarea'));\r\n\r\n $(\".test-example-line\").hover(function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n let top = 1E20;\r\n let left = 1E20;\r\n let problem = $(this).closest(\".problemindexholder\");\r\n $(this).closest(\".input\").find(\".\" + clazz).css(\"background-color\", \"#FFFDE7\").each(function() {\r\n top = Math.min(top, $(this).offset().top);\r\n left = Math.min(left, $(this).offset().left);\r\n });\r\n let testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n if (testCaseMarker.length === 0) {\r\n const html = \"<div class=\\\"testCaseMarker testCaseMarker_\" + end + \" notice\\\"></div>\";\r\n problem.append($(html));\r\n testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n }\r\n if (testCaseMarker) {\r\n testCaseMarker.show()\r\n .offset({top, left: left - 20})\r\n .text(end);\r\n }\r\n }\r\n }\r\n });\r\n }, function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n $(\".\" + clazz).css(\"background-color\", \"\");\r\n $(this).closest(\".problemindexholder\").find(\".testCaseMarker_\" + end).hide();\r\n }\r\n }\r\n });\r\n });\r\n\r\n });\r\n</script>\r\n\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 05:38:33</span> (j3).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/73366/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/73366/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/73366/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/73366/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-73366.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'8122c4c4a95216a7',t:'MTY5NjY0NjMxMy43NzAwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"},"long_tags":{"kind":"string","value":"[\"Mathematics including integration, differential equations, etc\"]"},"short_tags":{"kind":"string","value":"[\"math\", \"*2700\"]"},"tutorial_link":{"kind":"string","value":"https://codeforces.com/blog/entry/10629"},"tutorial_page":{"kind":"string","value":"\r\n\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"74361418aed3add319d25ce966ceafdf\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"h1\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Codeforces Round #228 — Editorial - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n \n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Codeforces Round #228 — Editorial - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/81027/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/81027/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/81027/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/81027/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/81027/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/81027/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/81027/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/81027/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/81027/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/81027/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/81027/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/81027/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/81027/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/81027/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/573cedc6b04c15481941f418269f4057/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='74361418aed3add319d25ce966ceafdf'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/81027/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fblog%2Fentry%2F10629\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='74361418aed3add319d25ce966ceafdf'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Pay attention\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n <div style=\"text-align:center;border-bottom: 1px solid rgb(185, 185, 185);margin:0 -0.5em 0.5em -0.5em;padding: 0 1em 0.5em 1em;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 1, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:51:54</span><br/><a href=\"/contestRegistration/1876\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n <div style=\"text-align:center;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 2, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:51:54</span><br/><a href=\"/contestRegistration/1877\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='74361418aed3add319d25ce966ceafdf'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n </label>\r\n </div>\r\n <div style=\"padding: 0 1em 1em 1em;text-align:right;\">\r\n <input style=\"height:1.65em;padding:0 0.75em;\" type=\"submit\" value=\"Find\"/>\r\n </div>\r\n </form>\r\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".handleBox\").autocomplete(\"/data/handles\", {\r\n delay: 200,\r\n width: 200,\r\n selectFirst: false,\r\n matchContains: true,\r\n minChars: 3\r\n });\r\n $(\".handleForm\").attr(\"autocomplete\", \"off\").submit(function () {\r\n var link = \"/profile/userHandle\".replace(\r\n \"userHandle\", $(this).find(\".handleBox\").val()\r\n );\r\n window.location = link;\r\n return false;\r\n });\r\n });\n </script>\n\r\n\r\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Recent actions\n <div class=\"top-links\">\n </div>\n </div>\n <div class=\"recent-actions\">\r\n <ul>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/121073\">Meta Hacker Cup 2023 Round 1</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/.Danet\" title=\"Expert .Danet\" class=\"rated-user user-blue\">.Danet</a> →\r\n <a href=\"/blog/entry/121172\">[TLE on pretest1]</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\" class=\"rated-user user-red\">Pyqe</a> →\r\n <a href=\"/blog/entry/121025\">Codeforces Round #902 (Div. 1, Div. 2, based on COMPFEST 15 — Final Round)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pranshu_Pandya\" title=\"Specialist Pranshu_Pandya\" class=\"rated-user user-cyan\">Pranshu_Pandya</a> →\r\n <a href=\"/blog/entry/121171\">An Interesting Tree Problem</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/sszcdjr\" title=\"Master sszcdjr\" class=\"rated-user user-orange\">sszcdjr</a> →\r\n <a href=\"/blog/entry/119859\">Codeforces Round 896 (Div. 1, Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/119880\">It's Happening! Meta Hacker Cup 2023 Schedule</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/DaviddeGea1\" title=\"Expert DaviddeGea1\" class=\"rated-user user-blue\">DaviddeGea1</a> →\r\n <a href=\"/blog/entry/70917\">Number of ways of dividing an array into 2 parts such that sum of each part is > k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bekh\" title=\"Master Bekh\" class=\"rated-user user-orange\">Bekh</a> →\r\n <a href=\"/blog/entry/74245\">Questions and doubts regarding Aliens DP trick</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a> →\r\n <a href=\"/blog/entry/8192\">Codeforces Round #190 — Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/hocky\" title=\"Candidate Master hocky\" class=\"rated-user user-violet\">hocky</a> →\r\n <a href=\"/blog/entry/95323\">FBHC wuining uw Day? Incwease uw stacc size! (ㅅ´ ˘ `)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/liouzhou_101\" title=\"International Master liouzhou_101\" class=\"rated-user user-orange\">liouzhou_101</a> →\r\n <a href=\"/blog/entry/87598\">Editorial of Codeforces Round #700</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/yeon_gist\" title=\"Newbie yeon_gist\" class=\"rated-user user-gray\">yeon_gist</a> →\r\n <a href=\"/blog/entry/121170\">plusMinusPermutation computing error</a>\r\n <img alt=\"Text created or updated\" title=\"Text created or updated\" src=\"//codeforces.org/s/81027/images/icons/x-update-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/altforminuscontribution\" title=\"Newbie altforminuscontribution\" class=\"rated-user user-gray\">altforminuscontribution</a> →\r\n <a href=\"/blog/entry/121162\">My screen get unexpectedly big, what should I do</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/atcoder_official\" title=\"Unrated, atcoder_official\" class=\"rated-user user-black\">atcoder_official</a> →\r\n <a href=\"/blog/entry/121120\">We will hold UNIQUE VISION Programming Contest 2023 Autumn(AtCoder Beginner Contest 323)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/YouStill_DontKnowMeYet\" title=\"Candidate Master YouStill_DontKnowMeYet\" class=\"rated-user user-violet\">YouStill_DontKnowMeYet</a> →\r\n <a href=\"/blog/entry/117659\">[GYM] Al-Baath Collegiate Programming Contest 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/ankancool\" title=\"Expert ankancool\" class=\"rated-user user-blue\">ankancool</a> →\r\n <a href=\"/blog/entry/121136\">Invitation to AstroByte 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/GeZhiyuan\" title=\"Grandmaster GeZhiyuan\" class=\"rated-user user-red\">GeZhiyuan</a> →\r\n <a href=\"/blog/entry/120943\">Codeforces Round 901 (Div. 1, Div. 2) Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a> →\r\n <a href=\"/blog/entry/120772\">PSA: Increase your stack size before the Meta Hacker Cup, here's how</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/dino_merlin\" title=\"Expert dino_merlin\" class=\"rated-user user-blue\">dino_merlin</a> →\r\n <a href=\"/blog/entry/121145\">Intuitive approach for CEOI Kangaroo?</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/icecuber\" title=\"Grandmaster icecuber\" class=\"rated-user user-red\">icecuber</a> →\r\n <a href=\"/blog/entry/70018\">CSES DP section editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bn00b\" title=\"Newbie Bn00b\" class=\"rated-user user-gray\">Bn00b</a> →\r\n <a href=\"/blog/entry/98820\">[FEATURE REQUEST : ATCODER] TOPICS TAGS AND SORTING BY SOLVE COUNT</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a> →\r\n <a href=\"/blog/entry/121163\">AtCoder Regular Contest 166 Announcement</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/windva\" title=\"Grandmaster windva\" class=\"rated-user user-red\">windva</a> →\r\n <a href=\"/blog/entry/120644\">Codeforces Round 899 (Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Misa-Misa\" title=\"Expert Misa-Misa\" class=\"rated-user user-blue\">Misa-Misa</a> →\r\n <a href=\"/blog/entry/121157\">Someone please help me understand this.</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/shivam565\" title=\"Specialist shivam565\" class=\"rated-user user-cyan\">shivam565</a> →\r\n <a href=\"/blog/entry/108348\">Total number of subarrays with sum atmost k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n </ul>\r\n </div>\r\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/recent-actions\">Detailed →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n</div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li><a\r\n href=\"/profile/cgy4ever\">cgy4ever</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/cgy4ever\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/cgy4ever\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/cgy4ever\">Submissions</a></li>\r\n <li><a\r\n href=\"/groups/with/cgy4ever\">Groups</a></li>\r\n <li><a\r\n href=\"/contests/with/cgy4ever\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/cgy4ever\">Problemsetting</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/cgy4ever\" style=\"text-decoration:none;color:black !important;\">cgy4ever's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"10684\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/10629\"> <p>Codeforces Round #228 — Editorial</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a>,\r\n <span class=\"format-humantime\" title=\"Feb/03/2014 22:14\">10 years ago</span>,\r\n \r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p>You can find the editorial and my solutions here: <a href=\"https://github.com/cgy4ever/CF228\">https://github.com/cgy4ever/CF228</a></p><p><a href=\"/contest/389/problem/A\" title=\"Codeforces Round 228 (Div. 2)\">389A - Fox and Number Game</a></p><p>First we know that: in the optimal solution, all number will be equal: otherwise we can pick a and b (a < b) then do b = b — a, it will make the answer better.</p><p>Then we need an observation: after each operation, the GCD (Greatest common divisor) of all number will remain same. It can be proved by this lemma: if g is a divisor of all number of x[], then after the operation, g is still the divisor of these numbers, and vice versa.</p><p>So in the end, all number will become the GCD of x[].</p><p>Another solution that can pass is: While there exist x[i] > x[j], then do x[i] -= x[j]. We can select arbitrary i and j if there exist more than 1 choice.</p><p><a href=\"/contest/389/problem/B\" title=\"Codeforces Round 228 (Div. 2)\">389B - Fox and Cross</a></p><p>Let's define the first # of a shape is the cell contain # that have the lexicographical smallest coordinate. Then the first # of a cross is the top one.</p><p>Then let x be the first # of the given board. (If the board is empty, then we can draw it with zero crosses.) x must be covered by a cross, and x must be the first # of the cross. (You can try 4 other positions, it will cause a lexicographical smaller # in the board than x)</p><p>So we try to cover this x use one cross, if it leads some part of the cross covers a '.', then there will be no solution. If not, we just reduce the number of # in the board by 4, we can do this again and again.</p><p><a href=\"/contest/389/problem/C\" title=\"Codeforces Round 228 (Div. 2)\">389C - Fox and Box Accumulation</a> / <a href=\"/contest/388/problem/A\" title=\"Codeforces Round 228 (Div. 1)\">388A - Fox and Box Accumulation</a></p><p>We need some observation:</p> <ol> <li><p>There exists an optimal solution such that: in any pile, the box on the higher position will have a smaller strength.</p></li> <li><p>Let k be the minimal number of piles, then there exists an optimal solution such that: The height of all piles is n/k or n/k+1 (if n%k=0, then all of them have the height n/k).</p></li> </ol><p>We can prove them by exchange argument: from an optimal solution, swap the boxes in it to make above property holds, and we can ensure it will remain valid while swapping.</p><p>Then for a given k, we can check whether there exist a solution: the i-th (indexed from 0) smallest strength needs to be at least i/k.</p><p>So we can do binary search (or just enumerate, since n is only 100) on k.</p><p><a href=\"/contest/389/problem/D\" title=\"Codeforces Round 228 (Div. 2)\">389D - Fox and Minimal path</a> / <a href=\"/contest/388/problem/B\" title=\"Codeforces Round 228 (Div. 1)\">388B - Fox and Minimal path</a></p><p>First we need to know how to calculate the number of different shortest paths from vertex 1 to vertex 2: it can be done by dp: dp[1] = 1, dp[v] = sum{dp[t] | dist(1,t) = dist(1,v) — 1}, then dp[2] is our answer.</p><p>We need to do dp layer by layer. (first we consider vertexes have distance 1 to node 1, then vertexes have distance 2 to node 1 and so on.) So we can construct the graph layer by layer, and link edges to control the dp value of it.</p><p>My solution is construct the answer by binary express: If k is 19, then we need some vertexes in previous layer such that the dp value is 16, 2 and 1. So we just need a way to construct layer with dp value equals to 2^k.</p><p>In the first layer, it contains one node: 1, it has the dp value 1. In the next layer, we can construct 2 nodes, with dp value equals to 1. (We use [1 1] to denote it). And the next layer is [1 1 2], then [1 1 2 4], [1 1 2 4 8] and so on. So we need about 30 layers such that gets all 2^k where k < 30. It uses about 500 nodes.</p><p><a href=\"/contest/389/problem/E\" title=\"Codeforces Round 228 (Div. 2)\">389E - Fox and Card Game</a> / <a href=\"/contest/388/problem/C\" title=\"Codeforces Round 228 (Div. 1)\">388C - Fox and Card Game</a></p><p>First let's consider the case which all piles have even size. In this case, we can prove: in the optimal play, Ciel will gets all top most half cards of each pile, and Jiro gets the remain cards.</p><p>We can prove by these facts: Ciel have a strategy to ensure she can get this outcome and Jiro also have a strategy to ensure this outcome. (For Jiro this strategy is easy: just pick the card from pile that Ciel have just picked. For Ciel it's a little bit harder.)</p><p>Why we can conclude they are both the optimal strategy? Ciel just can't win more, because if she played with Jiro with above strategy, Jiro will get the bottom half of each pile.</p><p>Then we come back with cases that contain odd size piles. The result is: for odd size pile, Ciel will get the top (s-1)/2 cards and Jiro will get the bottom (s-1)/2 cards. Then what about the middle one? Let's denote S is all such middle cards. Then we define a reduced game: In each turn, they pick one card from S. The optimal play for this game is easy: Ciel gets the max one, and Jiro gets the 2nd largest one, and Ciel gets the 3rd largest one and so on.</p><p>We can prove Ciel have a strategy to get: all top half parts + cards she will get in the optimal play in the reduced game. And Jiro also have a strategy to get: all bottom half parts + cards he will get in the optimal play in the reduced game. And these strategy are optimal.</p><p><a href=\"/contest/388/problem/D\" title=\"Codeforces Round 228 (Div. 1)\">388D - Fox and Perfect Sets</a></p><p>A perfect set correspond to a linear space, so we can use base to represent it. We do the Gauss–Jordan elimination of vectors in that set, and can get an unique base. (Note that we need to to the all process of Gauss–Jordan elimination, including the elimination after it reached upper triangular)</p><p>And we can construct the bases bit by bit from higher bit to lower, for a bit:</p> <ol> <li><p>We can add a vector to the base such that the bit is the highest bit of that vector. And at this time, all other vector will have 0 in this bit.</p></li> <li><p>Otherwise we need to assign this bit of each vector already in the base. If now we have k vector, then we have 2^k choices.</p></li> </ol><p>And when we do this, we need to know what's the maximal vector in this space. It's not hard:</p> <ol> <li><p>If we add a vector, then in the maximal vector, this bit will be 1.</p></li> <li><p>Otherwise, if we don't have any vector in base yet, then this bit will be 0. Otherwise there will be 2^(k-1) choices results in this bit of maximal vector will be 0, and 2^(k-1) choices results in 1.</p></li> </ol><p>So we can solve this task by DP bit by bit.</p><p><a href=\"/contest/388/problem/E\" title=\"Codeforces Round 228 (Div. 1)\">388E - Fox and Meteor Shower</a></p><p>All tasks beside this are very easy to code. And this one focus on implementation.</p><p>We can represent the orbit of each meteor by a line in 3D space. (we use an axis to represent the time, and two axis to represent the position on the plane.)</p><p>Then the problem becomes: we have some lines in 3D space (they are not complete coincide), find a largest clique such that each pair of lines touch at some point.</p><p>We need this observation: If there are 3 lines in the optimal clique, and these 3 lines are not share a common point, then all line in this clique will on a plane.</p><p>By using this observation, we only need to consider 2 cases:</p> <ol> <li><p>All lines in the clique have a common point.</p></li> <li><p>All lines in the clique are on the same plane.</p></li> </ol><p>Both are easy tasks in theory, but it needs some coding.</p><p>There are two ways:</p> <ol> <li><p>Use integer anywhere. Note that the coordinates of intersection can be rational number, but can't be irrational, so we could do this. We can use some way to encode the plane, direction.</p></li> <li><p>Use floating number. To count same number of points, we can sort (x, y, z) by using the following compare function: if (abs(A.x — B.x) > eps){return A.x < B.x} otherwise { if(abs(A.y-B.y)>eps){return A.y < B.y} otherwise return A.z < B.z}.</p></li> </ol></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/388\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 228 (Div. 1)</a> </span>\r\n </div>\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/389\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 228 (Div. 2)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-21-10684\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"21\",\n blogEntryId: \"10629\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-10684\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+45</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-10684\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/cgy4ever\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/cgy4ever\">\n cgy4ever\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Feb/03/2014 22:14\">10 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/10629#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/10629#comments\">\n 44\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"10700\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (39)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159842\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/YaleZ\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/24526/avatar/5b17db1affad55a5.jpg'/> </a>\n <div><a href=\"/profile/YaleZ\" title=\"Expert YaleZ\" class=\"rated-user user-blue\">YaleZ</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2014 22:38\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159842\" href=\"?#comment-159842\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"159842\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"159842\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"24526\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159842\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thank for timely editorial. I think Markdown is better when publish something on Github. Isn't it?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159842 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159842 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159842\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159846\" commentParentId=\"159842\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/cgy4ever\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2014 22:43\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159846\" href=\"?#comment-159846\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159842\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159846\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"11\"\r\n data-commentUserId=\"62\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+11</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159846\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Yes, I'm working on it. :)</p><p>The website seems to be not stable at this time. So I post them in other sites to ensure all people can see it.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159846 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159846 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159846\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159857\" commentParentId=\"159846\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Nodir.Daminov\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/71439/avatar/d6d2016f6dfe5ecd.jpg'/> </a>\n <div><a href=\"/profile/Nodir.Daminov\" title=\"Candidate Master Nodir.Daminov\" class=\"rated-user user-violet\">Nodir.Daminov</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2014 22:58\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159857\" href=\"?#comment-159857\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159846\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159857\" class=\"CommentVoteFrame\"\r\n class=\"too-negative-comment-vote\"\r\n data-commentRating=\"-35\"\r\n data-commentUserId=\"71439\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-35</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159857\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Maaan is it so hard to COPY ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159857 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159857 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159857\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159874\" commentParentId=\"159857\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/cgy4ever\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2014 23:19\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159874\" href=\"?#comment-159874\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159857\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159874\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"12\"\r\n data-commentUserId=\"62\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+12</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159874\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Sorry for the delay.</p><p>When I was submitting my post that contains the editorial, it always returns "Codeforces is now unavailable." so I just can't post it.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159874 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159874 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159874\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159859\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/BishalG\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/60637/avatar/d21ddf49bbd1630c.jpg'/> </a>\n <div><a href=\"/profile/BishalG\" title=\"Expert BishalG\" class=\"rated-user user-blue\">BishalG</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2014 22:58\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159859\" href=\"?#comment-159859\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159859\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"60637\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159859\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Nice problemSets @<a class=\"rated-user user-orange\" href=\"/profile/cgy4ever\" title=\"International Master cgy4ever\">cgy4ever</a> , although I misunderstood the problem-B <a href=\"/contest/389/problem/B\" title=\"Codeforces Round 228 (Div. 2)\">389B - Fox and Cross</a> upto 1 hrs :( </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159859 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159859 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159859\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159867\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Mr.ink\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Mr.ink\" title=\"Expert Mr.ink\" class=\"rated-user user-blue\">Mr.ink</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2014 23:07\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159867\" href=\"?#comment-159867\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159867\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"128876\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159867\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>due to my slow internet speed i can not see your editorial on github because my country internet has problem with https! </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159867 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159867 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159867\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159881\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Mr.ink\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Mr.ink\" title=\"Expert Mr.ink\" class=\"rated-user user-blue\">Mr.ink</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2014 23:38\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159881\" href=\"?#comment-159881\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159881\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"128876\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159881\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>does anyone have a better solution for div2 C problem?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159881 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159881 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159881\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159883\" commentParentId=\"159881\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/t_thirupathi\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/146179/avatar/98c28348196ce4ca.jpg'/> </a>\n <div><a href=\"/profile/t_thirupathi\" title=\"Specialist t_thirupathi\" class=\"rated-user user-cyan\">t_thirupathi</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2014 23:42\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159883\" href=\"?#comment-159883\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159881\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159883\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"146179\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159883\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Have a look at mine <a href=\"/contest/389/submission/5878414\" title=\"Submission 5878414 by t_thirupathi\">5878414</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159883 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159883 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159883\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159909\" commentParentId=\"159883\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/9charles\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/119814/avatar/653156a3153bc2dd.jpg'/> </a>\n <div><a href=\"/profile/9charles\" title=\"Expert 9charles\" class=\"rated-user user-blue\">9charles</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 06:46\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159909\" href=\"?#comment-159909\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159883\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159909\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"119814\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159909\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can you explain it?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159909 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159909 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159909\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159907\" commentParentId=\"159881\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/k790alex\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/119882/avatar/4baeddca65b2b958.jpg'/> </a>\n <div><a href=\"/profile/k790alex\" title=\"Specialist k790alex\" class=\"rated-user user-cyan\">k790alex</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 06:28\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159907\" href=\"?#comment-159907\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159881\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159907\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"119882\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159907\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I don't know if this is a better way but I didt in the contest.</p><p>Start making a pile with the low strength and while possible, look for a box that can support at least 1 box, then at least 2 boxes, 3, etc, repeat it while you have boxes.</p><p>My solution: <a href=\"/contest/389/submission/5879464\" title=\"Submission 5879464 by k790alex\">5879464</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159907 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159907 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159907\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159914\" commentParentId=\"159907\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/YaleZ\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/24526/avatar/5b17db1affad55a5.jpg'/> </a>\n <div><a href=\"/profile/YaleZ\" title=\"Expert YaleZ\" class=\"rated-user user-blue\">YaleZ</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 07:38\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159914\" href=\"?#comment-159914\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159907\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159914\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"24526\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159914\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Greedy is also a nice solution.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159914 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159914 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159914\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159932\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/worfzyq\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/157364/avatar/8f104a361ed91be8.jpg'/> </a>\n <div><a href=\"/profile/worfzyq\" title=\"Expert worfzyq\" class=\"rated-user user-blue\">worfzyq</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 09:52\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159932\" href=\"?#comment-159932\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159932\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"157364\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159932\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>388C — Fox and Card Game This problem is good magic</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159932 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159932 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159932\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159935\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/orchidmajumder\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/63603/avatar/f8db3747466a7168.jpg'/> </a>\n <div><a href=\"/profile/orchidmajumder\" title=\"Specialist orchidmajumder\" class=\"rated-user user-cyan\">orchidmajumder</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 10:07\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159935\" href=\"?#comment-159935\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"159935\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"159935\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"7\"\r\n data-commentUserId=\"63603\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+7</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159935\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>hii everyone,in Div II E,I can't understand why the optimal play for JIRO is to take the bottom most card from the same pile from where CIEL is picking?should not it try to pick the maximum value among all bottom most card at it's every move??</p><p>Please someone explain why the strategy presented in the editorial is optimal.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159935 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159935 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159935\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159948\" commentParentId=\"159935\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Zzyzx\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/86049/avatar/c698ee674460e7eb.jpg'/> </a>\n <div><a href=\"/profile/Zzyzx\" title=\"Expert Zzyzx\" class=\"rated-user user-blue\">Zzyzx</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 13:07\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159948\" href=\"?#comment-159948\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159935\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159948\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"86049\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159948\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Ok, I'm afraid I do not have a rigorous proof for this. I'll just explain to you why I think it is right.</p><p>First of all, we need to understand that both Ciel and Jiro are smart. Now, whenever it is Ciel's turn, he will pick the "best pile" and try to take everything from that pile and then move on to the next "best pile". Jiro knows that his friend Ciel is smart, so he will try to stop him from taking everything. This can be done only if he picks from the same pile that Ciel does.</p><p>But your question is — what if there is a different pile whose bottom-most card is much better than the bottom-most card of the pile from which Ciel is picking right?</p><p>My answer to this is that, this situation will never arise. Because if there is such a pile, then Ciel will try to take that card in the first place and therefore, Ciel will be picking from the same pile that Jiro will want to pick from.</p><p>Am I making sense? Or is there a flaw in my argument?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159948 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159948 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159948\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159952\" commentParentId=\"159948\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/orchidmajumder\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/63603/avatar/f8db3747466a7168.jpg'/> </a>\n <div><a href=\"/profile/orchidmajumder\" title=\"Specialist orchidmajumder\" class=\"rated-user user-cyan\">orchidmajumder</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 13:32\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159952\" href=\"?#comment-159952\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159948\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159952\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"63603\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159952\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Yes I'm also thinking along the same line.Both are playing optimally and if Ciel is chosing any pile then jiro knows that this pile has better cards in the botttom half.So he won't choose ciel to take the advantage and vice versa.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159952 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159952 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159952\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159944\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hzyfr\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/hzyfr\" title=\"Expert hzyfr\" class=\"rated-user user-blue\">hzyfr</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 12:27\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159944\" href=\"?#comment-159944\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159944\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"129936\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159944\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I have a different idea on D div1 <a href=\"/contest/388/problem/D\" title=\"Codeforces Round 228 (Div. 1)\">388D - Fox and Perfect Sets</a> but I failed on getting some relations in one step.</p><p>Let <em>M</em> be the maximum element in set <em>S</em> . Then if <em>S</em> is a perfect set, its elements should have all bits equals <em>0</em> on positions in <em>M's</em> binary representation(otherwise there must exist another element bigger than <em>M</em>). So let <em>cnt</em> = (number of 1's in binary repersentation of <em>M</em>), then the number of perfect sets which has <em>M</em> as its greatest element is determined by <em>cnt</em> . Well, this is the step I can't come up with a solution(actually the target is to find the number of perfect sets which has <code>2^cnt-1</code> as its greatest element).</p><p>Then the last step is simple. We can apply something like doubling algorithm on the problem.</p><p>We are asked to find the number of perfect sets with all the elements not greater than <em>N</em> . Let's suppose <em>N+1</em> is a power of 2 then its easy to calculate how many numbers not greater than <em>N</em> has <em>cnt</em> = 1,2,...m where m is the length of <em>N</em> in binary representation. That's just simple combinatoric number <em>C(n,i) (1<=i<=n)</em> . And if we have done the previous step, it's easy to get the result.</p><p>Then think about common cases of <em>N</em> . Let's take the highest bit of N and since all above bits are determined, the number of 1's will just add a constant value. So calculate this part and subtract that highest bit of <em>N</em> and do the same thing on remaining value of <em>N</em> , until <em>N=0</em> . At that time we will get the correct answer. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159944 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159944 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159944\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159945\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/rexdf\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/23738/avatar/797fa665fbe1ca78.jpg'/> </a>\n <div><a href=\"/profile/rexdf\" title=\"Specialist rexdf\" class=\"rated-user user-cyan\">rexdf</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 12:36\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159945\" href=\"?#comment-159945\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159945\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"23738\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159945\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>dp[1] = 1, dp[v] = sum{dp[t] | dist(1,t) = dist(1,v) — 1}, then dp[2] is our answer. What's v means? what's '|' means? What's dp[v] means?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159945 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159945 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159945\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159949\" commentParentId=\"159945\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/sancho\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/85894/avatar/e31a4b24327c1000.jpg'/> </a>\n <div><a href=\"/profile/sancho\" title=\"Candidate Master sancho\" class=\"rated-user user-violet\">sancho</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 13:10\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159949\" href=\"?#comment-159949\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159945\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159949\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"85894\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159949\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>v — vertex, answer for which we are getting at this moment, | — means "such as", dp[v] — number of ways from 1 vertex to this one</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159949 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159949 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159949\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159947\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lol12\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/lol12\" title=\"Specialist lol12\" class=\"rated-user user-cyan\">lol12</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 13:04\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159947\" href=\"?#comment-159947\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159947\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"10\"\r\n data-commentUserId=\"152356\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+10</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159947\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can someone please explain solution of Div2-D. Thanx</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159947 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159947 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159947\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"160020\" commentParentId=\"159947\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/YaleZ\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/24526/avatar/5b17db1affad55a5.jpg'/> </a>\n <div><a href=\"/profile/YaleZ\" title=\"Expert YaleZ\" class=\"rated-user user-blue\">YaleZ</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/05/2014 07:07\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-160020\" href=\"?#comment-160020\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159947\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"160020\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"9\"\r\n data-commentUserId=\"24526\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+9</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-160020\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>You can think about binnary. Such as (13)10=(1101)2=((1+(2+0)*2)+1)*2+1</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-160020 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-160020 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-160020\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"469976\" commentParentId=\"159947\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/roll_no_1\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/631859/avatar/36d157f91f64fe7f.jpg'/> </a>\n <div><a href=\"/profile/roll_no_1\" title=\"Master roll_no_1\" class=\"rated-user user-orange\">roll_no_1</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Nov/09/2018 17:27\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-469976\" href=\"?#comment-469976\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159947\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"469976\" revisionCount=\"4\" revision=\"4\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">4</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"469976\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"631859\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-469976\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Here's my implementation of the editorialist's explanation of Div-2 D / Div-1 B: <a href=\"/contest/388/submission/45480077\" title=\"Submission 45480077 by roll_no_1\">45480077</a>. I implemented the layers as [1], [1, 1], [2, 1, 1], [4, 2, 1, 1] and so on.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-469976 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-469976 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-469976\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159967\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/BENYAM1N\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/84938/avatar/d2ae2657d8898e38.jpg'/> </a>\n <div><a href=\"/profile/BENYAM1N\" title=\"Master BENYAM1N\" class=\"rated-user user-orange\">BENYAM1N</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 15:51\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159967\" href=\"?#comment-159967\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159967\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"13\"\r\n data-commentUserId=\"84938\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+13</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159967\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Very good contest and nice editorial. Hope from now on I see more contests from you.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159967 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159967 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159967\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159984\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/kojak_\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/57722/avatar/38990eea59bc188e.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/kojak_\" title=\"Newbie kojak_\" class=\"rated-user user-gray\">kojak_</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 18:34\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159984\" href=\"?#comment-159984\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159984\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"57722\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159984\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Did anyone come up with a DP solution for Div.2 C/ Div.1 A?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159984 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159984 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159984\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"160012\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/IgorKoval\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/51322/avatar/afc854fff49f072a.jpg'/> </a>\n <div><a href=\"/profile/IgorKoval\" title=\"Candidate Master IgorKoval\" class=\"rated-user user-violet\">IgorKoval</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 23:17\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-160012\" href=\"?#comment-160012\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"160012\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"11\"\r\n data-commentUserId=\"51322\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+11</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-160012\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Объясните, пожалуйста, разбор задачи "388D — Fox and Perfect Sets" на пальцах. Как-нибудь без Гаусса и базисов. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-160012 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-160012 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-160012\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"160016\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Mr.ink\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Mr.ink\" title=\"Expert Mr.ink\" class=\"rated-user user-blue\">Mr.ink</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/05/2014 01:08\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-160016\" href=\"?#comment-160016\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"160016\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"128876\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-160016\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>fox and card games is a great problem.thanks!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-160016 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-160016 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-160016\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"160037\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/yaswanth\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/yaswanth\" title=\"Specialist yaswanth\" class=\"rated-user user-cyan\">yaswanth</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/05/2014 18:38\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-160037\" href=\"?#comment-160037\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"160037\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"9\"\r\n data-commentUserId=\"96196\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+9</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-160037\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can anyone explain div2 C question? I did not understand the editorial.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-160037 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-160037 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-160037\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"160063\" commentParentId=\"160037\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/YaleZ\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/24526/avatar/5b17db1affad55a5.jpg'/> </a>\n <div><a href=\"/profile/YaleZ\" title=\"Expert YaleZ\" class=\"rated-user user-blue\">YaleZ</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/06/2014 05:46\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-160063\" href=\"?#comment-160063\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-160037\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"160063\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"24526\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-160063\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>s[i]>=i/k -> k*s[i]>=i There are i boxes' strength smaller than i-th box. So we need to check if the boxes before i-th can be held.</p><p>(I don't know whether I have understood correctly...)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-160063 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-160063 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-160063\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"160053\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/yada\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/142663/avatar/49901b54d1c5f019.jpg'/> </a>\n <div><a href=\"/profile/yada\" title=\"Candidate Master yada\" class=\"rated-user user-violet\">yada</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/05/2014 23:24\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-160053\" href=\"?#comment-160053\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"160053\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"142663\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-160053\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Great Problem! I really enjoy it.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-160053 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-160053 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-160053\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"364019\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lnzva\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/305672/avatar/cf6c09a214141751.jpg'/> </a>\n <div><a href=\"/profile/lnzva\" title=\"Expert lnzva\" class=\"rated-user user-blue\">lnzva</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/02/2017 22:06\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-364019\" href=\"?#comment-364019\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"364019\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"364019\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"305672\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-364019\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In 388C, I'm having a hard time understanding why Jiro's optimal strategy would be to pick the pile Ciel just picked. Why not pick a pile which has a better bottom part than the one Ciel is picking? According to some comments, Ciel would then pick from the second pile-what if another pile has a much better top part? Could someone please help? I saw this problem first 6 months ago, and I had a hard time understanding why this greedy is correct; I saw this problem again today and am having trouble with it again, with no progress.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-364019 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-364019 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-364019\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"647866\" commentParentId=\"364019\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/_wzx27\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1458283/avatar/7d77b62012ae2398.jpg'/> </a>\n <div><a href=\"/profile/_wzx27\" title=\"Candidate Master _wzx27\" class=\"rated-user user-violet\">_wzx27</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/22/2020 18:33\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-647866\" href=\"?#comment-647866\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-364019\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"647866\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1458283\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-647866\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Let's consider such a two-piles situation:</p><p><em>111100</em></p><p><em>001111</em></p><p>is better for Ciel.</p><p>"1" means this card is picked by Ciel,while "0" by Jiro.</p><p>We know that better for Ciel means worse for Jiro.</p><p>So if</p><p><em>111100</em></p><p><em>001111</em></p><p>is better than</p><p><em>111000</em></p><p><em>000111</em></p><p>for Ciel.</p><p>Then when Ciel picked the <strong>first three cards</strong> from <strong>pile 1</strong>,Jiro can just pick the <strong>last three cards</strong> from <strong>pile 1</strong> and finally lead to the result:</p><p><em>111000</em></p><p><em>000111</em></p><p>which is not better for Ciel.</p><p>Generally, if the final result is not balance(half from top and half from bottom) while balance is better than such result for Jiro, Jiro has the ability to adjust it to be balance.So do Ciel.</p><p>Therefore,it reaches balance.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-647866 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-647866 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-647866\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"407776\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/madhur4127\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/568692/avatar/c7d62cc23c758819.jpg'/> </a>\n <div><a href=\"/profile/madhur4127\" title=\"Specialist madhur4127\" class=\"rated-user user-cyan\">madhur4127</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/15/2018 13:06\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-407776\" href=\"?#comment-407776\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"407776\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"568692\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-407776\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>@<a class=\"rated-user user-red\" href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\">cgy4ever</a>, github link shows 404 error(Page not found). Kindly fix it.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-407776 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-407776 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-407776\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"416354\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/introverted\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/657339/avatar/7a6edb1ecc1d3e09.jpg'/> </a>\n <div><a href=\"/profile/introverted\" title=\"Expert introverted\" class=\"rated-user user-blue\">introverted</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/23/2018 11:48\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-416354\" href=\"?#comment-416354\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"416354\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"657339\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-416354\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I solved the DIV1B problem with simple recursion and Divide and Conquer.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-416354 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-416354 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-416354\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"427890\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Nuu\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/652228/avatar/d59867d6477379dc.jpg'/> </a>\n <div><a href=\"/profile/Nuu\" title=\"Candidate Master Nuu\" class=\"rated-user user-violet\">Nuu</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/01/2018 22:33\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-427890\" href=\"?#comment-427890\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"427890\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"652228\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-427890\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can anyone give me some examples of the similar problems to DivC?? I think this problem is very nice for train brain xD</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-427890 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-427890 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-427890\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"629609\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/The_Alchemist\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1275181/avatar/662970aa05d3dfc5.jpg'/> </a>\n <div><a href=\"/profile/The_Alchemist\" title=\"Expert The_Alchemist\" class=\"rated-user user-blue\">The_Alchemist</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/25/2020 21:47\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-629609\" href=\"?#comment-629609\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"629609\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1275181\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-629609\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I know I am very late but can someone pls explain to me div 2C/div1A. Thanks in advance... </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-629609 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-629609 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-629609\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"641010\" commentParentId=\"629609\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/kstheking\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1160931/avatar/e144fc7b0fdb90b1.jpg'/> </a>\n <div><a href=\"/profile/kstheking\" title=\"Pupil kstheking\" class=\"rated-user user-green\">kstheking</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/13/2020 14:47\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-641010\" href=\"?#comment-641010\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-629609\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"641010\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1160931\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-641010\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p><a href=\"https://codeforces.com/contest/388/submission/83605110\">https://codeforces.com/contest/388/submission/83605110</a> Here you go, if you don't get it feel free to ask</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-641010 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-641010 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-641010\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"644488\" commentParentId=\"641010\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/tanisha_\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/tanisha_\" title=\"Newbie tanisha_\" class=\"rated-user user-gray\">tanisha_</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/18/2020 15:26\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-644488\" href=\"?#comment-644488\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-641010\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"644488\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1500127\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-644488\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>is this any algorithm</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-644488 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-644488 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-644488\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"647627\" commentParentId=\"644488\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/kstheking\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1160931/avatar/e144fc7b0fdb90b1.jpg'/> </a>\n <div><a href=\"/profile/kstheking\" title=\"Pupil kstheking\" class=\"rated-user user-green\">kstheking</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/22/2020 08:40\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-647627\" href=\"?#comment-647627\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-644488\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"647627\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"647627\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1160931\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-647627\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Well you can call it a greedy algorithm, when we try to apply greedy by placing the heaviest block in bottom, a little problem occurs because of blocks of same strength for example in case of 10 2 2 1 1 0 0<br />If you try to apply greedy by choosing the strongest block<br />10 2 2 1<br />1 0<br />0<br />= 3 heaps<br />Which is wrong answer as sometimes we lose opportunity to create lesser heaps, as in this case if we use the second 2 to make another heap we can do better<br />10 2 1 0<br />2 1 0<br />= 2 heaps<br />So I apply greedy in the reverse direction by picking the smallest strength brick and placing below it the next smallest brick, this way the optimal number of heaps will be formed as in above example<br />choose 0, then you need >= 1, choose 1, then you need >= 2, choose 2, then you need >= 3 choose 10<br />repeat until you have chosen all the bricks<br />If you don't get anything, feel free to ask :) </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-647627 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-647627 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-647627\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"702677\" commentParentId=\"647627\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/breddreamer\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/853067/avatar/240684624b57996.jpg'/> </a>\n <div><a href=\"/profile/breddreamer\" title=\"Newbie breddreamer\" class=\"rated-user user-gray\">breddreamer</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/27/2020 13:01\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-702677\" href=\"?#comment-702677\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-647627\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"702677\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"853067\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-702677\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks, It helped me to understand your solution idea. And finally, I solved this one.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-702677 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-702677 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-702677\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"649225\" commentParentId=\"641010\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/The_Alchemist\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1275181/avatar/662970aa05d3dfc5.jpg'/> </a>\n <div><a href=\"/profile/The_Alchemist\" title=\"Expert The_Alchemist\" class=\"rated-user user-blue\">The_Alchemist</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/24/2020 12:04\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-649225\" href=\"?#comment-649225\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-641010\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"649225\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1275181\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-649225\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>thank you.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-649225 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-649225 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-649225\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n <br/>\r\n\r\n<div id=\"editBox-10700\" style=\"width:50em;display:none;\">\r\n <div class=\"previewBody\" style=\"border: 1px solid #d4d4d4; margin-bottom: 0.5em; padding: 0.25em; display:none;\"> </div>\r\n <div style=\"width: 1px\"> </div>\r\n <div class=\"commentLocale\" style=\"position: relative; top: 0.5em;left:4px;display: none;\">\r\n <input type=\"radio\" name=\"locale\" value=\"en\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In English</span>\r\n <input style=\"margin-left:1em\" type=\"radio\" name=\"locale\" value=\"ru\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In Russian</span>\r\n </div>\r\n <textarea data-drafts-id=\"CommentReplyFrame\" class=\"wysiwyg\" name=\"editContent\" rows=\"20\" style=\"width:99%;\"></textarea>\r\n <div class=\"error error__content\"></div>\r\n <div style=\"text-align:center;\">\r\n <input type=\"button\" name=\"preview\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Preview\"/>\r\n <input type=\"button\" name=\"save\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Save\"/>\r\n </div>\r\n</div>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n\r\nvar firstPreview10700 = true;\r\nvar lastPreviewContent10700 = '';\r\n\r\nif (!window.moveCommentRevision) {\r\n moveCommentRevision = function(e, dir) {\r\n var p = e.parent();\r\n var revisionCount = parseInt(p.attr(\"revisionCount\"));\r\n var revision = parseInt(p.attr(\"revision\"));\r\n var next = revision + dir;\r\n var commentId = p.attr(\"commentId\");\r\n if (next >= 1 && next <= revisionCount) {\r\n $.post(\r\n \"/data/comment-data\",\r\n {action: \"revision\", commentId: commentId, revision: next},\r\n function(json) {\r\n if (json.success == \"true\") {\r\n var parentDiv = e;\r\n\r\n while (parentDiv !== null && (parentDiv[0].nodeName.toLowerCase() !== \"td\" || !parentDiv.hasClass(\"right\"))) {\r\n parentDiv = parentDiv.parent();\r\n }\r\n\r\n if (parentDiv === null) {\r\n return;\r\n }\r\n\r\n parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\").html(json.content);\r\n Codeforces.setupSpoilers(parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\"));\r\n p.attr(\"revision\", next);\r\n p.find(\"span.revision\").text(next);\r\n if (next == 1) {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"visible\");\r\n }\r\n if (next == revisionCount) {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"visible\");\r\n }\r\n\r\n window.updateTypography();\r\n MathJax.Hub.Typeset();\r\n } else {\r\n alert(e.error);\r\n }\r\n },\r\n \"json\"\r\n );\r\n }\r\n };\r\n}\r\n\r\n$(\"div[commentableId=10700] a.leftRevision\").click(function () {\r\n window.moveCommentRevision($(this), -1);\r\n return false;\r\n});\r\n\r\n$(\"div[commentableId=10700] a.rightRevision\").click(function () {\r\n window.moveCommentRevision($(this), +1);\r\n return false;\r\n});\r\n\r\n\r\n\r\n });\n </script>\n\r\n\r\n <script src=\"//codeforces.org/s/81027/js/swfobject-2.2.min.js\" type=\"text/javascript\"></script>\n <script src=\"//codeforces.org/s/81027/js/ftaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n if (window.evercookie) {\n var ec = new evercookie({\n history: false,\n silverlight: false,\n baseurl: '',\n asseturi: '/assets',\n phpuri: '/2fdcd78',\n pngPath: '/eps',\n etagPath: '/ees',\n cachePath: '/ecs'\n });\n\n var randomNumber = function () {\n return Math.random().toString(36).substr(2);\n };\n\n var randomToken = function () {\n return (randomNumber() + randomNumber()).substring(0, 18);\n };\n\n window._ftaa = \"\";\n\n ec.get(\"70a7c28f3de\", function (value) {\n window._ftaa = value;\n if (!window._ftaa) {\n window._ftaa = randomToken();\n ec.set(\"70a7c28f3de\", window._ftaa);\n }\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n } else {\n window._ftaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\n <script src=\"//codeforces.org/s/81027/js/bfaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n var fpCallback = function() {\n Fingerprint2.get({}, function(components) {\n window._bfaa = Fingerprint2.x64hash128(components.map(function (pair) { return pair.value }).join(), 31);\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n };\n if (typeof Fingerprint2 !== 'undefined') {\n if (window.requestIdleCallback) {\n requestIdleCallback(fpCallback)\n } else {\n setTimeout(fpCallback, 500)\n }\n } else {\n window._bfaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"a.new-root-comment\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n\r\n $(\".comment-table .reply a\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".vote-for-comment\").mouseover(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").mouseout(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").click(function () {\r\n var vote = $(this);\r\n var commentId = $(this).parent().attr(\"commentid\");\r\n var commentRating = $(this).parent().attr(\"data-commentRating\");\r\n var direction = $(this).attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n $.post(\"/data/comment/vote\", {commentId: commentId, _tta: Codeforces.tta(), vote: direction, commentRating: commentRating}, function(data) {\r\n if (direction != 0 && !ownComment && data[\"success\"] == \"true\") {\r\n vote.parent().find(\".vote-for-comment\").attr(\"voteDirection\", 0);\r\n if (direction == 1)\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n else {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.closest(\".CommentVoteFrame\").find(\".ComplaintFrame\").css(\"display\", \"inline-block\");\r\n }\r\n vote.find(\"img\").attr(\"popacity\", \"1.0\");\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n vote.parent().find(\".commentRating\").html(data[\"commentRating\"]);\r\n }\r\n Codeforces.showMessage(data[\"message\"]);\r\n }, \"json\");\r\n return false;\r\n });\r\n\r\n $(\".negative-comment-vote\").closest(\".comment-table\").addClass(\"comment-bad\");\r\n\r\n $(\".troll-comment-vote\").closest(\".comment\").css(\"display\", \"none\");\r\n\r\n $(\".too-negative-comment-vote\").closest(\".comment-table\").each(function () {\r\n var e = $(this);\r\n e.addClass(\"comment-too-bad\");\r\n var commentId = e.attr(\"commentId\");\r\n $(\"<div class='bad-comment-replacement ttypography'>The comment is hidden because of too negative feedback, click <a href=# class=show-bad-comment-link>here</a> to view it</div>\").appendTo(\r\n e.find(\".right\")\r\n );\r\n e.find(\".comment-content\").hide();\r\n e.find(\".show-bad-comment-link\").click(function () {\r\n e.find(\".comment-content\").show();\r\n e.find(\".bad-comment-replacement\").hide();\r\n return false;\r\n });\r\n });\r\n });\n </script>\n </div>\r\n\r\n <style type=\"text/css\">\r\n .new-comments-box {\r\n padding: 0.5em;\r\n width: 22px;\r\n font-size: 1.3rem;\r\n font-weight: bold !important;\r\n\r\n position: fixed;\r\n top: 40%;\r\n right: 0;\r\n opacity: 0.2;\r\n color: white;\r\n text-align: center;\r\n\r\n border: 1px solid #222;\r\n background-color: #888 !important;\r\n border-radius: 3px;\r\n -moz-border-radius: 3px;\r\n -webkit-border-radius: 3px;\r\n }\r\n\r\n .new-comments-box:hover {\r\n opacity: 1;\r\n }\r\n\r\n .new-comments-box .dir:hover {\r\n background: #3B5998 !important;\r\n cursor: pointer;\r\n }\r\n </style>\r\n\r\n <div class=\"new-comments-box\" data-position=\"outside\" data-index=\"-1\" style=\"display: none;\">\r\n <div class=\"up dir\" title=\"Ctrl+Up\">↑<hr/>\r\n </div>\r\n <div class=\"info\" title=\"New comments\"></div>\r\n <div class=\"down dir\" title=\"Ctrl+Down\">\r\n <hr/>↓\r\n </div>\r\n </div>\r\n\r\n <script>\r\n $(\".show-archived-checkbox\").change(function () {\r\n const checked = $(this).is(\":checked\");\r\n $.post(\"/data/comment-data\", {action: \"setShowArchived\", checked}, function (json) {\r\n if (json[\"success\"] !== \"true\") {\r\n alert(json[\"error\"]);\r\n } else {\r\n if (checked) {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are now displayed\")\r\n } else {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are no longer displayed\")\r\n }\r\n }\r\n });\r\n return false;\r\n });\r\n\r\n function gotoComment(direction) {\r\n var box = $(\".new-comments-box\");\r\n var index = parseInt(box.attr(\"data-index\"));\r\n if (index == -1)\r\n index = 0;\r\n else\r\n index = Math.max(0, Math.min(parseInt(box.find(\".info\").text()) - 1, index + direction));\r\n box.attr(\"data-index\", index);\r\n var comment = $($(\".comment .highlight-blue[commentId]\").get(index));\r\n $('html, body').animate({\r\n 'scrollTop': Math.max(0, comment.offset().top - ($(window).height() - comment.height()) / 2)\r\n });\r\n return false;\r\n }\r\n\r\n $(\".new-comments-box .down\").click(function () {\r\n return gotoComment(1);\r\n });\r\n\r\n $(\".new-comments-box .up\").click(function () {\r\n return gotoComment(-1);\r\n });\r\n\r\n $(document).keydown(function (e) {\r\n var code = (e.keyCode ? e.keyCode : e.which);\r\n if (e.ctrlKey) {\r\n if (code == 38 || code == 40) {\r\n gotoComment(code - 39);\r\n }\r\n }\r\n });\r\n\r\n var newCommentCount = $(\".comment .highlight-blue[commentId]\").length;\r\n if (newCommentCount > 0) {\r\n $(\".new-comments-box .info\").text(newCommentCount);\r\n $(\".new-comments-box\").show();\r\n }\r\n\r\n $('table.comment-table').mouseenter(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").addClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n\r\n $('table.comment-table').mouseleave(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").removeClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n </script>\r\n\r\n\r\n\r\n <script>\r\n function adjustTopicComplainFrames() {\r\n let topicIds = [];\r\n\r\n $(\".has-topic-id\").each(function () {\r\n const $this = $(this);\r\n const topicId = $this.attr(\"topicId\");\r\n if (topicId) {\r\n topicIds.push(topicId);\r\n }\r\n });\r\n\r\n $.post(\"/data/topics\", {\r\n action: \"findComplainableTopicIds\",\r\n topicIds: topicIds.join(\",\")\r\n }, function (json) {\r\n if (json[\"success\"] === \"true\") {\r\n for (const topicId of json[\"complainableTopicIds\"].split(\",\")) {\r\n $(\".has-topic-id[topicId=\" + topicId + \"]\").each(function () {\r\n $(this).find(\".meta .ComplaintFrame\").css(\"display\", \"inline-block\");\r\n });\r\n }\r\n }\r\n }, \"json\");\r\n }\r\n\r\n $(function () {\r\n adjustTopicComplainFrames();\r\n })\r\n </script>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-10684\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 10684, _tta: Codeforces.tta(), topicRevisionId: 36670, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-10684\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 10684, _tta: Codeforces.tta(), topicRevisionId: 36670, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n </div>\r\n </div>\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 22:13:07</span> (h1).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/81027/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/81027/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/81027/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/81027/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-81027.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'812875a2ab4016f4',t:'MTY5NjcwNTk4Ny4yMjQwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"}}},{"rowIdx":1962,"cells":{"problem_id":{"kind":"string","value":"388E"},"contest":{"kind":"string","value":"388"},"problem":{"kind":"string","value":"E"},"lang":{"kind":"string","value":"en"},"problem_title":{"kind":"string","value":"E. Fox and Meteor Shower"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">E. Fox and Meteor Shower</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>6 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>There is a meteor shower on the sky and there are <span class=\"tex-span\"><i>n</i></span> meteors. The sky can be viewed as a 2D Euclid Plane and the meteor is point on this plane. </p><p>Fox Ciel looks at the sky. She finds out that the orbit of each meteor is a straight line, and each meteor has a constant velocity. Now Ciel wants to know: what is the maximum number of <span class=\"tex-font-style-bf\">meteors</span> such that any pair met at the same position at a certain time? Note that the time is not limited and can be also negative. The meteors will never collide when they appear at the same position at the same time.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains an integer <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">1 ≤ <i>n</i> ≤ 1000</span>). Each of the next <span class=\"tex-span\"><i>n</i></span> lines contains six integers: <span class=\"tex-span\"><i>t</i><sub class=\"lower-index\">1</sub>, <i>x</i><sub class=\"lower-index\">1</sub>, <i>y</i><sub class=\"lower-index\">1</sub>, <i>t</i><sub class=\"lower-index\">2</sub>, <i>x</i><sub class=\"lower-index\">2</sub>, <i>y</i><sub class=\"lower-index\">2</sub></span> — the description of a meteor's orbit: at time <span class=\"tex-span\"><i>t</i><sub class=\"lower-index\">1</sub></span>, the current meteor is located at the point (<span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">1</sub></span>, <span class=\"tex-span\"><i>y</i><sub class=\"lower-index\">1</sub></span>) and at time <span class=\"tex-span\"><i>t</i><sub class=\"lower-index\">2</sub></span>, the meteor is located at point (<span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">2</sub></span>, <span class=\"tex-span\"><i>y</i><sub class=\"lower-index\">2</sub></span>) (<span class=\"tex-span\"> - 10<sup class=\"upper-index\">6</sup> ≤ <i>t</i><sub class=\"lower-index\">1</sub>, <i>x</i><sub class=\"lower-index\">1</sub>, <i>y</i><sub class=\"lower-index\">1</sub>, <i>t</i><sub class=\"lower-index\">2</sub>, <i>x</i><sub class=\"lower-index\">2</sub>, <i>y</i><sub class=\"lower-index\">2</sub> ≤ 10<sup class=\"upper-index\">6</sup>; <i>t</i><sub class=\"lower-index\">1</sub> ≠ <i>t</i><sub class=\"lower-index\">2</sub></span>). </p><p>There will be no two meteors are always in the same position for any time.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print a single integer — the maximum number of meteors such that any pair met at the same position at a certain time.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>2<br/>0 0 1 1 0 2<br/>0 1 0 1 2 0<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>2<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3<br/>-1 -1 0 3 3 0<br/>0 2 -1 -1 3 -2<br/>-2 0 -1 6 0 3<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>3<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>4<br/>0 0 0 1 0 1<br/>0 0 1 1 1 1<br/>0 1 1 1 1 0<br/>0 1 0 1 0 0<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>1<br/>0 0 0 1 0 0<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1<br/></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>In example 1, meteor 1 and 2 meet in <span class=\"tex-span\"><i>t</i></span>=-1 at (0, 0).</p><center><img class=\"tex-graphics\" src=\"https://espresso.codeforces.com/b6b04048a4c6aae2c0081c2a348c4e9ef92ecf99.png\" style=\"max-width: 100.0%;max-height: 100.0%;\"/></center><p>In example 2, meteor 1 and 2 meet in <span class=\"tex-span\"><i>t</i></span>=1 at (1, 0), meteor 1 and 3 meet in <span class=\"tex-span\"><i>t</i></span>=0 at (0, 0) and meteor 2 and 3 meet in <span class=\"tex-span\"><i>t</i></span>=2 at (0, 1).</p><center><img class=\"tex-graphics\" src=\"https://espresso.codeforces.com/6370084ac08caf5bb738d631c9c69d1ad7225d8d.png\" style=\"max-width: 100.0%;max-height: 100.0%;\"/></center><p>In example 3, no two meteor meet.</p><center><img class=\"tex-graphics\" src=\"https://espresso.codeforces.com/91340729422997e7b92f9275ae5b686ac55d898d.png\" style=\"max-width: 100.0%;max-height: 100.0%;\"/></center><p>In example 4, there is only 1 meteor, and its velocity is zero.</p><center><img class=\"tex-graphics\" src=\"https://espresso.codeforces.com/0394e66e505b8cfb41e946b5addd3365b0ad07ca.png\" style=\"max-width: 100.0%;max-height: 100.0%;\"/></center><p>If your browser doesn't support animation png, please see the gif version here: </p><p>http://assets.codeforces.com/images/388e/example1.gif</p><p>http://assets.codeforces.com/images/388e/example2.gif</p><p>http://assets.codeforces.com/images/388e/example3.gif</p><p>http://assets.codeforces.com/images/388e/example4.gif</p></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"f633a3290fc1c40243df39fa4029e0ca\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - E - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"fe71135886e33994ae4d9b5e4703fc32ee0c7819\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - E - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/73366/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/73366/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/73366/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/73366/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/73366/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/73366/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/73366/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/73366/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/73366/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/73366/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/73366/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/73366/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/73366/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/73366/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/sidebar-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/a037fe51637846d9c7c725713cd840ea/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='f633a3290fc1c40243df39fa4029e0ca'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/73366/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/73366/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fcontest%2F388%2Fproblem%2FE%3Flocale%3Den\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"current\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='f633a3290fc1c40243df39fa4029e0ca'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:100%;\"><a style=\"color: black\" href=\"/contest/388\">Codeforces Round 228 (Div. 1)</a></th>\n </tr>\n <tr>\n <td class=\"left bottom\" colspan=\"1\"><span class=\"contest-state-phase\">Finished</span></td>\n </tr>\n </tbody>\n </table>\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Practice?\n <div class=\"top-links\">\n </div>\n </div>\n<div>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Want to solve the contest problems after the official contest ends? Just register for practice and you will be able to submit solutions.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"\" method=\"post\"><input type='hidden' name='csrf_token' value='f633a3290fc1c40243df39fa4029e0ca'/>\r\n <input type=\"hidden\" name=\"action\" value=\"registerForPractice\"/>\r\n <input type=\"submit\" name=\"submit\" value=\"Register for practice\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div> \r\n</div>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox ContestVirtualFrame borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Virtual participation <i class=\"sidebar-caption-icon las la-angle-down\"></i>\r\n\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\" \"\r\n\r\n data-page-url=\"/data/sidebarFrames\"\r\n\r\n>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests.\n\nIf you've seen these problems, a virtual contest is not for you - solve these problems in the archive.\n\nIf you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.\n\nNever use someone else's code, read the tutorials or communicate with other person during a virtual contest.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"/contest/388/virtual\" method=\"get\">\r\n <input type=\"submit\" name=\"submit\" value=\"Start virtual contest\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div>\r\n</div>\r\n <script>\r\n $(function () {\r\n $(\".ContestVirtualFrame .sidebar-caption-icon\").click(function() {\r\n $(this).toggleClass(\"la-angle-down la-angle-right\");\r\n const $target = $(this).parent().next();\r\n $target.toggle();\r\n const dataPageUrl = $target.attr(\"data-page-url\");\r\n const collapsed = $(this).hasClass(\"la-angle-right\");\r\n const params = {\r\n action: \"setCollapsed\",\r\n sidebarFrameSimpleClassName: \"ContestVirtualFrame\",\r\n collapsed\r\n };\r\n $.each($target[0].attributes, function(i, a) {\r\n const name = a.name;\r\n if (name.startsWith(\"data-extra-key-\")) {\r\n const key = a.value;\r\n const keyIndex = parseInt(name.substring(\"data-extra-key-\".length));\r\n const value = $target.attr(\"data-extra-value-\" + keyIndex);\r\n params[key] = value;\r\n }\r\n });\r\n $.post(dataPageUrl, params, function (result) {\r\n if (result[\"success\"] !== \"true\") {\r\n Codeforces.showMessage(\"Failed to save collapsed state.\");\r\n }\r\n }, \"json\");\r\n return false;\r\n });\r\n })\r\n </script>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Problem tags\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Geometry, computational geometry\">\r\n geometry\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Difficulty\">\r\n *3100\r\n</span>\r\n </div>\n <div style=\"clear:both;text-align:right;font-size:1.1rem;\">\r\n <span title=\"Please login into the Codeforces\" class=\"notice\">No tag edit access</span>\r\n </div>\r\n</div>\r\n </div>\n\r\n<form id=\"addTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='f633a3290fc1c40243df39fa4029e0ca'/>\r\n <input name=\"action\" type=\"hidden\" value=\"addTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"6409\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<form id=\"removeTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='f633a3290fc1c40243df39fa4029e0ca'/>\r\n <input name=\"action\" type=\"hidden\" value=\"removeTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"6409\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<script type=\"text/javascript\">\r\n $(\".tag-box img\").click(function () {\r\n var tagName = $(this).attr(\"value\");\r\n Codeforces.confirm(\"Are you sure you want to remove this tag?\", function () {\r\n $(\"#removeTagForm input[name=tagName]\").val(tagName);\r\n $(\"#removeTagForm\").submit();\r\n }, function () {\r\n }, \"Yes\", \"No\");\r\n });\r\n\r\n $(\"#addTagLink\").click(function () {\r\n $(this).hide();\r\n $(\"#addTagLabel\").show();\r\n return false;\r\n });\r\n\r\n $(\"#addTagSelect\").change(function () {\r\n var tagName = $(this).val();\r\n if (tagName === \"\") {\r\n $(\"#addTagLabel\").hide();\r\n $(\"#addTagLink\").show();\r\n } else {\r\n $(\"#addTagForm input[name=tagName]\").val(tagName);\r\n $(\"#addTagForm\").submit();\r\n }\r\n });\r\n</script>\r\n\r\n<style type=\"text/css\">\r\n#new-resource-form tr td {\r\npadding-top: 0.5em;\r\n}\r\n#new-resource-form input:not([type=\"submit\"]) {\r\nfont-size: 0.8em;\r\n}\r\n#new-resource-form select {\r\nfont-size: 0.8em;\r\n}\r\n.new-resource-error {\r\nfont-size: 0.8em;\r\n}\r\n.resource-locale {\r\ncolor: #666;\r\nfont-family: Consolas, \"Andale Mono WT\", \"Andale Mono\", \"Lucida Console\", \"Lucida Sans Typewriter\", \"DejaVu Sans Mono\", \"Bitstream Vera Sans Mono\", \"Liberation Mono\", \"Nimbus Mono L\", Monaco, \"Courier New\", Courier, monospace;\r\n}\r\n</style>\r\n<div class=\"roundbox sidebox sidebar-menu borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Contest materials\n<div class=\"top-links\">\n</div>\n</div>\n<ul>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/10605\" title=\"Codeforces Round #228\" target=\"_blank\">Codeforces Round #228</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"2187:2188\" resourceName=\"Announcement\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/10629\" title=\"Codeforces Round #228 — Editorial\" target=\"_blank\">Tutorial <span class=\"resource-locale\">(en)</span></a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"2192\" resourceName=\"Codeforces Round #228 — Editorial\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n</ul>\r\n</div></div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li class=\"current selectedLava\"><a\r\n href=\"/contest/388\">Problems</a></li>\r\n <li><a\r\n href=\"/contest/388/submit\">Submit Code</a></li>\r\n <li><a\r\n href=\"/contest/388/my\">My Submissions</a></li>\r\n <li><a\r\n href=\"/contest/388/status\">Status</a></li>\r\n <li><a\r\n href=\"/contest/388/hacks\">Hacks</a></li>\r\n <li><a\r\n href=\"/contest/388/room/1\">Room</a></li>\r\n <li><a\r\n href=\"/contest/388/standings\">Standings</a></li>\r\n <li><a\r\n href=\"/contest/388/customtest\">Custom Invocation</a></li>\r\n</ul>\r\n</div>\n\r\n <style>\r\n #facebox .content:has(.diff-popup) {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n }\r\n\r\n .testCaseMarker {\r\n position: absolute;\r\n font-weight: bold;\r\n font-size: 1rem;\r\n }\r\n\r\n .diff-popup {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n display: none;\r\n overflow: auto;\r\n }\r\n\r\n .input-output-copier {\r\n font-size: 1.2rem;\r\n float: right;\r\n color: #888 !important;\r\n cursor: pointer;\r\n border: 1px solid rgb(185, 185, 185);\r\n padding: 3px;\r\n margin: 1px;\r\n line-height: 1.1rem;\r\n text-transform: none;\r\n }\r\n\r\n .input-output-copier:hover {\r\n background-color: #def;\r\n }\r\n\r\n .test-explanation textarea {\r\n width: 100%;\r\n height: 1.5em;\r\n }\r\n\r\n .pending-submission-message {\r\n color: darkorange !important;\r\n }\r\n </style>\r\n <script>\r\n const OPENING_SPACE = String.fromCharCode(1001);\r\n const CLOSING_SPACE = String.fromCharCode(1002);\r\n\r\n const nodeToText = function (node, pre) {\r\n let result = [];\r\n\r\n if (node.tagName === \"SCRIPT\" || node.tagName === \"math\"\r\n || (node.classList && node.classList.contains(\"input-output-copier\")))\r\n return [];\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(OPENING_SPACE);\r\n }\r\n\r\n if (node.nodeType === Node.TEXT_NODE) {\r\n let s = node.textContent;\r\n if (!pre) {\r\n s = s.replace(/\\s+/g, \" \");\r\n }\r\n if (s.length > 0) {\r\n result.push(s);\r\n }\r\n }\r\n\r\n if (pre && node.tagName === \"BR\") {\r\n result.push(\"\\n\");\r\n }\r\n\r\n node.childNodes.forEach(function (child) {\r\n result.push(nodeToText(child, node.tagName === \"PRE\").join(\"\"));\r\n });\r\n\r\n if (node.tagName === \"DIV\"\r\n || node.tagName === \"P\"\r\n || node.tagName === \"PRE\"\r\n || node.tagName === \"UL\"\r\n || node.tagName === \"LI\"\r\n ) {\r\n result.push(\"\\n\");\r\n }\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(CLOSING_SPACE);\r\n }\r\n\r\n return result;\r\n }\r\n\r\n const isSpecial = function (c) {\r\n return c === ',' || c === '.' || c === ';' || c === ')' || c === ' ';\r\n }\r\n\r\n const convertStatementToText = function(statmentNode) {\r\n const text = nodeToText(statmentNode, false).join(\"\").replace(/ +/g, \" \").replace(/\\n\\n+/g, \"\\n\\n\");\r\n let result = [];\r\n for (let i = 0; i < text.length; i++) {\r\n const c = text.charAt(i);\r\n if (c === OPENING_SPACE) {\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"E\" data-uuid=\"ps_78fd70133e7504f998d2f8ba65068d69809e70c6\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">E. Fox and Meteor Shower</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>6 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>There is a meteor shower on the sky and there are <span class=\"tex-span\"><i>n</i></span> meteors. The sky can be viewed as a 2D Euclid Plane and the meteor is point on this plane. </p><p>Fox Ciel looks at the sky. She finds out that the orbit of each meteor is a straight line, and each meteor has a constant velocity. Now Ciel wants to know: what is the maximum number of <span class=\"tex-font-style-bf\">meteors</span> such that any pair met at the same position at a certain time? Note that the time is not limited and can be also negative. The meteors will never collide when they appear at the same position at the same time.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains an integer <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">1 ≤ <i>n</i> ≤ 1000</span>). Each of the next <span class=\"tex-span\"><i>n</i></span> lines contains six integers: <span class=\"tex-span\"><i>t</i><sub class=\"lower-index\">1</sub>, <i>x</i><sub class=\"lower-index\">1</sub>, <i>y</i><sub class=\"lower-index\">1</sub>, <i>t</i><sub class=\"lower-index\">2</sub>, <i>x</i><sub class=\"lower-index\">2</sub>, <i>y</i><sub class=\"lower-index\">2</sub></span> — the description of a meteor's orbit: at time <span class=\"tex-span\"><i>t</i><sub class=\"lower-index\">1</sub></span>, the current meteor is located at the point (<span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">1</sub></span>, <span class=\"tex-span\"><i>y</i><sub class=\"lower-index\">1</sub></span>) and at time <span class=\"tex-span\"><i>t</i><sub class=\"lower-index\">2</sub></span>, the meteor is located at point (<span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">2</sub></span>, <span class=\"tex-span\"><i>y</i><sub class=\"lower-index\">2</sub></span>) (<span class=\"tex-span\"> - 10<sup class=\"upper-index\">6</sup> ≤ <i>t</i><sub class=\"lower-index\">1</sub>, <i>x</i><sub class=\"lower-index\">1</sub>, <i>y</i><sub class=\"lower-index\">1</sub>, <i>t</i><sub class=\"lower-index\">2</sub>, <i>x</i><sub class=\"lower-index\">2</sub>, <i>y</i><sub class=\"lower-index\">2</sub> ≤ 10<sup class=\"upper-index\">6</sup>; <i>t</i><sub class=\"lower-index\">1</sub> ≠ <i>t</i><sub class=\"lower-index\">2</sub></span>). </p><p>There will be no two meteors are always in the same position for any time.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print a single integer — the maximum number of meteors such that any pair met at the same position at a certain time.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>2<br />0 0 1 1 0 2<br />0 1 0 1 2 0<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>2<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3<br />-1 -1 0 3 3 0<br />0 2 -1 -1 3 -2<br />-2 0 -1 6 0 3<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>3<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>4<br />0 0 0 1 0 1<br />0 0 1 1 1 1<br />0 1 1 1 1 0<br />0 1 0 1 0 0<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>1<br />0 0 0 1 0 0<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1<br /></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>In example 1, meteor 1 and 2 meet in <span class=\"tex-span\"><i>t</i></span>=-1 at (0, 0).</p><center><img class=\"tex-graphics\" src=\"https://espresso.codeforces.com/b6b04048a4c6aae2c0081c2a348c4e9ef92ecf99.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></center><p>In example 2, meteor 1 and 2 meet in <span class=\"tex-span\"><i>t</i></span>=1 at (1, 0), meteor 1 and 3 meet in <span class=\"tex-span\"><i>t</i></span>=0 at (0, 0) and meteor 2 and 3 meet in <span class=\"tex-span\"><i>t</i></span>=2 at (0, 1).</p><center><img class=\"tex-graphics\" src=\"https://espresso.codeforces.com/6370084ac08caf5bb738d631c9c69d1ad7225d8d.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></center><p>In example 3, no two meteor meet.</p><center><img class=\"tex-graphics\" src=\"https://espresso.codeforces.com/91340729422997e7b92f9275ae5b686ac55d898d.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></center><p>In example 4, there is only 1 meteor, and its velocity is zero.</p><center><img class=\"tex-graphics\" src=\"https://espresso.codeforces.com/0394e66e505b8cfb41e946b5addd3365b0ad07ca.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></center><p>If your browser doesn't support animation png, please see the gif version here: </p><p>http://assets.codeforces.com/images/388e/example1.gif</p><p>http://assets.codeforces.com/images/388e/example2.gif</p><p>http://assets.codeforces.com/images/388e/example3.gif</p><p>http://assets.codeforces.com/images/388e/example4.gif</p></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=E]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== statementText) {\r\n $problem.find(\".diff-notifier\").show();\r\n\r\n $problem.find(\".diff-notifier-close\").click(function() {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n $problem.find(\".diff-notifier\").hide();\r\n });\r\n\r\n $problem.find(\"a.view-changes\").click(function() {\r\n $.post(\"/data/diff\", {action: \"getDiff\", a: previousStatementText, b: statementText}, function (result) {\r\n if (result[\"success\"] === \"true\") {\r\n Codeforces.facebox(\".diff-popup\", \"//codeforces.org/s/73366\");\r\n $(\"#facebox .diff-popup\").html(result[\"diff\"]);\r\n }\r\n }, \"json\");\r\n });\r\n }\r\n } else {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n }\r\n });\r\n });\r\n </script>\r\n\r\n\r\n<script type=\"text/javascript\">\r\n $(document).ready(function () {\r\n window.changedTests = new Set();\r\n\r\n function endsWith(string, suffix) {\r\n return string.indexOf(suffix, string.length - suffix.length) !== -1;\r\n }\r\n\r\n const inputFileDiv = $(\"div.input-file\");\r\n const inputFile = inputFileDiv.text();\r\n const outputFileDiv = $(\"div.output-file\");\r\n const outputFile = outputFileDiv.text();\r\n\r\n\r\n if (!endsWith(inputFile, \"standard input\")\r\n && !endsWith(inputFile, \"standard input\")) {\r\n inputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n if (!endsWith(outputFile, \"standard output\")\r\n && !endsWith(outputFile, \"standard output\")) {\r\n outputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n const titleDiv = $(\"div.header div.title\");\r\n\r\n\r\n\r\n String.prototype.replaceAll = function (search, replace) {\r\n return this.split(search).join(replace);\r\n };\r\n\r\n $(\".sample-test .title\").each(function () {\r\n const preId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n const cpyId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n\r\n $(this).parent().find(\"pre\").attr(\"id\", preId);\r\n const $copy = $(\"<div title='Copy' data-clipboard-target='#\" + preId + \"' id='\" + cpyId + \"' class='input-output-copier'>Copy</div>\");\r\n $(this).append($copy);\r\n\r\n const clipboard = new Clipboard('#' + cpyId, {\r\n text: function (trigger) {\r\n const pre = document.querySelector('#' + preId);\r\n const lines = pre.querySelectorAll(\".test-example-line\");\r\n return Codeforces.filterClipboardText(pre.innerText, lines.length);\r\n }\r\n });\r\n\r\n const isInput = $(this).parent().hasClass(\"input\");\r\n\r\n clipboard.on('success', function (e) {\r\n if (isInput) {\r\n Codeforces.showMessage(\"The example input has been copied into the clipboard\");\r\n } else {\r\n Codeforces.showMessage(\"The example output has been copied into the clipboard\");\r\n }\r\n e.clearSelection();\r\n });\r\n });\r\n\r\n $(\".test-form-item input\").change(function () {\r\n addPendingSubmissionMessage($($(this).closest(\"form\")), \"You changed the answer, do not forget to submit it if you want to save the changes\");\r\n const index = $(this).closest(\".problemindexholder\").attr(\"problemindex\");\r\n let test = \"\";\r\n $(this).closest(\"form input\").each(function () {\r\n const test_ = $(this).attr(\"name\");\r\n if (test_ && test_.substring(0, 4) === \"test\") {\r\n test = test_;\r\n }\r\n });\r\n if (index.length > 0 && test.length > 0) {\r\n const indexTest = index + \"::\" + test;\r\n window.changedTests.add(indexTest);\r\n }\r\n });\r\n\r\n $(window).on('beforeunload', function () {\r\n if (window.changedTests.size > 0) {\r\n return 'Dialog text here';\r\n }\r\n });\r\n\r\n autosize($('.test-explanation textarea'));\r\n\r\n $(\".test-example-line\").hover(function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n let top = 1E20;\r\n let left = 1E20;\r\n let problem = $(this).closest(\".problemindexholder\");\r\n $(this).closest(\".input\").find(\".\" + clazz).css(\"background-color\", \"#FFFDE7\").each(function() {\r\n top = Math.min(top, $(this).offset().top);\r\n left = Math.min(left, $(this).offset().left);\r\n });\r\n let testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n if (testCaseMarker.length === 0) {\r\n const html = \"<div class=\\\"testCaseMarker testCaseMarker_\" + end + \" notice\\\"></div>\";\r\n problem.append($(html));\r\n testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n }\r\n if (testCaseMarker) {\r\n testCaseMarker.show()\r\n .offset({top, left: left - 20})\r\n .text(end);\r\n }\r\n }\r\n }\r\n });\r\n }, function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n $(\".\" + clazz).css(\"background-color\", \"\");\r\n $(this).closest(\".problemindexholder\").find(\".testCaseMarker_\" + end).hide();\r\n }\r\n }\r\n });\r\n });\r\n\r\n });\r\n</script>\r\n\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 05:38:35</span> (j3).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/73366/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/73366/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/73366/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/73366/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-73366.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'8122c4ccbe751604',t:'MTY5NjY0NjMxNS4wODYwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"},"long_tags":{"kind":"string","value":"[\"Geometry, computational geometry\"]"},"short_tags":{"kind":"string","value":"[\"geometry\", \"*3100\"]"},"tutorial_link":{"kind":"string","value":"https://codeforces.com/blog/entry/10629"},"tutorial_page":{"kind":"string","value":"\r\n\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"74361418aed3add319d25ce966ceafdf\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"h1\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Codeforces Round #228 — Editorial - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n \n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Codeforces Round #228 — Editorial - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/81027/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/81027/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/81027/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/81027/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/81027/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/81027/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/81027/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/81027/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/81027/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/81027/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/81027/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/81027/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/81027/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/81027/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/573cedc6b04c15481941f418269f4057/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='74361418aed3add319d25ce966ceafdf'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/81027/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fblog%2Fentry%2F10629\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='74361418aed3add319d25ce966ceafdf'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Pay attention\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n <div style=\"text-align:center;border-bottom: 1px solid rgb(185, 185, 185);margin:0 -0.5em 0.5em -0.5em;padding: 0 1em 0.5em 1em;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 1, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:51:54</span><br/><a href=\"/contestRegistration/1876\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n <div style=\"text-align:center;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 2, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:51:54</span><br/><a href=\"/contestRegistration/1877\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='74361418aed3add319d25ce966ceafdf'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n </label>\r\n </div>\r\n <div style=\"padding: 0 1em 1em 1em;text-align:right;\">\r\n <input style=\"height:1.65em;padding:0 0.75em;\" type=\"submit\" value=\"Find\"/>\r\n </div>\r\n </form>\r\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".handleBox\").autocomplete(\"/data/handles\", {\r\n delay: 200,\r\n width: 200,\r\n selectFirst: false,\r\n matchContains: true,\r\n minChars: 3\r\n });\r\n $(\".handleForm\").attr(\"autocomplete\", \"off\").submit(function () {\r\n var link = \"/profile/userHandle\".replace(\r\n \"userHandle\", $(this).find(\".handleBox\").val()\r\n );\r\n window.location = link;\r\n return false;\r\n });\r\n });\n </script>\n\r\n\r\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Recent actions\n <div class=\"top-links\">\n </div>\n </div>\n <div class=\"recent-actions\">\r\n <ul>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/121073\">Meta Hacker Cup 2023 Round 1</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/.Danet\" title=\"Expert .Danet\" class=\"rated-user user-blue\">.Danet</a> →\r\n <a href=\"/blog/entry/121172\">[TLE on pretest1]</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\" class=\"rated-user user-red\">Pyqe</a> →\r\n <a href=\"/blog/entry/121025\">Codeforces Round #902 (Div. 1, Div. 2, based on COMPFEST 15 — Final Round)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pranshu_Pandya\" title=\"Specialist Pranshu_Pandya\" class=\"rated-user user-cyan\">Pranshu_Pandya</a> →\r\n <a href=\"/blog/entry/121171\">An Interesting Tree Problem</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/sszcdjr\" title=\"Master sszcdjr\" class=\"rated-user user-orange\">sszcdjr</a> →\r\n <a href=\"/blog/entry/119859\">Codeforces Round 896 (Div. 1, Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/119880\">It's Happening! Meta Hacker Cup 2023 Schedule</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/DaviddeGea1\" title=\"Expert DaviddeGea1\" class=\"rated-user user-blue\">DaviddeGea1</a> →\r\n <a href=\"/blog/entry/70917\">Number of ways of dividing an array into 2 parts such that sum of each part is > k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bekh\" title=\"Master Bekh\" class=\"rated-user user-orange\">Bekh</a> →\r\n <a href=\"/blog/entry/74245\">Questions and doubts regarding Aliens DP trick</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a> →\r\n <a href=\"/blog/entry/8192\">Codeforces Round #190 — Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/hocky\" title=\"Candidate Master hocky\" class=\"rated-user user-violet\">hocky</a> →\r\n <a href=\"/blog/entry/95323\">FBHC wuining uw Day? Incwease uw stacc size! (ㅅ´ ˘ `)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/liouzhou_101\" title=\"International Master liouzhou_101\" class=\"rated-user user-orange\">liouzhou_101</a> →\r\n <a href=\"/blog/entry/87598\">Editorial of Codeforces Round #700</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/yeon_gist\" title=\"Newbie yeon_gist\" class=\"rated-user user-gray\">yeon_gist</a> →\r\n <a href=\"/blog/entry/121170\">plusMinusPermutation computing error</a>\r\n <img alt=\"Text created or updated\" title=\"Text created or updated\" src=\"//codeforces.org/s/81027/images/icons/x-update-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/altforminuscontribution\" title=\"Newbie altforminuscontribution\" class=\"rated-user user-gray\">altforminuscontribution</a> →\r\n <a href=\"/blog/entry/121162\">My screen get unexpectedly big, what should I do</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/atcoder_official\" title=\"Unrated, atcoder_official\" class=\"rated-user user-black\">atcoder_official</a> →\r\n <a href=\"/blog/entry/121120\">We will hold UNIQUE VISION Programming Contest 2023 Autumn(AtCoder Beginner Contest 323)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/YouStill_DontKnowMeYet\" title=\"Candidate Master YouStill_DontKnowMeYet\" class=\"rated-user user-violet\">YouStill_DontKnowMeYet</a> →\r\n <a href=\"/blog/entry/117659\">[GYM] Al-Baath Collegiate Programming Contest 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/ankancool\" title=\"Expert ankancool\" class=\"rated-user user-blue\">ankancool</a> →\r\n <a href=\"/blog/entry/121136\">Invitation to AstroByte 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/GeZhiyuan\" title=\"Grandmaster GeZhiyuan\" class=\"rated-user user-red\">GeZhiyuan</a> →\r\n <a href=\"/blog/entry/120943\">Codeforces Round 901 (Div. 1, Div. 2) Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a> →\r\n <a href=\"/blog/entry/120772\">PSA: Increase your stack size before the Meta Hacker Cup, here's how</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/dino_merlin\" title=\"Expert dino_merlin\" class=\"rated-user user-blue\">dino_merlin</a> →\r\n <a href=\"/blog/entry/121145\">Intuitive approach for CEOI Kangaroo?</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/icecuber\" title=\"Grandmaster icecuber\" class=\"rated-user user-red\">icecuber</a> →\r\n <a href=\"/blog/entry/70018\">CSES DP section editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bn00b\" title=\"Newbie Bn00b\" class=\"rated-user user-gray\">Bn00b</a> →\r\n <a href=\"/blog/entry/98820\">[FEATURE REQUEST : ATCODER] TOPICS TAGS AND SORTING BY SOLVE COUNT</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a> →\r\n <a href=\"/blog/entry/121163\">AtCoder Regular Contest 166 Announcement</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/windva\" title=\"Grandmaster windva\" class=\"rated-user user-red\">windva</a> →\r\n <a href=\"/blog/entry/120644\">Codeforces Round 899 (Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Misa-Misa\" title=\"Expert Misa-Misa\" class=\"rated-user user-blue\">Misa-Misa</a> →\r\n <a href=\"/blog/entry/121157\">Someone please help me understand this.</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/shivam565\" title=\"Specialist shivam565\" class=\"rated-user user-cyan\">shivam565</a> →\r\n <a href=\"/blog/entry/108348\">Total number of subarrays with sum atmost k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n </ul>\r\n </div>\r\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/recent-actions\">Detailed →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n</div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li><a\r\n href=\"/profile/cgy4ever\">cgy4ever</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/cgy4ever\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/cgy4ever\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/cgy4ever\">Submissions</a></li>\r\n <li><a\r\n href=\"/groups/with/cgy4ever\">Groups</a></li>\r\n <li><a\r\n href=\"/contests/with/cgy4ever\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/cgy4ever\">Problemsetting</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/cgy4ever\" style=\"text-decoration:none;color:black !important;\">cgy4ever's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"10684\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/10629\"> <p>Codeforces Round #228 — Editorial</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a>,\r\n <span class=\"format-humantime\" title=\"Feb/03/2014 22:14\">10 years ago</span>,\r\n \r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p>You can find the editorial and my solutions here: <a href=\"https://github.com/cgy4ever/CF228\">https://github.com/cgy4ever/CF228</a></p><p><a href=\"/contest/389/problem/A\" title=\"Codeforces Round 228 (Div. 2)\">389A - Fox and Number Game</a></p><p>First we know that: in the optimal solution, all number will be equal: otherwise we can pick a and b (a < b) then do b = b — a, it will make the answer better.</p><p>Then we need an observation: after each operation, the GCD (Greatest common divisor) of all number will remain same. It can be proved by this lemma: if g is a divisor of all number of x[], then after the operation, g is still the divisor of these numbers, and vice versa.</p><p>So in the end, all number will become the GCD of x[].</p><p>Another solution that can pass is: While there exist x[i] > x[j], then do x[i] -= x[j]. We can select arbitrary i and j if there exist more than 1 choice.</p><p><a href=\"/contest/389/problem/B\" title=\"Codeforces Round 228 (Div. 2)\">389B - Fox and Cross</a></p><p>Let's define the first # of a shape is the cell contain # that have the lexicographical smallest coordinate. Then the first # of a cross is the top one.</p><p>Then let x be the first # of the given board. (If the board is empty, then we can draw it with zero crosses.) x must be covered by a cross, and x must be the first # of the cross. (You can try 4 other positions, it will cause a lexicographical smaller # in the board than x)</p><p>So we try to cover this x use one cross, if it leads some part of the cross covers a '.', then there will be no solution. If not, we just reduce the number of # in the board by 4, we can do this again and again.</p><p><a href=\"/contest/389/problem/C\" title=\"Codeforces Round 228 (Div. 2)\">389C - Fox and Box Accumulation</a> / <a href=\"/contest/388/problem/A\" title=\"Codeforces Round 228 (Div. 1)\">388A - Fox and Box Accumulation</a></p><p>We need some observation:</p> <ol> <li><p>There exists an optimal solution such that: in any pile, the box on the higher position will have a smaller strength.</p></li> <li><p>Let k be the minimal number of piles, then there exists an optimal solution such that: The height of all piles is n/k or n/k+1 (if n%k=0, then all of them have the height n/k).</p></li> </ol><p>We can prove them by exchange argument: from an optimal solution, swap the boxes in it to make above property holds, and we can ensure it will remain valid while swapping.</p><p>Then for a given k, we can check whether there exist a solution: the i-th (indexed from 0) smallest strength needs to be at least i/k.</p><p>So we can do binary search (or just enumerate, since n is only 100) on k.</p><p><a href=\"/contest/389/problem/D\" title=\"Codeforces Round 228 (Div. 2)\">389D - Fox and Minimal path</a> / <a href=\"/contest/388/problem/B\" title=\"Codeforces Round 228 (Div. 1)\">388B - Fox and Minimal path</a></p><p>First we need to know how to calculate the number of different shortest paths from vertex 1 to vertex 2: it can be done by dp: dp[1] = 1, dp[v] = sum{dp[t] | dist(1,t) = dist(1,v) — 1}, then dp[2] is our answer.</p><p>We need to do dp layer by layer. (first we consider vertexes have distance 1 to node 1, then vertexes have distance 2 to node 1 and so on.) So we can construct the graph layer by layer, and link edges to control the dp value of it.</p><p>My solution is construct the answer by binary express: If k is 19, then we need some vertexes in previous layer such that the dp value is 16, 2 and 1. So we just need a way to construct layer with dp value equals to 2^k.</p><p>In the first layer, it contains one node: 1, it has the dp value 1. In the next layer, we can construct 2 nodes, with dp value equals to 1. (We use [1 1] to denote it). And the next layer is [1 1 2], then [1 1 2 4], [1 1 2 4 8] and so on. So we need about 30 layers such that gets all 2^k where k < 30. It uses about 500 nodes.</p><p><a href=\"/contest/389/problem/E\" title=\"Codeforces Round 228 (Div. 2)\">389E - Fox and Card Game</a> / <a href=\"/contest/388/problem/C\" title=\"Codeforces Round 228 (Div. 1)\">388C - Fox and Card Game</a></p><p>First let's consider the case which all piles have even size. In this case, we can prove: in the optimal play, Ciel will gets all top most half cards of each pile, and Jiro gets the remain cards.</p><p>We can prove by these facts: Ciel have a strategy to ensure she can get this outcome and Jiro also have a strategy to ensure this outcome. (For Jiro this strategy is easy: just pick the card from pile that Ciel have just picked. For Ciel it's a little bit harder.)</p><p>Why we can conclude they are both the optimal strategy? Ciel just can't win more, because if she played with Jiro with above strategy, Jiro will get the bottom half of each pile.</p><p>Then we come back with cases that contain odd size piles. The result is: for odd size pile, Ciel will get the top (s-1)/2 cards and Jiro will get the bottom (s-1)/2 cards. Then what about the middle one? Let's denote S is all such middle cards. Then we define a reduced game: In each turn, they pick one card from S. The optimal play for this game is easy: Ciel gets the max one, and Jiro gets the 2nd largest one, and Ciel gets the 3rd largest one and so on.</p><p>We can prove Ciel have a strategy to get: all top half parts + cards she will get in the optimal play in the reduced game. And Jiro also have a strategy to get: all bottom half parts + cards he will get in the optimal play in the reduced game. And these strategy are optimal.</p><p><a href=\"/contest/388/problem/D\" title=\"Codeforces Round 228 (Div. 1)\">388D - Fox and Perfect Sets</a></p><p>A perfect set correspond to a linear space, so we can use base to represent it. We do the Gauss–Jordan elimination of vectors in that set, and can get an unique base. (Note that we need to to the all process of Gauss–Jordan elimination, including the elimination after it reached upper triangular)</p><p>And we can construct the bases bit by bit from higher bit to lower, for a bit:</p> <ol> <li><p>We can add a vector to the base such that the bit is the highest bit of that vector. And at this time, all other vector will have 0 in this bit.</p></li> <li><p>Otherwise we need to assign this bit of each vector already in the base. If now we have k vector, then we have 2^k choices.</p></li> </ol><p>And when we do this, we need to know what's the maximal vector in this space. It's not hard:</p> <ol> <li><p>If we add a vector, then in the maximal vector, this bit will be 1.</p></li> <li><p>Otherwise, if we don't have any vector in base yet, then this bit will be 0. Otherwise there will be 2^(k-1) choices results in this bit of maximal vector will be 0, and 2^(k-1) choices results in 1.</p></li> </ol><p>So we can solve this task by DP bit by bit.</p><p><a href=\"/contest/388/problem/E\" title=\"Codeforces Round 228 (Div. 1)\">388E - Fox and Meteor Shower</a></p><p>All tasks beside this are very easy to code. And this one focus on implementation.</p><p>We can represent the orbit of each meteor by a line in 3D space. (we use an axis to represent the time, and two axis to represent the position on the plane.)</p><p>Then the problem becomes: we have some lines in 3D space (they are not complete coincide), find a largest clique such that each pair of lines touch at some point.</p><p>We need this observation: If there are 3 lines in the optimal clique, and these 3 lines are not share a common point, then all line in this clique will on a plane.</p><p>By using this observation, we only need to consider 2 cases:</p> <ol> <li><p>All lines in the clique have a common point.</p></li> <li><p>All lines in the clique are on the same plane.</p></li> </ol><p>Both are easy tasks in theory, but it needs some coding.</p><p>There are two ways:</p> <ol> <li><p>Use integer anywhere. Note that the coordinates of intersection can be rational number, but can't be irrational, so we could do this. We can use some way to encode the plane, direction.</p></li> <li><p>Use floating number. To count same number of points, we can sort (x, y, z) by using the following compare function: if (abs(A.x — B.x) > eps){return A.x < B.x} otherwise { if(abs(A.y-B.y)>eps){return A.y < B.y} otherwise return A.z < B.z}.</p></li> </ol></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/388\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 228 (Div. 1)</a> </span>\r\n </div>\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/389\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 228 (Div. 2)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-21-10684\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"21\",\n blogEntryId: \"10629\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-10684\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+45</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-10684\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/cgy4ever\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/cgy4ever\">\n cgy4ever\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Feb/03/2014 22:14\">10 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/10629#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/10629#comments\">\n 44\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"10700\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (39)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159842\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/YaleZ\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/24526/avatar/5b17db1affad55a5.jpg'/> </a>\n <div><a href=\"/profile/YaleZ\" title=\"Expert YaleZ\" class=\"rated-user user-blue\">YaleZ</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2014 22:38\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159842\" href=\"?#comment-159842\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"159842\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"159842\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"24526\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159842\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thank for timely editorial. I think Markdown is better when publish something on Github. Isn't it?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159842 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159842 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159842\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159846\" commentParentId=\"159842\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/cgy4ever\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2014 22:43\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159846\" href=\"?#comment-159846\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159842\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159846\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"11\"\r\n data-commentUserId=\"62\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+11</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159846\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Yes, I'm working on it. :)</p><p>The website seems to be not stable at this time. So I post them in other sites to ensure all people can see it.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159846 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159846 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159846\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159857\" commentParentId=\"159846\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Nodir.Daminov\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/71439/avatar/d6d2016f6dfe5ecd.jpg'/> </a>\n <div><a href=\"/profile/Nodir.Daminov\" title=\"Candidate Master Nodir.Daminov\" class=\"rated-user user-violet\">Nodir.Daminov</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2014 22:58\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159857\" href=\"?#comment-159857\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159846\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159857\" class=\"CommentVoteFrame\"\r\n class=\"too-negative-comment-vote\"\r\n data-commentRating=\"-35\"\r\n data-commentUserId=\"71439\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-35</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159857\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Maaan is it so hard to COPY ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159857 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159857 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159857\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159874\" commentParentId=\"159857\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/cgy4ever\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2014 23:19\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159874\" href=\"?#comment-159874\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159857\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159874\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"12\"\r\n data-commentUserId=\"62\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+12</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159874\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Sorry for the delay.</p><p>When I was submitting my post that contains the editorial, it always returns "Codeforces is now unavailable." so I just can't post it.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159874 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159874 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159874\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159859\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/BishalG\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/60637/avatar/d21ddf49bbd1630c.jpg'/> </a>\n <div><a href=\"/profile/BishalG\" title=\"Expert BishalG\" class=\"rated-user user-blue\">BishalG</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2014 22:58\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159859\" href=\"?#comment-159859\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159859\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"60637\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159859\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Nice problemSets @<a class=\"rated-user user-orange\" href=\"/profile/cgy4ever\" title=\"International Master cgy4ever\">cgy4ever</a> , although I misunderstood the problem-B <a href=\"/contest/389/problem/B\" title=\"Codeforces Round 228 (Div. 2)\">389B - Fox and Cross</a> upto 1 hrs :( </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159859 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159859 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159859\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159867\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Mr.ink\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Mr.ink\" title=\"Expert Mr.ink\" class=\"rated-user user-blue\">Mr.ink</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2014 23:07\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159867\" href=\"?#comment-159867\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159867\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"128876\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159867\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>due to my slow internet speed i can not see your editorial on github because my country internet has problem with https! </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159867 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159867 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159867\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159881\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Mr.ink\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Mr.ink\" title=\"Expert Mr.ink\" class=\"rated-user user-blue\">Mr.ink</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2014 23:38\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159881\" href=\"?#comment-159881\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159881\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"128876\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159881\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>does anyone have a better solution for div2 C problem?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159881 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159881 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159881\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159883\" commentParentId=\"159881\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/t_thirupathi\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/146179/avatar/98c28348196ce4ca.jpg'/> </a>\n <div><a href=\"/profile/t_thirupathi\" title=\"Specialist t_thirupathi\" class=\"rated-user user-cyan\">t_thirupathi</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2014 23:42\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159883\" href=\"?#comment-159883\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159881\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159883\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"146179\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159883\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Have a look at mine <a href=\"/contest/389/submission/5878414\" title=\"Submission 5878414 by t_thirupathi\">5878414</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159883 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159883 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159883\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159909\" commentParentId=\"159883\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/9charles\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/119814/avatar/653156a3153bc2dd.jpg'/> </a>\n <div><a href=\"/profile/9charles\" title=\"Expert 9charles\" class=\"rated-user user-blue\">9charles</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 06:46\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159909\" href=\"?#comment-159909\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159883\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159909\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"119814\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159909\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can you explain it?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159909 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159909 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159909\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159907\" commentParentId=\"159881\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/k790alex\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/119882/avatar/4baeddca65b2b958.jpg'/> </a>\n <div><a href=\"/profile/k790alex\" title=\"Specialist k790alex\" class=\"rated-user user-cyan\">k790alex</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 06:28\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159907\" href=\"?#comment-159907\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159881\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159907\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"119882\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159907\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I don't know if this is a better way but I didt in the contest.</p><p>Start making a pile with the low strength and while possible, look for a box that can support at least 1 box, then at least 2 boxes, 3, etc, repeat it while you have boxes.</p><p>My solution: <a href=\"/contest/389/submission/5879464\" title=\"Submission 5879464 by k790alex\">5879464</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159907 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159907 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159907\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159914\" commentParentId=\"159907\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/YaleZ\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/24526/avatar/5b17db1affad55a5.jpg'/> </a>\n <div><a href=\"/profile/YaleZ\" title=\"Expert YaleZ\" class=\"rated-user user-blue\">YaleZ</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 07:38\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159914\" href=\"?#comment-159914\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159907\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159914\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"24526\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159914\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Greedy is also a nice solution.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159914 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159914 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159914\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159932\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/worfzyq\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/157364/avatar/8f104a361ed91be8.jpg'/> </a>\n <div><a href=\"/profile/worfzyq\" title=\"Expert worfzyq\" class=\"rated-user user-blue\">worfzyq</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 09:52\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159932\" href=\"?#comment-159932\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159932\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"157364\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159932\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>388C — Fox and Card Game This problem is good magic</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159932 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159932 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159932\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159935\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/orchidmajumder\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/63603/avatar/f8db3747466a7168.jpg'/> </a>\n <div><a href=\"/profile/orchidmajumder\" title=\"Specialist orchidmajumder\" class=\"rated-user user-cyan\">orchidmajumder</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 10:07\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159935\" href=\"?#comment-159935\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"159935\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"159935\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"7\"\r\n data-commentUserId=\"63603\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+7</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159935\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>hii everyone,in Div II E,I can't understand why the optimal play for JIRO is to take the bottom most card from the same pile from where CIEL is picking?should not it try to pick the maximum value among all bottom most card at it's every move??</p><p>Please someone explain why the strategy presented in the editorial is optimal.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159935 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159935 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159935\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159948\" commentParentId=\"159935\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Zzyzx\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/86049/avatar/c698ee674460e7eb.jpg'/> </a>\n <div><a href=\"/profile/Zzyzx\" title=\"Expert Zzyzx\" class=\"rated-user user-blue\">Zzyzx</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 13:07\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159948\" href=\"?#comment-159948\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159935\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159948\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"86049\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159948\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Ok, I'm afraid I do not have a rigorous proof for this. I'll just explain to you why I think it is right.</p><p>First of all, we need to understand that both Ciel and Jiro are smart. Now, whenever it is Ciel's turn, he will pick the "best pile" and try to take everything from that pile and then move on to the next "best pile". Jiro knows that his friend Ciel is smart, so he will try to stop him from taking everything. This can be done only if he picks from the same pile that Ciel does.</p><p>But your question is — what if there is a different pile whose bottom-most card is much better than the bottom-most card of the pile from which Ciel is picking right?</p><p>My answer to this is that, this situation will never arise. Because if there is such a pile, then Ciel will try to take that card in the first place and therefore, Ciel will be picking from the same pile that Jiro will want to pick from.</p><p>Am I making sense? Or is there a flaw in my argument?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159948 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159948 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159948\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159952\" commentParentId=\"159948\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/orchidmajumder\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/63603/avatar/f8db3747466a7168.jpg'/> </a>\n <div><a href=\"/profile/orchidmajumder\" title=\"Specialist orchidmajumder\" class=\"rated-user user-cyan\">orchidmajumder</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 13:32\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159952\" href=\"?#comment-159952\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159948\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159952\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"63603\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159952\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Yes I'm also thinking along the same line.Both are playing optimally and if Ciel is chosing any pile then jiro knows that this pile has better cards in the botttom half.So he won't choose ciel to take the advantage and vice versa.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159952 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159952 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159952\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159944\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hzyfr\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/hzyfr\" title=\"Expert hzyfr\" class=\"rated-user user-blue\">hzyfr</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 12:27\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159944\" href=\"?#comment-159944\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159944\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"129936\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159944\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I have a different idea on D div1 <a href=\"/contest/388/problem/D\" title=\"Codeforces Round 228 (Div. 1)\">388D - Fox and Perfect Sets</a> but I failed on getting some relations in one step.</p><p>Let <em>M</em> be the maximum element in set <em>S</em> . Then if <em>S</em> is a perfect set, its elements should have all bits equals <em>0</em> on positions in <em>M's</em> binary representation(otherwise there must exist another element bigger than <em>M</em>). So let <em>cnt</em> = (number of 1's in binary repersentation of <em>M</em>), then the number of perfect sets which has <em>M</em> as its greatest element is determined by <em>cnt</em> . Well, this is the step I can't come up with a solution(actually the target is to find the number of perfect sets which has <code>2^cnt-1</code> as its greatest element).</p><p>Then the last step is simple. We can apply something like doubling algorithm on the problem.</p><p>We are asked to find the number of perfect sets with all the elements not greater than <em>N</em> . Let's suppose <em>N+1</em> is a power of 2 then its easy to calculate how many numbers not greater than <em>N</em> has <em>cnt</em> = 1,2,...m where m is the length of <em>N</em> in binary representation. That's just simple combinatoric number <em>C(n,i) (1<=i<=n)</em> . And if we have done the previous step, it's easy to get the result.</p><p>Then think about common cases of <em>N</em> . Let's take the highest bit of N and since all above bits are determined, the number of 1's will just add a constant value. So calculate this part and subtract that highest bit of <em>N</em> and do the same thing on remaining value of <em>N</em> , until <em>N=0</em> . At that time we will get the correct answer. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159944 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159944 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159944\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159945\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/rexdf\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/23738/avatar/797fa665fbe1ca78.jpg'/> </a>\n <div><a href=\"/profile/rexdf\" title=\"Specialist rexdf\" class=\"rated-user user-cyan\">rexdf</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 12:36\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159945\" href=\"?#comment-159945\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159945\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"23738\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159945\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>dp[1] = 1, dp[v] = sum{dp[t] | dist(1,t) = dist(1,v) — 1}, then dp[2] is our answer. What's v means? what's '|' means? What's dp[v] means?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159945 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159945 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159945\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159949\" commentParentId=\"159945\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/sancho\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/85894/avatar/e31a4b24327c1000.jpg'/> </a>\n <div><a href=\"/profile/sancho\" title=\"Candidate Master sancho\" class=\"rated-user user-violet\">sancho</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 13:10\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159949\" href=\"?#comment-159949\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159945\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159949\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"85894\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159949\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>v — vertex, answer for which we are getting at this moment, | — means "such as", dp[v] — number of ways from 1 vertex to this one</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159949 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159949 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159949\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159947\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lol12\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/lol12\" title=\"Specialist lol12\" class=\"rated-user user-cyan\">lol12</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 13:04\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159947\" href=\"?#comment-159947\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159947\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"10\"\r\n data-commentUserId=\"152356\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+10</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159947\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can someone please explain solution of Div2-D. Thanx</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159947 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159947 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159947\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"160020\" commentParentId=\"159947\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/YaleZ\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/24526/avatar/5b17db1affad55a5.jpg'/> </a>\n <div><a href=\"/profile/YaleZ\" title=\"Expert YaleZ\" class=\"rated-user user-blue\">YaleZ</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/05/2014 07:07\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-160020\" href=\"?#comment-160020\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159947\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"160020\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"9\"\r\n data-commentUserId=\"24526\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+9</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-160020\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>You can think about binnary. Such as (13)10=(1101)2=((1+(2+0)*2)+1)*2+1</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-160020 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-160020 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-160020\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"469976\" commentParentId=\"159947\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/roll_no_1\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/631859/avatar/36d157f91f64fe7f.jpg'/> </a>\n <div><a href=\"/profile/roll_no_1\" title=\"Master roll_no_1\" class=\"rated-user user-orange\">roll_no_1</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Nov/09/2018 17:27\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-469976\" href=\"?#comment-469976\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159947\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"469976\" revisionCount=\"4\" revision=\"4\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">4</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"469976\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"631859\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-469976\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Here's my implementation of the editorialist's explanation of Div-2 D / Div-1 B: <a href=\"/contest/388/submission/45480077\" title=\"Submission 45480077 by roll_no_1\">45480077</a>. I implemented the layers as [1], [1, 1], [2, 1, 1], [4, 2, 1, 1] and so on.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-469976 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-469976 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-469976\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159967\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/BENYAM1N\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/84938/avatar/d2ae2657d8898e38.jpg'/> </a>\n <div><a href=\"/profile/BENYAM1N\" title=\"Master BENYAM1N\" class=\"rated-user user-orange\">BENYAM1N</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 15:51\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159967\" href=\"?#comment-159967\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159967\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"13\"\r\n data-commentUserId=\"84938\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+13</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159967\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Very good contest and nice editorial. Hope from now on I see more contests from you.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159967 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159967 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159967\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159984\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/kojak_\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/57722/avatar/38990eea59bc188e.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/kojak_\" title=\"Newbie kojak_\" class=\"rated-user user-gray\">kojak_</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 18:34\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159984\" href=\"?#comment-159984\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159984\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"57722\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159984\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Did anyone come up with a DP solution for Div.2 C/ Div.1 A?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159984 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159984 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159984\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"160012\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/IgorKoval\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/51322/avatar/afc854fff49f072a.jpg'/> </a>\n <div><a href=\"/profile/IgorKoval\" title=\"Candidate Master IgorKoval\" class=\"rated-user user-violet\">IgorKoval</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 23:17\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-160012\" href=\"?#comment-160012\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"160012\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"11\"\r\n data-commentUserId=\"51322\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+11</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-160012\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Объясните, пожалуйста, разбор задачи "388D — Fox and Perfect Sets" на пальцах. Как-нибудь без Гаусса и базисов. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-160012 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-160012 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-160012\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"160016\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Mr.ink\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Mr.ink\" title=\"Expert Mr.ink\" class=\"rated-user user-blue\">Mr.ink</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/05/2014 01:08\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-160016\" href=\"?#comment-160016\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"160016\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"128876\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-160016\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>fox and card games is a great problem.thanks!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-160016 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-160016 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-160016\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"160037\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/yaswanth\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/yaswanth\" title=\"Specialist yaswanth\" class=\"rated-user user-cyan\">yaswanth</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/05/2014 18:38\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-160037\" href=\"?#comment-160037\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"160037\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"9\"\r\n data-commentUserId=\"96196\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+9</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-160037\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can anyone explain div2 C question? I did not understand the editorial.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-160037 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-160037 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-160037\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"160063\" commentParentId=\"160037\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/YaleZ\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/24526/avatar/5b17db1affad55a5.jpg'/> </a>\n <div><a href=\"/profile/YaleZ\" title=\"Expert YaleZ\" class=\"rated-user user-blue\">YaleZ</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/06/2014 05:46\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-160063\" href=\"?#comment-160063\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-160037\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"160063\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"24526\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-160063\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>s[i]>=i/k -> k*s[i]>=i There are i boxes' strength smaller than i-th box. So we need to check if the boxes before i-th can be held.</p><p>(I don't know whether I have understood correctly...)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-160063 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-160063 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-160063\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"160053\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/yada\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/142663/avatar/49901b54d1c5f019.jpg'/> </a>\n <div><a href=\"/profile/yada\" title=\"Candidate Master yada\" class=\"rated-user user-violet\">yada</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/05/2014 23:24\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-160053\" href=\"?#comment-160053\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"160053\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"142663\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-160053\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Great Problem! I really enjoy it.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-160053 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-160053 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-160053\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"364019\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lnzva\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/305672/avatar/cf6c09a214141751.jpg'/> </a>\n <div><a href=\"/profile/lnzva\" title=\"Expert lnzva\" class=\"rated-user user-blue\">lnzva</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/02/2017 22:06\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-364019\" href=\"?#comment-364019\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"364019\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"364019\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"305672\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-364019\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In 388C, I'm having a hard time understanding why Jiro's optimal strategy would be to pick the pile Ciel just picked. Why not pick a pile which has a better bottom part than the one Ciel is picking? According to some comments, Ciel would then pick from the second pile-what if another pile has a much better top part? Could someone please help? I saw this problem first 6 months ago, and I had a hard time understanding why this greedy is correct; I saw this problem again today and am having trouble with it again, with no progress.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-364019 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-364019 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-364019\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"647866\" commentParentId=\"364019\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/_wzx27\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1458283/avatar/7d77b62012ae2398.jpg'/> </a>\n <div><a href=\"/profile/_wzx27\" title=\"Candidate Master _wzx27\" class=\"rated-user user-violet\">_wzx27</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/22/2020 18:33\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-647866\" href=\"?#comment-647866\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-364019\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"647866\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1458283\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-647866\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Let's consider such a two-piles situation:</p><p><em>111100</em></p><p><em>001111</em></p><p>is better for Ciel.</p><p>"1" means this card is picked by Ciel,while "0" by Jiro.</p><p>We know that better for Ciel means worse for Jiro.</p><p>So if</p><p><em>111100</em></p><p><em>001111</em></p><p>is better than</p><p><em>111000</em></p><p><em>000111</em></p><p>for Ciel.</p><p>Then when Ciel picked the <strong>first three cards</strong> from <strong>pile 1</strong>,Jiro can just pick the <strong>last three cards</strong> from <strong>pile 1</strong> and finally lead to the result:</p><p><em>111000</em></p><p><em>000111</em></p><p>which is not better for Ciel.</p><p>Generally, if the final result is not balance(half from top and half from bottom) while balance is better than such result for Jiro, Jiro has the ability to adjust it to be balance.So do Ciel.</p><p>Therefore,it reaches balance.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-647866 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-647866 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-647866\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"407776\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/madhur4127\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/568692/avatar/c7d62cc23c758819.jpg'/> </a>\n <div><a href=\"/profile/madhur4127\" title=\"Specialist madhur4127\" class=\"rated-user user-cyan\">madhur4127</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/15/2018 13:06\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-407776\" href=\"?#comment-407776\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"407776\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"568692\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-407776\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>@<a class=\"rated-user user-red\" href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\">cgy4ever</a>, github link shows 404 error(Page not found). Kindly fix it.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-407776 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-407776 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-407776\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"416354\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/introverted\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/657339/avatar/7a6edb1ecc1d3e09.jpg'/> </a>\n <div><a href=\"/profile/introverted\" title=\"Expert introverted\" class=\"rated-user user-blue\">introverted</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/23/2018 11:48\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-416354\" href=\"?#comment-416354\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"416354\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"657339\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-416354\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I solved the DIV1B problem with simple recursion and Divide and Conquer.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-416354 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-416354 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-416354\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"427890\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Nuu\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/652228/avatar/d59867d6477379dc.jpg'/> </a>\n <div><a href=\"/profile/Nuu\" title=\"Candidate Master Nuu\" class=\"rated-user user-violet\">Nuu</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/01/2018 22:33\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-427890\" href=\"?#comment-427890\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"427890\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"652228\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-427890\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can anyone give me some examples of the similar problems to DivC?? I think this problem is very nice for train brain xD</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-427890 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-427890 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-427890\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"629609\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/The_Alchemist\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1275181/avatar/662970aa05d3dfc5.jpg'/> </a>\n <div><a href=\"/profile/The_Alchemist\" title=\"Expert The_Alchemist\" class=\"rated-user user-blue\">The_Alchemist</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/25/2020 21:47\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-629609\" href=\"?#comment-629609\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"629609\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1275181\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-629609\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I know I am very late but can someone pls explain to me div 2C/div1A. Thanks in advance... </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-629609 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-629609 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-629609\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"641010\" commentParentId=\"629609\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/kstheking\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1160931/avatar/e144fc7b0fdb90b1.jpg'/> </a>\n <div><a href=\"/profile/kstheking\" title=\"Pupil kstheking\" class=\"rated-user user-green\">kstheking</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/13/2020 14:47\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-641010\" href=\"?#comment-641010\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-629609\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"641010\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1160931\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-641010\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p><a href=\"https://codeforces.com/contest/388/submission/83605110\">https://codeforces.com/contest/388/submission/83605110</a> Here you go, if you don't get it feel free to ask</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-641010 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-641010 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-641010\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"644488\" commentParentId=\"641010\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/tanisha_\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/tanisha_\" title=\"Newbie tanisha_\" class=\"rated-user user-gray\">tanisha_</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/18/2020 15:26\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-644488\" href=\"?#comment-644488\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-641010\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"644488\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1500127\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-644488\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>is this any algorithm</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-644488 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-644488 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-644488\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"647627\" commentParentId=\"644488\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/kstheking\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1160931/avatar/e144fc7b0fdb90b1.jpg'/> </a>\n <div><a href=\"/profile/kstheking\" title=\"Pupil kstheking\" class=\"rated-user user-green\">kstheking</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/22/2020 08:40\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-647627\" href=\"?#comment-647627\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-644488\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"647627\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"647627\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1160931\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-647627\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Well you can call it a greedy algorithm, when we try to apply greedy by placing the heaviest block in bottom, a little problem occurs because of blocks of same strength for example in case of 10 2 2 1 1 0 0<br />If you try to apply greedy by choosing the strongest block<br />10 2 2 1<br />1 0<br />0<br />= 3 heaps<br />Which is wrong answer as sometimes we lose opportunity to create lesser heaps, as in this case if we use the second 2 to make another heap we can do better<br />10 2 1 0<br />2 1 0<br />= 2 heaps<br />So I apply greedy in the reverse direction by picking the smallest strength brick and placing below it the next smallest brick, this way the optimal number of heaps will be formed as in above example<br />choose 0, then you need >= 1, choose 1, then you need >= 2, choose 2, then you need >= 3 choose 10<br />repeat until you have chosen all the bricks<br />If you don't get anything, feel free to ask :) </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-647627 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-647627 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-647627\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"702677\" commentParentId=\"647627\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/breddreamer\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/853067/avatar/240684624b57996.jpg'/> </a>\n <div><a href=\"/profile/breddreamer\" title=\"Newbie breddreamer\" class=\"rated-user user-gray\">breddreamer</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/27/2020 13:01\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-702677\" href=\"?#comment-702677\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-647627\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"702677\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"853067\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-702677\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks, It helped me to understand your solution idea. And finally, I solved this one.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-702677 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-702677 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-702677\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"649225\" commentParentId=\"641010\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/The_Alchemist\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1275181/avatar/662970aa05d3dfc5.jpg'/> </a>\n <div><a href=\"/profile/The_Alchemist\" title=\"Expert The_Alchemist\" class=\"rated-user user-blue\">The_Alchemist</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/24/2020 12:04\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-649225\" href=\"?#comment-649225\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-641010\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"649225\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1275181\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-649225\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>thank you.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-649225 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-649225 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-649225\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n <br/>\r\n\r\n<div id=\"editBox-10700\" style=\"width:50em;display:none;\">\r\n <div class=\"previewBody\" style=\"border: 1px solid #d4d4d4; margin-bottom: 0.5em; padding: 0.25em; display:none;\"> </div>\r\n <div style=\"width: 1px\"> </div>\r\n <div class=\"commentLocale\" style=\"position: relative; top: 0.5em;left:4px;display: none;\">\r\n <input type=\"radio\" name=\"locale\" value=\"en\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In English</span>\r\n <input style=\"margin-left:1em\" type=\"radio\" name=\"locale\" value=\"ru\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In Russian</span>\r\n </div>\r\n <textarea data-drafts-id=\"CommentReplyFrame\" class=\"wysiwyg\" name=\"editContent\" rows=\"20\" style=\"width:99%;\"></textarea>\r\n <div class=\"error error__content\"></div>\r\n <div style=\"text-align:center;\">\r\n <input type=\"button\" name=\"preview\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Preview\"/>\r\n <input type=\"button\" name=\"save\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Save\"/>\r\n </div>\r\n</div>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n\r\nvar firstPreview10700 = true;\r\nvar lastPreviewContent10700 = '';\r\n\r\nif (!window.moveCommentRevision) {\r\n moveCommentRevision = function(e, dir) {\r\n var p = e.parent();\r\n var revisionCount = parseInt(p.attr(\"revisionCount\"));\r\n var revision = parseInt(p.attr(\"revision\"));\r\n var next = revision + dir;\r\n var commentId = p.attr(\"commentId\");\r\n if (next >= 1 && next <= revisionCount) {\r\n $.post(\r\n \"/data/comment-data\",\r\n {action: \"revision\", commentId: commentId, revision: next},\r\n function(json) {\r\n if (json.success == \"true\") {\r\n var parentDiv = e;\r\n\r\n while (parentDiv !== null && (parentDiv[0].nodeName.toLowerCase() !== \"td\" || !parentDiv.hasClass(\"right\"))) {\r\n parentDiv = parentDiv.parent();\r\n }\r\n\r\n if (parentDiv === null) {\r\n return;\r\n }\r\n\r\n parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\").html(json.content);\r\n Codeforces.setupSpoilers(parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\"));\r\n p.attr(\"revision\", next);\r\n p.find(\"span.revision\").text(next);\r\n if (next == 1) {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"visible\");\r\n }\r\n if (next == revisionCount) {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"visible\");\r\n }\r\n\r\n window.updateTypography();\r\n MathJax.Hub.Typeset();\r\n } else {\r\n alert(e.error);\r\n }\r\n },\r\n \"json\"\r\n );\r\n }\r\n };\r\n}\r\n\r\n$(\"div[commentableId=10700] a.leftRevision\").click(function () {\r\n window.moveCommentRevision($(this), -1);\r\n return false;\r\n});\r\n\r\n$(\"div[commentableId=10700] a.rightRevision\").click(function () {\r\n window.moveCommentRevision($(this), +1);\r\n return false;\r\n});\r\n\r\n\r\n\r\n });\n </script>\n\r\n\r\n <script src=\"//codeforces.org/s/81027/js/swfobject-2.2.min.js\" type=\"text/javascript\"></script>\n <script src=\"//codeforces.org/s/81027/js/ftaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n if (window.evercookie) {\n var ec = new evercookie({\n history: false,\n silverlight: false,\n baseurl: '',\n asseturi: '/assets',\n phpuri: '/2fdcd78',\n pngPath: '/eps',\n etagPath: '/ees',\n cachePath: '/ecs'\n });\n\n var randomNumber = function () {\n return Math.random().toString(36).substr(2);\n };\n\n var randomToken = function () {\n return (randomNumber() + randomNumber()).substring(0, 18);\n };\n\n window._ftaa = \"\";\n\n ec.get(\"70a7c28f3de\", function (value) {\n window._ftaa = value;\n if (!window._ftaa) {\n window._ftaa = randomToken();\n ec.set(\"70a7c28f3de\", window._ftaa);\n }\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n } else {\n window._ftaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\n <script src=\"//codeforces.org/s/81027/js/bfaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n var fpCallback = function() {\n Fingerprint2.get({}, function(components) {\n window._bfaa = Fingerprint2.x64hash128(components.map(function (pair) { return pair.value }).join(), 31);\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n };\n if (typeof Fingerprint2 !== 'undefined') {\n if (window.requestIdleCallback) {\n requestIdleCallback(fpCallback)\n } else {\n setTimeout(fpCallback, 500)\n }\n } else {\n window._bfaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"a.new-root-comment\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n\r\n $(\".comment-table .reply a\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".vote-for-comment\").mouseover(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").mouseout(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").click(function () {\r\n var vote = $(this);\r\n var commentId = $(this).parent().attr(\"commentid\");\r\n var commentRating = $(this).parent().attr(\"data-commentRating\");\r\n var direction = $(this).attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n $.post(\"/data/comment/vote\", {commentId: commentId, _tta: Codeforces.tta(), vote: direction, commentRating: commentRating}, function(data) {\r\n if (direction != 0 && !ownComment && data[\"success\"] == \"true\") {\r\n vote.parent().find(\".vote-for-comment\").attr(\"voteDirection\", 0);\r\n if (direction == 1)\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n else {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.closest(\".CommentVoteFrame\").find(\".ComplaintFrame\").css(\"display\", \"inline-block\");\r\n }\r\n vote.find(\"img\").attr(\"popacity\", \"1.0\");\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n vote.parent().find(\".commentRating\").html(data[\"commentRating\"]);\r\n }\r\n Codeforces.showMessage(data[\"message\"]);\r\n }, \"json\");\r\n return false;\r\n });\r\n\r\n $(\".negative-comment-vote\").closest(\".comment-table\").addClass(\"comment-bad\");\r\n\r\n $(\".troll-comment-vote\").closest(\".comment\").css(\"display\", \"none\");\r\n\r\n $(\".too-negative-comment-vote\").closest(\".comment-table\").each(function () {\r\n var e = $(this);\r\n e.addClass(\"comment-too-bad\");\r\n var commentId = e.attr(\"commentId\");\r\n $(\"<div class='bad-comment-replacement ttypography'>The comment is hidden because of too negative feedback, click <a href=# class=show-bad-comment-link>here</a> to view it</div>\").appendTo(\r\n e.find(\".right\")\r\n );\r\n e.find(\".comment-content\").hide();\r\n e.find(\".show-bad-comment-link\").click(function () {\r\n e.find(\".comment-content\").show();\r\n e.find(\".bad-comment-replacement\").hide();\r\n return false;\r\n });\r\n });\r\n });\n </script>\n </div>\r\n\r\n <style type=\"text/css\">\r\n .new-comments-box {\r\n padding: 0.5em;\r\n width: 22px;\r\n font-size: 1.3rem;\r\n font-weight: bold !important;\r\n\r\n position: fixed;\r\n top: 40%;\r\n right: 0;\r\n opacity: 0.2;\r\n color: white;\r\n text-align: center;\r\n\r\n border: 1px solid #222;\r\n background-color: #888 !important;\r\n border-radius: 3px;\r\n -moz-border-radius: 3px;\r\n -webkit-border-radius: 3px;\r\n }\r\n\r\n .new-comments-box:hover {\r\n opacity: 1;\r\n }\r\n\r\n .new-comments-box .dir:hover {\r\n background: #3B5998 !important;\r\n cursor: pointer;\r\n }\r\n </style>\r\n\r\n <div class=\"new-comments-box\" data-position=\"outside\" data-index=\"-1\" style=\"display: none;\">\r\n <div class=\"up dir\" title=\"Ctrl+Up\">↑<hr/>\r\n </div>\r\n <div class=\"info\" title=\"New comments\"></div>\r\n <div class=\"down dir\" title=\"Ctrl+Down\">\r\n <hr/>↓\r\n </div>\r\n </div>\r\n\r\n <script>\r\n $(\".show-archived-checkbox\").change(function () {\r\n const checked = $(this).is(\":checked\");\r\n $.post(\"/data/comment-data\", {action: \"setShowArchived\", checked}, function (json) {\r\n if (json[\"success\"] !== \"true\") {\r\n alert(json[\"error\"]);\r\n } else {\r\n if (checked) {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are now displayed\")\r\n } else {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are no longer displayed\")\r\n }\r\n }\r\n });\r\n return false;\r\n });\r\n\r\n function gotoComment(direction) {\r\n var box = $(\".new-comments-box\");\r\n var index = parseInt(box.attr(\"data-index\"));\r\n if (index == -1)\r\n index = 0;\r\n else\r\n index = Math.max(0, Math.min(parseInt(box.find(\".info\").text()) - 1, index + direction));\r\n box.attr(\"data-index\", index);\r\n var comment = $($(\".comment .highlight-blue[commentId]\").get(index));\r\n $('html, body').animate({\r\n 'scrollTop': Math.max(0, comment.offset().top - ($(window).height() - comment.height()) / 2)\r\n });\r\n return false;\r\n }\r\n\r\n $(\".new-comments-box .down\").click(function () {\r\n return gotoComment(1);\r\n });\r\n\r\n $(\".new-comments-box .up\").click(function () {\r\n return gotoComment(-1);\r\n });\r\n\r\n $(document).keydown(function (e) {\r\n var code = (e.keyCode ? e.keyCode : e.which);\r\n if (e.ctrlKey) {\r\n if (code == 38 || code == 40) {\r\n gotoComment(code - 39);\r\n }\r\n }\r\n });\r\n\r\n var newCommentCount = $(\".comment .highlight-blue[commentId]\").length;\r\n if (newCommentCount > 0) {\r\n $(\".new-comments-box .info\").text(newCommentCount);\r\n $(\".new-comments-box\").show();\r\n }\r\n\r\n $('table.comment-table').mouseenter(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").addClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n\r\n $('table.comment-table').mouseleave(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").removeClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n </script>\r\n\r\n\r\n\r\n <script>\r\n function adjustTopicComplainFrames() {\r\n let topicIds = [];\r\n\r\n $(\".has-topic-id\").each(function () {\r\n const $this = $(this);\r\n const topicId = $this.attr(\"topicId\");\r\n if (topicId) {\r\n topicIds.push(topicId);\r\n }\r\n });\r\n\r\n $.post(\"/data/topics\", {\r\n action: \"findComplainableTopicIds\",\r\n topicIds: topicIds.join(\",\")\r\n }, function (json) {\r\n if (json[\"success\"] === \"true\") {\r\n for (const topicId of json[\"complainableTopicIds\"].split(\",\")) {\r\n $(\".has-topic-id[topicId=\" + topicId + \"]\").each(function () {\r\n $(this).find(\".meta .ComplaintFrame\").css(\"display\", \"inline-block\");\r\n });\r\n }\r\n }\r\n }, \"json\");\r\n }\r\n\r\n $(function () {\r\n adjustTopicComplainFrames();\r\n })\r\n </script>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-10684\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 10684, _tta: Codeforces.tta(), topicRevisionId: 36670, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-10684\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 10684, _tta: Codeforces.tta(), topicRevisionId: 36670, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n </div>\r\n </div>\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 22:13:07</span> (h1).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/81027/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/81027/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/81027/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/81027/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-81027.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'812875a2ab4016f4',t:'MTY5NjcwNTk4Ny4yMjQwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"}}},{"rowIdx":1963,"cells":{"problem_id":{"kind":"string","value":"389A"},"contest":{"kind":"string","value":"389"},"problem":{"kind":"string","value":"A"},"lang":{"kind":"string","value":"en"},"problem_title":{"kind":"string","value":"A. Fox and Number Game"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">A. Fox and Number Game</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Fox Ciel is playing a game with numbers now. </p><p>Ciel has <span class=\"tex-span\"><i>n</i></span> positive integers: <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">1</sub></span>, <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">2</sub></span>, ..., <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>n</i></sub></span>. She can do the following operation as many times as needed: select two different indexes <span class=\"tex-span\"><i>i</i></span> and <span class=\"tex-span\"><i>j</i></span> such that <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span> > <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>j</i></sub></span> hold, and then apply assignment <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span> = <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span> - <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>j</i></sub></span>. The goal is to make the sum of all numbers as small as possible.</p><p>Please help Ciel to find this minimal sum.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains an integer <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">2 ≤ <i>n</i> ≤ 100</span>). Then the second line contains <span class=\"tex-span\"><i>n</i></span> integers: <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">1</sub></span>, <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">2</sub></span>, ..., <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>n</i></sub></span> (<span class=\"tex-span\">1 ≤ <i>x</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 100</span>).</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Output a single integer — the required minimal sum.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>2<br/>1 2<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>2<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3<br/>2 4 6<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>6<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>2<br/>12 18<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>12<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>5<br/>45 12 27 30 18<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>15<br/></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>In the first example the optimal way is to do the assignment: <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">2</sub></span> = <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">2</sub></span> - <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">1</sub></span>.</p><p>In the second example the optimal sequence of operations is: <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">3</sub></span> = <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">3</sub></span> - <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">2</sub></span>, <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">2</sub></span> = <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">2</sub></span> - <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">1</sub></span>.</p></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"62e1e1bcd74dc3a407644e997dfdcbd7\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - A - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"f7b10a37dac6b25fba992a730cfa3b90bd8afecf\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - A - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/73366/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/73366/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/73366/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/73366/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/73366/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/73366/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/73366/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/73366/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/73366/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/73366/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/73366/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/73366/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/73366/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/73366/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/sidebar-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/a037fe51637846d9c7c725713cd840ea/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='62e1e1bcd74dc3a407644e997dfdcbd7'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/73366/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/73366/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fcontest%2F389%2Fproblem%2FA%3Flocale%3Den\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"current\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='62e1e1bcd74dc3a407644e997dfdcbd7'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:100%;\"><a style=\"color: black\" href=\"/contest/389\">Codeforces Round 228 (Div. 2)</a></th>\n </tr>\n <tr>\n <td class=\"left bottom\" colspan=\"1\"><span class=\"contest-state-phase\">Finished</span></td>\n </tr>\n </tbody>\n </table>\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Practice?\n <div class=\"top-links\">\n </div>\n </div>\n<div>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Want to solve the contest problems after the official contest ends? Just register for practice and you will be able to submit solutions.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"\" method=\"post\"><input type='hidden' name='csrf_token' value='62e1e1bcd74dc3a407644e997dfdcbd7'/>\r\n <input type=\"hidden\" name=\"action\" value=\"registerForPractice\"/>\r\n <input type=\"submit\" name=\"submit\" value=\"Register for practice\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div> \r\n</div>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox ContestVirtualFrame borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Virtual participation <i class=\"sidebar-caption-icon las la-angle-down\"></i>\r\n\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\" \"\r\n\r\n data-page-url=\"/data/sidebarFrames\"\r\n\r\n>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests.\n\nIf you've seen these problems, a virtual contest is not for you - solve these problems in the archive.\n\nIf you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.\n\nNever use someone else's code, read the tutorials or communicate with other person during a virtual contest.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"/contest/389/virtual\" method=\"get\">\r\n <input type=\"submit\" name=\"submit\" value=\"Start virtual contest\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div>\r\n</div>\r\n <script>\r\n $(function () {\r\n $(\".ContestVirtualFrame .sidebar-caption-icon\").click(function() {\r\n $(this).toggleClass(\"la-angle-down la-angle-right\");\r\n const $target = $(this).parent().next();\r\n $target.toggle();\r\n const dataPageUrl = $target.attr(\"data-page-url\");\r\n const collapsed = $(this).hasClass(\"la-angle-right\");\r\n const params = {\r\n action: \"setCollapsed\",\r\n sidebarFrameSimpleClassName: \"ContestVirtualFrame\",\r\n collapsed\r\n };\r\n $.each($target[0].attributes, function(i, a) {\r\n const name = a.name;\r\n if (name.startsWith(\"data-extra-key-\")) {\r\n const key = a.value;\r\n const keyIndex = parseInt(name.substring(\"data-extra-key-\".length));\r\n const value = $target.attr(\"data-extra-value-\" + keyIndex);\r\n params[key] = value;\r\n }\r\n });\r\n $.post(dataPageUrl, params, function (result) {\r\n if (result[\"success\"] !== \"true\") {\r\n Codeforces.showMessage(\"Failed to save collapsed state.\");\r\n }\r\n }, \"json\");\r\n return false;\r\n });\r\n })\r\n </script>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Problem tags\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Greedy algorithms\">\r\n greedy\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Mathematics including integration, differential equations, etc\">\r\n math\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Difficulty\">\r\n *1000\r\n</span>\r\n </div>\n <div style=\"clear:both;text-align:right;font-size:1.1rem;\">\r\n <span title=\"Please login into the Codeforces\" class=\"notice\">No tag edit access</span>\r\n </div>\r\n</div>\r\n </div>\n\r\n<form id=\"addTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='62e1e1bcd74dc3a407644e997dfdcbd7'/>\r\n <input name=\"action\" type=\"hidden\" value=\"addTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"6400\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<form id=\"removeTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='62e1e1bcd74dc3a407644e997dfdcbd7'/>\r\n <input name=\"action\" type=\"hidden\" value=\"removeTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"6400\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<script type=\"text/javascript\">\r\n $(\".tag-box img\").click(function () {\r\n var tagName = $(this).attr(\"value\");\r\n Codeforces.confirm(\"Are you sure you want to remove this tag?\", function () {\r\n $(\"#removeTagForm input[name=tagName]\").val(tagName);\r\n $(\"#removeTagForm\").submit();\r\n }, function () {\r\n }, \"Yes\", \"No\");\r\n });\r\n\r\n $(\"#addTagLink\").click(function () {\r\n $(this).hide();\r\n $(\"#addTagLabel\").show();\r\n return false;\r\n });\r\n\r\n $(\"#addTagSelect\").change(function () {\r\n var tagName = $(this).val();\r\n if (tagName === \"\") {\r\n $(\"#addTagLabel\").hide();\r\n $(\"#addTagLink\").show();\r\n } else {\r\n $(\"#addTagForm input[name=tagName]\").val(tagName);\r\n $(\"#addTagForm\").submit();\r\n }\r\n });\r\n</script>\r\n\r\n<style type=\"text/css\">\r\n#new-resource-form tr td {\r\npadding-top: 0.5em;\r\n}\r\n#new-resource-form input:not([type=\"submit\"]) {\r\nfont-size: 0.8em;\r\n}\r\n#new-resource-form select {\r\nfont-size: 0.8em;\r\n}\r\n.new-resource-error {\r\nfont-size: 0.8em;\r\n}\r\n.resource-locale {\r\ncolor: #666;\r\nfont-family: Consolas, \"Andale Mono WT\", \"Andale Mono\", \"Lucida Console\", \"Lucida Sans Typewriter\", \"DejaVu Sans Mono\", \"Bitstream Vera Sans Mono\", \"Liberation Mono\", \"Nimbus Mono L\", Monaco, \"Courier New\", Courier, monospace;\r\n}\r\n</style>\r\n<div class=\"roundbox sidebox sidebar-menu borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Contest materials\n<div class=\"top-links\">\n</div>\n</div>\n<ul>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/10605\" title=\"Codeforces Round #228\" target=\"_blank\">Codeforces Round #228</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"2189:2190\" resourceName=\"Announcement\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/10629\" title=\"Codeforces Round #228 — Editorial\" target=\"_blank\">Tutorial <span class=\"resource-locale\">(en)</span></a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"2191\" resourceName=\"Codeforces Round #228 — Editorial\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n</ul>\r\n</div></div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li class=\"current selectedLava\"><a\r\n href=\"/contest/389\">Problems</a></li>\r\n <li><a\r\n href=\"/contest/389/submit\">Submit Code</a></li>\r\n <li><a\r\n href=\"/contest/389/my\">My Submissions</a></li>\r\n <li><a\r\n href=\"/contest/389/status\">Status</a></li>\r\n <li><a\r\n href=\"/contest/389/hacks\">Hacks</a></li>\r\n <li><a\r\n href=\"/contest/389/room/1\">Room</a></li>\r\n <li><a\r\n href=\"/contest/389/standings\">Standings</a></li>\r\n <li><a\r\n href=\"/contest/389/customtest\">Custom Invocation</a></li>\r\n</ul>\r\n</div>\n\r\n <style>\r\n #facebox .content:has(.diff-popup) {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n }\r\n\r\n .testCaseMarker {\r\n position: absolute;\r\n font-weight: bold;\r\n font-size: 1rem;\r\n }\r\n\r\n .diff-popup {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n display: none;\r\n overflow: auto;\r\n }\r\n\r\n .input-output-copier {\r\n font-size: 1.2rem;\r\n float: right;\r\n color: #888 !important;\r\n cursor: pointer;\r\n border: 1px solid rgb(185, 185, 185);\r\n padding: 3px;\r\n margin: 1px;\r\n line-height: 1.1rem;\r\n text-transform: none;\r\n }\r\n\r\n .input-output-copier:hover {\r\n background-color: #def;\r\n }\r\n\r\n .test-explanation textarea {\r\n width: 100%;\r\n height: 1.5em;\r\n }\r\n\r\n .pending-submission-message {\r\n color: darkorange !important;\r\n }\r\n </style>\r\n <script>\r\n const OPENING_SPACE = String.fromCharCode(1001);\r\n const CLOSING_SPACE = String.fromCharCode(1002);\r\n\r\n const nodeToText = function (node, pre) {\r\n let result = [];\r\n\r\n if (node.tagName === \"SCRIPT\" || node.tagName === \"math\"\r\n || (node.classList && node.classList.contains(\"input-output-copier\")))\r\n return [];\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(OPENING_SPACE);\r\n }\r\n\r\n if (node.nodeType === Node.TEXT_NODE) {\r\n let s = node.textContent;\r\n if (!pre) {\r\n s = s.replace(/\\s+/g, \" \");\r\n }\r\n if (s.length > 0) {\r\n result.push(s);\r\n }\r\n }\r\n\r\n if (pre && node.tagName === \"BR\") {\r\n result.push(\"\\n\");\r\n }\r\n\r\n node.childNodes.forEach(function (child) {\r\n result.push(nodeToText(child, node.tagName === \"PRE\").join(\"\"));\r\n });\r\n\r\n if (node.tagName === \"DIV\"\r\n || node.tagName === \"P\"\r\n || node.tagName === \"PRE\"\r\n || node.tagName === \"UL\"\r\n || node.tagName === \"LI\"\r\n ) {\r\n result.push(\"\\n\");\r\n }\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(CLOSING_SPACE);\r\n }\r\n\r\n return result;\r\n }\r\n\r\n const isSpecial = function (c) {\r\n return c === ',' || c === '.' || c === ';' || c === ')' || c === ' ';\r\n }\r\n\r\n const convertStatementToText = function(statmentNode) {\r\n const text = nodeToText(statmentNode, false).join(\"\").replace(/ +/g, \" \").replace(/\\n\\n+/g, \"\\n\\n\");\r\n let result = [];\r\n for (let i = 0; i < text.length; i++) {\r\n const c = text.charAt(i);\r\n if (c === OPENING_SPACE) {\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"A\" data-uuid=\"ps_843dbea3bbda6da630f9d71dacbddc66c09535a7\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">A. Fox and Number Game</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Fox Ciel is playing a game with numbers now. </p><p>Ciel has <span class=\"tex-span\"><i>n</i></span> positive integers: <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">1</sub></span>, <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">2</sub></span>, ..., <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>n</i></sub></span>. She can do the following operation as many times as needed: select two different indexes <span class=\"tex-span\"><i>i</i></span> and <span class=\"tex-span\"><i>j</i></span> such that <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span> > <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>j</i></sub></span> hold, and then apply assignment <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span> = <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span> - <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>j</i></sub></span>. The goal is to make the sum of all numbers as small as possible.</p><p>Please help Ciel to find this minimal sum.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains an integer <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">2 ≤ <i>n</i> ≤ 100</span>). Then the second line contains <span class=\"tex-span\"><i>n</i></span> integers: <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">1</sub></span>, <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">2</sub></span>, ..., <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>n</i></sub></span> (<span class=\"tex-span\">1 ≤ <i>x</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 100</span>).</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Output a single integer — the required minimal sum.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>2<br />1 2<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>2<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3<br />2 4 6<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>6<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>2<br />12 18<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>12<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>5<br />45 12 27 30 18<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>15<br /></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>In the first example the optimal way is to do the assignment: <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">2</sub></span> = <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">2</sub></span> - <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">1</sub></span>.</p><p>In the second example the optimal sequence of operations is: <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">3</sub></span> = <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">3</sub></span> - <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">2</sub></span>, <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">2</sub></span> = <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">2</sub></span> - <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">1</sub></span>.</p></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=A]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== statementText) {\r\n $problem.find(\".diff-notifier\").show();\r\n\r\n $problem.find(\".diff-notifier-close\").click(function() {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n $problem.find(\".diff-notifier\").hide();\r\n });\r\n\r\n $problem.find(\"a.view-changes\").click(function() {\r\n $.post(\"/data/diff\", {action: \"getDiff\", a: previousStatementText, b: statementText}, function (result) {\r\n if (result[\"success\"] === \"true\") {\r\n Codeforces.facebox(\".diff-popup\", \"//codeforces.org/s/73366\");\r\n $(\"#facebox .diff-popup\").html(result[\"diff\"]);\r\n }\r\n }, \"json\");\r\n });\r\n }\r\n } else {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n }\r\n });\r\n });\r\n </script>\r\n\r\n\r\n<script type=\"text/javascript\">\r\n $(document).ready(function () {\r\n window.changedTests = new Set();\r\n\r\n function endsWith(string, suffix) {\r\n return string.indexOf(suffix, string.length - suffix.length) !== -1;\r\n }\r\n\r\n const inputFileDiv = $(\"div.input-file\");\r\n const inputFile = inputFileDiv.text();\r\n const outputFileDiv = $(\"div.output-file\");\r\n const outputFile = outputFileDiv.text();\r\n\r\n\r\n if (!endsWith(inputFile, \"standard input\")\r\n && !endsWith(inputFile, \"standard input\")) {\r\n inputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n if (!endsWith(outputFile, \"standard output\")\r\n && !endsWith(outputFile, \"standard output\")) {\r\n outputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n const titleDiv = $(\"div.header div.title\");\r\n\r\n\r\n\r\n String.prototype.replaceAll = function (search, replace) {\r\n return this.split(search).join(replace);\r\n };\r\n\r\n $(\".sample-test .title\").each(function () {\r\n const preId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n const cpyId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n\r\n $(this).parent().find(\"pre\").attr(\"id\", preId);\r\n const $copy = $(\"<div title='Copy' data-clipboard-target='#\" + preId + \"' id='\" + cpyId + \"' class='input-output-copier'>Copy</div>\");\r\n $(this).append($copy);\r\n\r\n const clipboard = new Clipboard('#' + cpyId, {\r\n text: function (trigger) {\r\n const pre = document.querySelector('#' + preId);\r\n const lines = pre.querySelectorAll(\".test-example-line\");\r\n return Codeforces.filterClipboardText(pre.innerText, lines.length);\r\n }\r\n });\r\n\r\n const isInput = $(this).parent().hasClass(\"input\");\r\n\r\n clipboard.on('success', function (e) {\r\n if (isInput) {\r\n Codeforces.showMessage(\"The example input has been copied into the clipboard\");\r\n } else {\r\n Codeforces.showMessage(\"The example output has been copied into the clipboard\");\r\n }\r\n e.clearSelection();\r\n });\r\n });\r\n\r\n $(\".test-form-item input\").change(function () {\r\n addPendingSubmissionMessage($($(this).closest(\"form\")), \"You changed the answer, do not forget to submit it if you want to save the changes\");\r\n const index = $(this).closest(\".problemindexholder\").attr(\"problemindex\");\r\n let test = \"\";\r\n $(this).closest(\"form input\").each(function () {\r\n const test_ = $(this).attr(\"name\");\r\n if (test_ && test_.substring(0, 4) === \"test\") {\r\n test = test_;\r\n }\r\n });\r\n if (index.length > 0 && test.length > 0) {\r\n const indexTest = index + \"::\" + test;\r\n window.changedTests.add(indexTest);\r\n }\r\n });\r\n\r\n $(window).on('beforeunload', function () {\r\n if (window.changedTests.size > 0) {\r\n return 'Dialog text here';\r\n }\r\n });\r\n\r\n autosize($('.test-explanation textarea'));\r\n\r\n $(\".test-example-line\").hover(function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n let top = 1E20;\r\n let left = 1E20;\r\n let problem = $(this).closest(\".problemindexholder\");\r\n $(this).closest(\".input\").find(\".\" + clazz).css(\"background-color\", \"#FFFDE7\").each(function() {\r\n top = Math.min(top, $(this).offset().top);\r\n left = Math.min(left, $(this).offset().left);\r\n });\r\n let testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n if (testCaseMarker.length === 0) {\r\n const html = \"<div class=\\\"testCaseMarker testCaseMarker_\" + end + \" notice\\\"></div>\";\r\n problem.append($(html));\r\n testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n }\r\n if (testCaseMarker) {\r\n testCaseMarker.show()\r\n .offset({top, left: left - 20})\r\n .text(end);\r\n }\r\n }\r\n }\r\n });\r\n }, function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n $(\".\" + clazz).css(\"background-color\", \"\");\r\n $(this).closest(\".problemindexholder\").find(\".testCaseMarker_\" + end).hide();\r\n }\r\n }\r\n });\r\n });\r\n\r\n });\r\n</script>\r\n\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 05:38:36</span> (j3).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/73366/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/73366/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/73366/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/73366/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-73366.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'8122c4d4e82315f2',t:'MTY5NjY0NjMxNi40MjcwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"},"long_tags":{"kind":"string","value":"[\"Greedy algorithms\", \"Mathematics including integration, differential equations, etc\"]"},"short_tags":{"kind":"string","value":"[\"greedy\", \"math\", \"*1000\"]"},"tutorial_link":{"kind":"string","value":"https://codeforces.com/blog/entry/10629"},"tutorial_page":{"kind":"string","value":"\r\n\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"74361418aed3add319d25ce966ceafdf\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"h1\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Codeforces Round #228 — Editorial - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n \n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Codeforces Round #228 — Editorial - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/81027/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/81027/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/81027/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/81027/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/81027/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/81027/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/81027/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/81027/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/81027/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/81027/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/81027/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/81027/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/81027/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/81027/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/573cedc6b04c15481941f418269f4057/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='74361418aed3add319d25ce966ceafdf'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/81027/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fblog%2Fentry%2F10629\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='74361418aed3add319d25ce966ceafdf'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Pay attention\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n <div style=\"text-align:center;border-bottom: 1px solid rgb(185, 185, 185);margin:0 -0.5em 0.5em -0.5em;padding: 0 1em 0.5em 1em;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 1, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:51:54</span><br/><a href=\"/contestRegistration/1876\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n <div style=\"text-align:center;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 2, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:51:54</span><br/><a href=\"/contestRegistration/1877\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='74361418aed3add319d25ce966ceafdf'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n </label>\r\n </div>\r\n <div style=\"padding: 0 1em 1em 1em;text-align:right;\">\r\n <input style=\"height:1.65em;padding:0 0.75em;\" type=\"submit\" value=\"Find\"/>\r\n </div>\r\n </form>\r\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".handleBox\").autocomplete(\"/data/handles\", {\r\n delay: 200,\r\n width: 200,\r\n selectFirst: false,\r\n matchContains: true,\r\n minChars: 3\r\n });\r\n $(\".handleForm\").attr(\"autocomplete\", \"off\").submit(function () {\r\n var link = \"/profile/userHandle\".replace(\r\n \"userHandle\", $(this).find(\".handleBox\").val()\r\n );\r\n window.location = link;\r\n return false;\r\n });\r\n });\n </script>\n\r\n\r\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Recent actions\n <div class=\"top-links\">\n </div>\n </div>\n <div class=\"recent-actions\">\r\n <ul>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/121073\">Meta Hacker Cup 2023 Round 1</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/.Danet\" title=\"Expert .Danet\" class=\"rated-user user-blue\">.Danet</a> →\r\n <a href=\"/blog/entry/121172\">[TLE on pretest1]</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\" class=\"rated-user user-red\">Pyqe</a> →\r\n <a href=\"/blog/entry/121025\">Codeforces Round #902 (Div. 1, Div. 2, based on COMPFEST 15 — Final Round)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pranshu_Pandya\" title=\"Specialist Pranshu_Pandya\" class=\"rated-user user-cyan\">Pranshu_Pandya</a> →\r\n <a href=\"/blog/entry/121171\">An Interesting Tree Problem</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/sszcdjr\" title=\"Master sszcdjr\" class=\"rated-user user-orange\">sszcdjr</a> →\r\n <a href=\"/blog/entry/119859\">Codeforces Round 896 (Div. 1, Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/119880\">It's Happening! Meta Hacker Cup 2023 Schedule</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/DaviddeGea1\" title=\"Expert DaviddeGea1\" class=\"rated-user user-blue\">DaviddeGea1</a> →\r\n <a href=\"/blog/entry/70917\">Number of ways of dividing an array into 2 parts such that sum of each part is > k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bekh\" title=\"Master Bekh\" class=\"rated-user user-orange\">Bekh</a> →\r\n <a href=\"/blog/entry/74245\">Questions and doubts regarding Aliens DP trick</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a> →\r\n <a href=\"/blog/entry/8192\">Codeforces Round #190 — Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/hocky\" title=\"Candidate Master hocky\" class=\"rated-user user-violet\">hocky</a> →\r\n <a href=\"/blog/entry/95323\">FBHC wuining uw Day? Incwease uw stacc size! (ㅅ´ ˘ `)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/liouzhou_101\" title=\"International Master liouzhou_101\" class=\"rated-user user-orange\">liouzhou_101</a> →\r\n <a href=\"/blog/entry/87598\">Editorial of Codeforces Round #700</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/yeon_gist\" title=\"Newbie yeon_gist\" class=\"rated-user user-gray\">yeon_gist</a> →\r\n <a href=\"/blog/entry/121170\">plusMinusPermutation computing error</a>\r\n <img alt=\"Text created or updated\" title=\"Text created or updated\" src=\"//codeforces.org/s/81027/images/icons/x-update-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/altforminuscontribution\" title=\"Newbie altforminuscontribution\" class=\"rated-user user-gray\">altforminuscontribution</a> →\r\n <a href=\"/blog/entry/121162\">My screen get unexpectedly big, what should I do</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/atcoder_official\" title=\"Unrated, atcoder_official\" class=\"rated-user user-black\">atcoder_official</a> →\r\n <a href=\"/blog/entry/121120\">We will hold UNIQUE VISION Programming Contest 2023 Autumn(AtCoder Beginner Contest 323)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/YouStill_DontKnowMeYet\" title=\"Candidate Master YouStill_DontKnowMeYet\" class=\"rated-user user-violet\">YouStill_DontKnowMeYet</a> →\r\n <a href=\"/blog/entry/117659\">[GYM] Al-Baath Collegiate Programming Contest 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/ankancool\" title=\"Expert ankancool\" class=\"rated-user user-blue\">ankancool</a> →\r\n <a href=\"/blog/entry/121136\">Invitation to AstroByte 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/GeZhiyuan\" title=\"Grandmaster GeZhiyuan\" class=\"rated-user user-red\">GeZhiyuan</a> →\r\n <a href=\"/blog/entry/120943\">Codeforces Round 901 (Div. 1, Div. 2) Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a> →\r\n <a href=\"/blog/entry/120772\">PSA: Increase your stack size before the Meta Hacker Cup, here's how</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/dino_merlin\" title=\"Expert dino_merlin\" class=\"rated-user user-blue\">dino_merlin</a> →\r\n <a href=\"/blog/entry/121145\">Intuitive approach for CEOI Kangaroo?</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/icecuber\" title=\"Grandmaster icecuber\" class=\"rated-user user-red\">icecuber</a> →\r\n <a href=\"/blog/entry/70018\">CSES DP section editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bn00b\" title=\"Newbie Bn00b\" class=\"rated-user user-gray\">Bn00b</a> →\r\n <a href=\"/blog/entry/98820\">[FEATURE REQUEST : ATCODER] TOPICS TAGS AND SORTING BY SOLVE COUNT</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a> →\r\n <a href=\"/blog/entry/121163\">AtCoder Regular Contest 166 Announcement</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/windva\" title=\"Grandmaster windva\" class=\"rated-user user-red\">windva</a> →\r\n <a href=\"/blog/entry/120644\">Codeforces Round 899 (Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Misa-Misa\" title=\"Expert Misa-Misa\" class=\"rated-user user-blue\">Misa-Misa</a> →\r\n <a href=\"/blog/entry/121157\">Someone please help me understand this.</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/shivam565\" title=\"Specialist shivam565\" class=\"rated-user user-cyan\">shivam565</a> →\r\n <a href=\"/blog/entry/108348\">Total number of subarrays with sum atmost k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n </ul>\r\n </div>\r\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/recent-actions\">Detailed →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n</div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li><a\r\n href=\"/profile/cgy4ever\">cgy4ever</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/cgy4ever\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/cgy4ever\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/cgy4ever\">Submissions</a></li>\r\n <li><a\r\n href=\"/groups/with/cgy4ever\">Groups</a></li>\r\n <li><a\r\n href=\"/contests/with/cgy4ever\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/cgy4ever\">Problemsetting</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/cgy4ever\" style=\"text-decoration:none;color:black !important;\">cgy4ever's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"10684\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/10629\"> <p>Codeforces Round #228 — Editorial</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a>,\r\n <span class=\"format-humantime\" title=\"Feb/03/2014 22:14\">10 years ago</span>,\r\n \r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p>You can find the editorial and my solutions here: <a href=\"https://github.com/cgy4ever/CF228\">https://github.com/cgy4ever/CF228</a></p><p><a href=\"/contest/389/problem/A\" title=\"Codeforces Round 228 (Div. 2)\">389A - Fox and Number Game</a></p><p>First we know that: in the optimal solution, all number will be equal: otherwise we can pick a and b (a < b) then do b = b — a, it will make the answer better.</p><p>Then we need an observation: after each operation, the GCD (Greatest common divisor) of all number will remain same. It can be proved by this lemma: if g is a divisor of all number of x[], then after the operation, g is still the divisor of these numbers, and vice versa.</p><p>So in the end, all number will become the GCD of x[].</p><p>Another solution that can pass is: While there exist x[i] > x[j], then do x[i] -= x[j]. We can select arbitrary i and j if there exist more than 1 choice.</p><p><a href=\"/contest/389/problem/B\" title=\"Codeforces Round 228 (Div. 2)\">389B - Fox and Cross</a></p><p>Let's define the first # of a shape is the cell contain # that have the lexicographical smallest coordinate. Then the first # of a cross is the top one.</p><p>Then let x be the first # of the given board. (If the board is empty, then we can draw it with zero crosses.) x must be covered by a cross, and x must be the first # of the cross. (You can try 4 other positions, it will cause a lexicographical smaller # in the board than x)</p><p>So we try to cover this x use one cross, if it leads some part of the cross covers a '.', then there will be no solution. If not, we just reduce the number of # in the board by 4, we can do this again and again.</p><p><a href=\"/contest/389/problem/C\" title=\"Codeforces Round 228 (Div. 2)\">389C - Fox and Box Accumulation</a> / <a href=\"/contest/388/problem/A\" title=\"Codeforces Round 228 (Div. 1)\">388A - Fox and Box Accumulation</a></p><p>We need some observation:</p> <ol> <li><p>There exists an optimal solution such that: in any pile, the box on the higher position will have a smaller strength.</p></li> <li><p>Let k be the minimal number of piles, then there exists an optimal solution such that: The height of all piles is n/k or n/k+1 (if n%k=0, then all of them have the height n/k).</p></li> </ol><p>We can prove them by exchange argument: from an optimal solution, swap the boxes in it to make above property holds, and we can ensure it will remain valid while swapping.</p><p>Then for a given k, we can check whether there exist a solution: the i-th (indexed from 0) smallest strength needs to be at least i/k.</p><p>So we can do binary search (or just enumerate, since n is only 100) on k.</p><p><a href=\"/contest/389/problem/D\" title=\"Codeforces Round 228 (Div. 2)\">389D - Fox and Minimal path</a> / <a href=\"/contest/388/problem/B\" title=\"Codeforces Round 228 (Div. 1)\">388B - Fox and Minimal path</a></p><p>First we need to know how to calculate the number of different shortest paths from vertex 1 to vertex 2: it can be done by dp: dp[1] = 1, dp[v] = sum{dp[t] | dist(1,t) = dist(1,v) — 1}, then dp[2] is our answer.</p><p>We need to do dp layer by layer. (first we consider vertexes have distance 1 to node 1, then vertexes have distance 2 to node 1 and so on.) So we can construct the graph layer by layer, and link edges to control the dp value of it.</p><p>My solution is construct the answer by binary express: If k is 19, then we need some vertexes in previous layer such that the dp value is 16, 2 and 1. So we just need a way to construct layer with dp value equals to 2^k.</p><p>In the first layer, it contains one node: 1, it has the dp value 1. In the next layer, we can construct 2 nodes, with dp value equals to 1. (We use [1 1] to denote it). And the next layer is [1 1 2], then [1 1 2 4], [1 1 2 4 8] and so on. So we need about 30 layers such that gets all 2^k where k < 30. It uses about 500 nodes.</p><p><a href=\"/contest/389/problem/E\" title=\"Codeforces Round 228 (Div. 2)\">389E - Fox and Card Game</a> / <a href=\"/contest/388/problem/C\" title=\"Codeforces Round 228 (Div. 1)\">388C - Fox and Card Game</a></p><p>First let's consider the case which all piles have even size. In this case, we can prove: in the optimal play, Ciel will gets all top most half cards of each pile, and Jiro gets the remain cards.</p><p>We can prove by these facts: Ciel have a strategy to ensure she can get this outcome and Jiro also have a strategy to ensure this outcome. (For Jiro this strategy is easy: just pick the card from pile that Ciel have just picked. For Ciel it's a little bit harder.)</p><p>Why we can conclude they are both the optimal strategy? Ciel just can't win more, because if she played with Jiro with above strategy, Jiro will get the bottom half of each pile.</p><p>Then we come back with cases that contain odd size piles. The result is: for odd size pile, Ciel will get the top (s-1)/2 cards and Jiro will get the bottom (s-1)/2 cards. Then what about the middle one? Let's denote S is all such middle cards. Then we define a reduced game: In each turn, they pick one card from S. The optimal play for this game is easy: Ciel gets the max one, and Jiro gets the 2nd largest one, and Ciel gets the 3rd largest one and so on.</p><p>We can prove Ciel have a strategy to get: all top half parts + cards she will get in the optimal play in the reduced game. And Jiro also have a strategy to get: all bottom half parts + cards he will get in the optimal play in the reduced game. And these strategy are optimal.</p><p><a href=\"/contest/388/problem/D\" title=\"Codeforces Round 228 (Div. 1)\">388D - Fox and Perfect Sets</a></p><p>A perfect set correspond to a linear space, so we can use base to represent it. We do the Gauss–Jordan elimination of vectors in that set, and can get an unique base. (Note that we need to to the all process of Gauss–Jordan elimination, including the elimination after it reached upper triangular)</p><p>And we can construct the bases bit by bit from higher bit to lower, for a bit:</p> <ol> <li><p>We can add a vector to the base such that the bit is the highest bit of that vector. And at this time, all other vector will have 0 in this bit.</p></li> <li><p>Otherwise we need to assign this bit of each vector already in the base. If now we have k vector, then we have 2^k choices.</p></li> </ol><p>And when we do this, we need to know what's the maximal vector in this space. It's not hard:</p> <ol> <li><p>If we add a vector, then in the maximal vector, this bit will be 1.</p></li> <li><p>Otherwise, if we don't have any vector in base yet, then this bit will be 0. Otherwise there will be 2^(k-1) choices results in this bit of maximal vector will be 0, and 2^(k-1) choices results in 1.</p></li> </ol><p>So we can solve this task by DP bit by bit.</p><p><a href=\"/contest/388/problem/E\" title=\"Codeforces Round 228 (Div. 1)\">388E - Fox and Meteor Shower</a></p><p>All tasks beside this are very easy to code. And this one focus on implementation.</p><p>We can represent the orbit of each meteor by a line in 3D space. (we use an axis to represent the time, and two axis to represent the position on the plane.)</p><p>Then the problem becomes: we have some lines in 3D space (they are not complete coincide), find a largest clique such that each pair of lines touch at some point.</p><p>We need this observation: If there are 3 lines in the optimal clique, and these 3 lines are not share a common point, then all line in this clique will on a plane.</p><p>By using this observation, we only need to consider 2 cases:</p> <ol> <li><p>All lines in the clique have a common point.</p></li> <li><p>All lines in the clique are on the same plane.</p></li> </ol><p>Both are easy tasks in theory, but it needs some coding.</p><p>There are two ways:</p> <ol> <li><p>Use integer anywhere. Note that the coordinates of intersection can be rational number, but can't be irrational, so we could do this. We can use some way to encode the plane, direction.</p></li> <li><p>Use floating number. To count same number of points, we can sort (x, y, z) by using the following compare function: if (abs(A.x — B.x) > eps){return A.x < B.x} otherwise { if(abs(A.y-B.y)>eps){return A.y < B.y} otherwise return A.z < B.z}.</p></li> </ol></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/388\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 228 (Div. 1)</a> </span>\r\n </div>\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/389\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 228 (Div. 2)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-21-10684\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"21\",\n blogEntryId: \"10629\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-10684\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+45</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-10684\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/cgy4ever\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/cgy4ever\">\n cgy4ever\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Feb/03/2014 22:14\">10 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/10629#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/10629#comments\">\n 44\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"10700\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (39)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159842\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/YaleZ\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/24526/avatar/5b17db1affad55a5.jpg'/> </a>\n <div><a href=\"/profile/YaleZ\" title=\"Expert YaleZ\" class=\"rated-user user-blue\">YaleZ</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2014 22:38\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159842\" href=\"?#comment-159842\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"159842\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"159842\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"24526\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159842\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thank for timely editorial. I think Markdown is better when publish something on Github. Isn't it?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159842 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159842 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159842\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159846\" commentParentId=\"159842\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/cgy4ever\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2014 22:43\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159846\" href=\"?#comment-159846\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159842\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159846\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"11\"\r\n data-commentUserId=\"62\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+11</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159846\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Yes, I'm working on it. :)</p><p>The website seems to be not stable at this time. So I post them in other sites to ensure all people can see it.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159846 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159846 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159846\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159857\" commentParentId=\"159846\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Nodir.Daminov\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/71439/avatar/d6d2016f6dfe5ecd.jpg'/> </a>\n <div><a href=\"/profile/Nodir.Daminov\" title=\"Candidate Master Nodir.Daminov\" class=\"rated-user user-violet\">Nodir.Daminov</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2014 22:58\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159857\" href=\"?#comment-159857\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159846\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159857\" class=\"CommentVoteFrame\"\r\n class=\"too-negative-comment-vote\"\r\n data-commentRating=\"-35\"\r\n data-commentUserId=\"71439\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-35</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159857\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Maaan is it so hard to COPY ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159857 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159857 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159857\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159874\" commentParentId=\"159857\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/cgy4ever\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2014 23:19\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159874\" href=\"?#comment-159874\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159857\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159874\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"12\"\r\n data-commentUserId=\"62\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+12</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159874\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Sorry for the delay.</p><p>When I was submitting my post that contains the editorial, it always returns "Codeforces is now unavailable." so I just can't post it.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159874 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159874 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159874\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159859\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/BishalG\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/60637/avatar/d21ddf49bbd1630c.jpg'/> </a>\n <div><a href=\"/profile/BishalG\" title=\"Expert BishalG\" class=\"rated-user user-blue\">BishalG</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2014 22:58\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159859\" href=\"?#comment-159859\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159859\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"60637\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159859\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Nice problemSets @<a class=\"rated-user user-orange\" href=\"/profile/cgy4ever\" title=\"International Master cgy4ever\">cgy4ever</a> , although I misunderstood the problem-B <a href=\"/contest/389/problem/B\" title=\"Codeforces Round 228 (Div. 2)\">389B - Fox and Cross</a> upto 1 hrs :( </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159859 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159859 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159859\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159867\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Mr.ink\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Mr.ink\" title=\"Expert Mr.ink\" class=\"rated-user user-blue\">Mr.ink</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2014 23:07\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159867\" href=\"?#comment-159867\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159867\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"128876\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159867\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>due to my slow internet speed i can not see your editorial on github because my country internet has problem with https! </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159867 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159867 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159867\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159881\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Mr.ink\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Mr.ink\" title=\"Expert Mr.ink\" class=\"rated-user user-blue\">Mr.ink</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2014 23:38\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159881\" href=\"?#comment-159881\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159881\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"128876\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159881\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>does anyone have a better solution for div2 C problem?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159881 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159881 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159881\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159883\" commentParentId=\"159881\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/t_thirupathi\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/146179/avatar/98c28348196ce4ca.jpg'/> </a>\n <div><a href=\"/profile/t_thirupathi\" title=\"Specialist t_thirupathi\" class=\"rated-user user-cyan\">t_thirupathi</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2014 23:42\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159883\" href=\"?#comment-159883\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159881\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159883\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"146179\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159883\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Have a look at mine <a href=\"/contest/389/submission/5878414\" title=\"Submission 5878414 by t_thirupathi\">5878414</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159883 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159883 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159883\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159909\" commentParentId=\"159883\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/9charles\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/119814/avatar/653156a3153bc2dd.jpg'/> </a>\n <div><a href=\"/profile/9charles\" title=\"Expert 9charles\" class=\"rated-user user-blue\">9charles</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 06:46\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159909\" href=\"?#comment-159909\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159883\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159909\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"119814\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159909\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can you explain it?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159909 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159909 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159909\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159907\" commentParentId=\"159881\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/k790alex\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/119882/avatar/4baeddca65b2b958.jpg'/> </a>\n <div><a href=\"/profile/k790alex\" title=\"Specialist k790alex\" class=\"rated-user user-cyan\">k790alex</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 06:28\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159907\" href=\"?#comment-159907\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159881\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159907\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"119882\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159907\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I don't know if this is a better way but I didt in the contest.</p><p>Start making a pile with the low strength and while possible, look for a box that can support at least 1 box, then at least 2 boxes, 3, etc, repeat it while you have boxes.</p><p>My solution: <a href=\"/contest/389/submission/5879464\" title=\"Submission 5879464 by k790alex\">5879464</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159907 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159907 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159907\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159914\" commentParentId=\"159907\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/YaleZ\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/24526/avatar/5b17db1affad55a5.jpg'/> </a>\n <div><a href=\"/profile/YaleZ\" title=\"Expert YaleZ\" class=\"rated-user user-blue\">YaleZ</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 07:38\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159914\" href=\"?#comment-159914\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159907\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159914\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"24526\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159914\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Greedy is also a nice solution.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159914 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159914 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159914\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159932\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/worfzyq\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/157364/avatar/8f104a361ed91be8.jpg'/> </a>\n <div><a href=\"/profile/worfzyq\" title=\"Expert worfzyq\" class=\"rated-user user-blue\">worfzyq</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 09:52\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159932\" href=\"?#comment-159932\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159932\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"157364\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159932\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>388C — Fox and Card Game This problem is good magic</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159932 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159932 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159932\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159935\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/orchidmajumder\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/63603/avatar/f8db3747466a7168.jpg'/> </a>\n <div><a href=\"/profile/orchidmajumder\" title=\"Specialist orchidmajumder\" class=\"rated-user user-cyan\">orchidmajumder</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 10:07\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159935\" href=\"?#comment-159935\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"159935\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"159935\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"7\"\r\n data-commentUserId=\"63603\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+7</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159935\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>hii everyone,in Div II E,I can't understand why the optimal play for JIRO is to take the bottom most card from the same pile from where CIEL is picking?should not it try to pick the maximum value among all bottom most card at it's every move??</p><p>Please someone explain why the strategy presented in the editorial is optimal.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159935 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159935 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159935\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159948\" commentParentId=\"159935\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Zzyzx\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/86049/avatar/c698ee674460e7eb.jpg'/> </a>\n <div><a href=\"/profile/Zzyzx\" title=\"Expert Zzyzx\" class=\"rated-user user-blue\">Zzyzx</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 13:07\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159948\" href=\"?#comment-159948\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159935\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159948\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"86049\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159948\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Ok, I'm afraid I do not have a rigorous proof for this. I'll just explain to you why I think it is right.</p><p>First of all, we need to understand that both Ciel and Jiro are smart. Now, whenever it is Ciel's turn, he will pick the "best pile" and try to take everything from that pile and then move on to the next "best pile". Jiro knows that his friend Ciel is smart, so he will try to stop him from taking everything. This can be done only if he picks from the same pile that Ciel does.</p><p>But your question is — what if there is a different pile whose bottom-most card is much better than the bottom-most card of the pile from which Ciel is picking right?</p><p>My answer to this is that, this situation will never arise. Because if there is such a pile, then Ciel will try to take that card in the first place and therefore, Ciel will be picking from the same pile that Jiro will want to pick from.</p><p>Am I making sense? Or is there a flaw in my argument?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159948 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159948 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159948\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159952\" commentParentId=\"159948\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/orchidmajumder\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/63603/avatar/f8db3747466a7168.jpg'/> </a>\n <div><a href=\"/profile/orchidmajumder\" title=\"Specialist orchidmajumder\" class=\"rated-user user-cyan\">orchidmajumder</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 13:32\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159952\" href=\"?#comment-159952\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159948\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159952\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"63603\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159952\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Yes I'm also thinking along the same line.Both are playing optimally and if Ciel is chosing any pile then jiro knows that this pile has better cards in the botttom half.So he won't choose ciel to take the advantage and vice versa.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159952 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159952 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159952\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159944\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hzyfr\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/hzyfr\" title=\"Expert hzyfr\" class=\"rated-user user-blue\">hzyfr</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 12:27\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159944\" href=\"?#comment-159944\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159944\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"129936\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159944\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I have a different idea on D div1 <a href=\"/contest/388/problem/D\" title=\"Codeforces Round 228 (Div. 1)\">388D - Fox and Perfect Sets</a> but I failed on getting some relations in one step.</p><p>Let <em>M</em> be the maximum element in set <em>S</em> . Then if <em>S</em> is a perfect set, its elements should have all bits equals <em>0</em> on positions in <em>M's</em> binary representation(otherwise there must exist another element bigger than <em>M</em>). So let <em>cnt</em> = (number of 1's in binary repersentation of <em>M</em>), then the number of perfect sets which has <em>M</em> as its greatest element is determined by <em>cnt</em> . Well, this is the step I can't come up with a solution(actually the target is to find the number of perfect sets which has <code>2^cnt-1</code> as its greatest element).</p><p>Then the last step is simple. We can apply something like doubling algorithm on the problem.</p><p>We are asked to find the number of perfect sets with all the elements not greater than <em>N</em> . Let's suppose <em>N+1</em> is a power of 2 then its easy to calculate how many numbers not greater than <em>N</em> has <em>cnt</em> = 1,2,...m where m is the length of <em>N</em> in binary representation. That's just simple combinatoric number <em>C(n,i) (1<=i<=n)</em> . And if we have done the previous step, it's easy to get the result.</p><p>Then think about common cases of <em>N</em> . Let's take the highest bit of N and since all above bits are determined, the number of 1's will just add a constant value. So calculate this part and subtract that highest bit of <em>N</em> and do the same thing on remaining value of <em>N</em> , until <em>N=0</em> . At that time we will get the correct answer. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159944 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159944 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159944\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159945\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/rexdf\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/23738/avatar/797fa665fbe1ca78.jpg'/> </a>\n <div><a href=\"/profile/rexdf\" title=\"Specialist rexdf\" class=\"rated-user user-cyan\">rexdf</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 12:36\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159945\" href=\"?#comment-159945\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159945\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"23738\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159945\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>dp[1] = 1, dp[v] = sum{dp[t] | dist(1,t) = dist(1,v) — 1}, then dp[2] is our answer. What's v means? what's '|' means? What's dp[v] means?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159945 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159945 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159945\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159949\" commentParentId=\"159945\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/sancho\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/85894/avatar/e31a4b24327c1000.jpg'/> </a>\n <div><a href=\"/profile/sancho\" title=\"Candidate Master sancho\" class=\"rated-user user-violet\">sancho</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 13:10\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159949\" href=\"?#comment-159949\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159945\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159949\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"85894\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159949\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>v — vertex, answer for which we are getting at this moment, | — means "such as", dp[v] — number of ways from 1 vertex to this one</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159949 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159949 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159949\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159947\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lol12\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/lol12\" title=\"Specialist lol12\" class=\"rated-user user-cyan\">lol12</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 13:04\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159947\" href=\"?#comment-159947\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159947\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"10\"\r\n data-commentUserId=\"152356\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+10</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159947\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can someone please explain solution of Div2-D. Thanx</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159947 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159947 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159947\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"160020\" commentParentId=\"159947\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/YaleZ\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/24526/avatar/5b17db1affad55a5.jpg'/> </a>\n <div><a href=\"/profile/YaleZ\" title=\"Expert YaleZ\" class=\"rated-user user-blue\">YaleZ</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/05/2014 07:07\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-160020\" href=\"?#comment-160020\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159947\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"160020\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"9\"\r\n data-commentUserId=\"24526\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+9</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-160020\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>You can think about binnary. Such as (13)10=(1101)2=((1+(2+0)*2)+1)*2+1</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-160020 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-160020 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-160020\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"469976\" commentParentId=\"159947\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/roll_no_1\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/631859/avatar/36d157f91f64fe7f.jpg'/> </a>\n <div><a href=\"/profile/roll_no_1\" title=\"Master roll_no_1\" class=\"rated-user user-orange\">roll_no_1</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Nov/09/2018 17:27\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-469976\" href=\"?#comment-469976\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159947\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"469976\" revisionCount=\"4\" revision=\"4\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">4</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"469976\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"631859\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-469976\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Here's my implementation of the editorialist's explanation of Div-2 D / Div-1 B: <a href=\"/contest/388/submission/45480077\" title=\"Submission 45480077 by roll_no_1\">45480077</a>. I implemented the layers as [1], [1, 1], [2, 1, 1], [4, 2, 1, 1] and so on.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-469976 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-469976 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-469976\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159967\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/BENYAM1N\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/84938/avatar/d2ae2657d8898e38.jpg'/> </a>\n <div><a href=\"/profile/BENYAM1N\" title=\"Master BENYAM1N\" class=\"rated-user user-orange\">BENYAM1N</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 15:51\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159967\" href=\"?#comment-159967\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159967\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"13\"\r\n data-commentUserId=\"84938\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+13</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159967\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Very good contest and nice editorial. Hope from now on I see more contests from you.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159967 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159967 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159967\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159984\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/kojak_\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/57722/avatar/38990eea59bc188e.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/kojak_\" title=\"Newbie kojak_\" class=\"rated-user user-gray\">kojak_</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 18:34\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159984\" href=\"?#comment-159984\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159984\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"57722\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159984\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Did anyone come up with a DP solution for Div.2 C/ Div.1 A?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159984 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159984 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159984\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"160012\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/IgorKoval\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/51322/avatar/afc854fff49f072a.jpg'/> </a>\n <div><a href=\"/profile/IgorKoval\" title=\"Candidate Master IgorKoval\" class=\"rated-user user-violet\">IgorKoval</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 23:17\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-160012\" href=\"?#comment-160012\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"160012\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"11\"\r\n data-commentUserId=\"51322\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+11</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-160012\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Объясните, пожалуйста, разбор задачи "388D — Fox and Perfect Sets" на пальцах. Как-нибудь без Гаусса и базисов. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-160012 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-160012 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-160012\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"160016\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Mr.ink\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Mr.ink\" title=\"Expert Mr.ink\" class=\"rated-user user-blue\">Mr.ink</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/05/2014 01:08\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-160016\" href=\"?#comment-160016\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"160016\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"128876\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-160016\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>fox and card games is a great problem.thanks!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-160016 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-160016 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-160016\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"160037\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/yaswanth\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/yaswanth\" title=\"Specialist yaswanth\" class=\"rated-user user-cyan\">yaswanth</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/05/2014 18:38\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-160037\" href=\"?#comment-160037\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"160037\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"9\"\r\n data-commentUserId=\"96196\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+9</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-160037\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can anyone explain div2 C question? I did not understand the editorial.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-160037 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-160037 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-160037\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"160063\" commentParentId=\"160037\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/YaleZ\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/24526/avatar/5b17db1affad55a5.jpg'/> </a>\n <div><a href=\"/profile/YaleZ\" title=\"Expert YaleZ\" class=\"rated-user user-blue\">YaleZ</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/06/2014 05:46\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-160063\" href=\"?#comment-160063\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-160037\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"160063\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"24526\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-160063\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>s[i]>=i/k -> k*s[i]>=i There are i boxes' strength smaller than i-th box. So we need to check if the boxes before i-th can be held.</p><p>(I don't know whether I have understood correctly...)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-160063 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-160063 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-160063\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"160053\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/yada\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/142663/avatar/49901b54d1c5f019.jpg'/> </a>\n <div><a href=\"/profile/yada\" title=\"Candidate Master yada\" class=\"rated-user user-violet\">yada</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/05/2014 23:24\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-160053\" href=\"?#comment-160053\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"160053\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"142663\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-160053\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Great Problem! I really enjoy it.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-160053 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-160053 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-160053\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"364019\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lnzva\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/305672/avatar/cf6c09a214141751.jpg'/> </a>\n <div><a href=\"/profile/lnzva\" title=\"Expert lnzva\" class=\"rated-user user-blue\">lnzva</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/02/2017 22:06\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-364019\" href=\"?#comment-364019\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"364019\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"364019\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"305672\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-364019\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In 388C, I'm having a hard time understanding why Jiro's optimal strategy would be to pick the pile Ciel just picked. Why not pick a pile which has a better bottom part than the one Ciel is picking? According to some comments, Ciel would then pick from the second pile-what if another pile has a much better top part? Could someone please help? I saw this problem first 6 months ago, and I had a hard time understanding why this greedy is correct; I saw this problem again today and am having trouble with it again, with no progress.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-364019 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-364019 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-364019\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"647866\" commentParentId=\"364019\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/_wzx27\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1458283/avatar/7d77b62012ae2398.jpg'/> </a>\n <div><a href=\"/profile/_wzx27\" title=\"Candidate Master _wzx27\" class=\"rated-user user-violet\">_wzx27</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/22/2020 18:33\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-647866\" href=\"?#comment-647866\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-364019\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"647866\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1458283\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-647866\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Let's consider such a two-piles situation:</p><p><em>111100</em></p><p><em>001111</em></p><p>is better for Ciel.</p><p>"1" means this card is picked by Ciel,while "0" by Jiro.</p><p>We know that better for Ciel means worse for Jiro.</p><p>So if</p><p><em>111100</em></p><p><em>001111</em></p><p>is better than</p><p><em>111000</em></p><p><em>000111</em></p><p>for Ciel.</p><p>Then when Ciel picked the <strong>first three cards</strong> from <strong>pile 1</strong>,Jiro can just pick the <strong>last three cards</strong> from <strong>pile 1</strong> and finally lead to the result:</p><p><em>111000</em></p><p><em>000111</em></p><p>which is not better for Ciel.</p><p>Generally, if the final result is not balance(half from top and half from bottom) while balance is better than such result for Jiro, Jiro has the ability to adjust it to be balance.So do Ciel.</p><p>Therefore,it reaches balance.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-647866 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-647866 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-647866\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"407776\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/madhur4127\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/568692/avatar/c7d62cc23c758819.jpg'/> </a>\n <div><a href=\"/profile/madhur4127\" title=\"Specialist madhur4127\" class=\"rated-user user-cyan\">madhur4127</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/15/2018 13:06\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-407776\" href=\"?#comment-407776\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"407776\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"568692\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-407776\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>@<a class=\"rated-user user-red\" href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\">cgy4ever</a>, github link shows 404 error(Page not found). Kindly fix it.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-407776 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-407776 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-407776\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"416354\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/introverted\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/657339/avatar/7a6edb1ecc1d3e09.jpg'/> </a>\n <div><a href=\"/profile/introverted\" title=\"Expert introverted\" class=\"rated-user user-blue\">introverted</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/23/2018 11:48\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-416354\" href=\"?#comment-416354\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"416354\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"657339\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-416354\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I solved the DIV1B problem with simple recursion and Divide and Conquer.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-416354 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-416354 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-416354\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"427890\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Nuu\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/652228/avatar/d59867d6477379dc.jpg'/> </a>\n <div><a href=\"/profile/Nuu\" title=\"Candidate Master Nuu\" class=\"rated-user user-violet\">Nuu</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/01/2018 22:33\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-427890\" href=\"?#comment-427890\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"427890\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"652228\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-427890\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can anyone give me some examples of the similar problems to DivC?? I think this problem is very nice for train brain xD</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-427890 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-427890 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-427890\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"629609\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/The_Alchemist\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1275181/avatar/662970aa05d3dfc5.jpg'/> </a>\n <div><a href=\"/profile/The_Alchemist\" title=\"Expert The_Alchemist\" class=\"rated-user user-blue\">The_Alchemist</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/25/2020 21:47\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-629609\" href=\"?#comment-629609\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"629609\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1275181\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-629609\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I know I am very late but can someone pls explain to me div 2C/div1A. Thanks in advance... </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-629609 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-629609 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-629609\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"641010\" commentParentId=\"629609\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/kstheking\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1160931/avatar/e144fc7b0fdb90b1.jpg'/> </a>\n <div><a href=\"/profile/kstheking\" title=\"Pupil kstheking\" class=\"rated-user user-green\">kstheking</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/13/2020 14:47\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-641010\" href=\"?#comment-641010\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-629609\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"641010\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1160931\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-641010\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p><a href=\"https://codeforces.com/contest/388/submission/83605110\">https://codeforces.com/contest/388/submission/83605110</a> Here you go, if you don't get it feel free to ask</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-641010 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-641010 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-641010\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"644488\" commentParentId=\"641010\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/tanisha_\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/tanisha_\" title=\"Newbie tanisha_\" class=\"rated-user user-gray\">tanisha_</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/18/2020 15:26\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-644488\" href=\"?#comment-644488\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-641010\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"644488\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1500127\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-644488\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>is this any algorithm</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-644488 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-644488 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-644488\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"647627\" commentParentId=\"644488\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/kstheking\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1160931/avatar/e144fc7b0fdb90b1.jpg'/> </a>\n <div><a href=\"/profile/kstheking\" title=\"Pupil kstheking\" class=\"rated-user user-green\">kstheking</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/22/2020 08:40\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-647627\" href=\"?#comment-647627\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-644488\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"647627\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"647627\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1160931\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-647627\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Well you can call it a greedy algorithm, when we try to apply greedy by placing the heaviest block in bottom, a little problem occurs because of blocks of same strength for example in case of 10 2 2 1 1 0 0<br />If you try to apply greedy by choosing the strongest block<br />10 2 2 1<br />1 0<br />0<br />= 3 heaps<br />Which is wrong answer as sometimes we lose opportunity to create lesser heaps, as in this case if we use the second 2 to make another heap we can do better<br />10 2 1 0<br />2 1 0<br />= 2 heaps<br />So I apply greedy in the reverse direction by picking the smallest strength brick and placing below it the next smallest brick, this way the optimal number of heaps will be formed as in above example<br />choose 0, then you need >= 1, choose 1, then you need >= 2, choose 2, then you need >= 3 choose 10<br />repeat until you have chosen all the bricks<br />If you don't get anything, feel free to ask :) </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-647627 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-647627 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-647627\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"702677\" commentParentId=\"647627\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/breddreamer\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/853067/avatar/240684624b57996.jpg'/> </a>\n <div><a href=\"/profile/breddreamer\" title=\"Newbie breddreamer\" class=\"rated-user user-gray\">breddreamer</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/27/2020 13:01\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-702677\" href=\"?#comment-702677\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-647627\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"702677\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"853067\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-702677\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks, It helped me to understand your solution idea. And finally, I solved this one.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-702677 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-702677 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-702677\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"649225\" commentParentId=\"641010\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/The_Alchemist\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1275181/avatar/662970aa05d3dfc5.jpg'/> </a>\n <div><a href=\"/profile/The_Alchemist\" title=\"Expert The_Alchemist\" class=\"rated-user user-blue\">The_Alchemist</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/24/2020 12:04\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-649225\" href=\"?#comment-649225\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-641010\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"649225\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1275181\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-649225\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>thank you.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-649225 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-649225 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-649225\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n <br/>\r\n\r\n<div id=\"editBox-10700\" style=\"width:50em;display:none;\">\r\n <div class=\"previewBody\" style=\"border: 1px solid #d4d4d4; margin-bottom: 0.5em; padding: 0.25em; display:none;\"> </div>\r\n <div style=\"width: 1px\"> </div>\r\n <div class=\"commentLocale\" style=\"position: relative; top: 0.5em;left:4px;display: none;\">\r\n <input type=\"radio\" name=\"locale\" value=\"en\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In English</span>\r\n <input style=\"margin-left:1em\" type=\"radio\" name=\"locale\" value=\"ru\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In Russian</span>\r\n </div>\r\n <textarea data-drafts-id=\"CommentReplyFrame\" class=\"wysiwyg\" name=\"editContent\" rows=\"20\" style=\"width:99%;\"></textarea>\r\n <div class=\"error error__content\"></div>\r\n <div style=\"text-align:center;\">\r\n <input type=\"button\" name=\"preview\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Preview\"/>\r\n <input type=\"button\" name=\"save\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Save\"/>\r\n </div>\r\n</div>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n\r\nvar firstPreview10700 = true;\r\nvar lastPreviewContent10700 = '';\r\n\r\nif (!window.moveCommentRevision) {\r\n moveCommentRevision = function(e, dir) {\r\n var p = e.parent();\r\n var revisionCount = parseInt(p.attr(\"revisionCount\"));\r\n var revision = parseInt(p.attr(\"revision\"));\r\n var next = revision + dir;\r\n var commentId = p.attr(\"commentId\");\r\n if (next >= 1 && next <= revisionCount) {\r\n $.post(\r\n \"/data/comment-data\",\r\n {action: \"revision\", commentId: commentId, revision: next},\r\n function(json) {\r\n if (json.success == \"true\") {\r\n var parentDiv = e;\r\n\r\n while (parentDiv !== null && (parentDiv[0].nodeName.toLowerCase() !== \"td\" || !parentDiv.hasClass(\"right\"))) {\r\n parentDiv = parentDiv.parent();\r\n }\r\n\r\n if (parentDiv === null) {\r\n return;\r\n }\r\n\r\n parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\").html(json.content);\r\n Codeforces.setupSpoilers(parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\"));\r\n p.attr(\"revision\", next);\r\n p.find(\"span.revision\").text(next);\r\n if (next == 1) {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"visible\");\r\n }\r\n if (next == revisionCount) {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"visible\");\r\n }\r\n\r\n window.updateTypography();\r\n MathJax.Hub.Typeset();\r\n } else {\r\n alert(e.error);\r\n }\r\n },\r\n \"json\"\r\n );\r\n }\r\n };\r\n}\r\n\r\n$(\"div[commentableId=10700] a.leftRevision\").click(function () {\r\n window.moveCommentRevision($(this), -1);\r\n return false;\r\n});\r\n\r\n$(\"div[commentableId=10700] a.rightRevision\").click(function () {\r\n window.moveCommentRevision($(this), +1);\r\n return false;\r\n});\r\n\r\n\r\n\r\n });\n </script>\n\r\n\r\n <script src=\"//codeforces.org/s/81027/js/swfobject-2.2.min.js\" type=\"text/javascript\"></script>\n <script src=\"//codeforces.org/s/81027/js/ftaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n if (window.evercookie) {\n var ec = new evercookie({\n history: false,\n silverlight: false,\n baseurl: '',\n asseturi: '/assets',\n phpuri: '/2fdcd78',\n pngPath: '/eps',\n etagPath: '/ees',\n cachePath: '/ecs'\n });\n\n var randomNumber = function () {\n return Math.random().toString(36).substr(2);\n };\n\n var randomToken = function () {\n return (randomNumber() + randomNumber()).substring(0, 18);\n };\n\n window._ftaa = \"\";\n\n ec.get(\"70a7c28f3de\", function (value) {\n window._ftaa = value;\n if (!window._ftaa) {\n window._ftaa = randomToken();\n ec.set(\"70a7c28f3de\", window._ftaa);\n }\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n } else {\n window._ftaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\n <script src=\"//codeforces.org/s/81027/js/bfaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n var fpCallback = function() {\n Fingerprint2.get({}, function(components) {\n window._bfaa = Fingerprint2.x64hash128(components.map(function (pair) { return pair.value }).join(), 31);\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n };\n if (typeof Fingerprint2 !== 'undefined') {\n if (window.requestIdleCallback) {\n requestIdleCallback(fpCallback)\n } else {\n setTimeout(fpCallback, 500)\n }\n } else {\n window._bfaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"a.new-root-comment\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n\r\n $(\".comment-table .reply a\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".vote-for-comment\").mouseover(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").mouseout(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").click(function () {\r\n var vote = $(this);\r\n var commentId = $(this).parent().attr(\"commentid\");\r\n var commentRating = $(this).parent().attr(\"data-commentRating\");\r\n var direction = $(this).attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n $.post(\"/data/comment/vote\", {commentId: commentId, _tta: Codeforces.tta(), vote: direction, commentRating: commentRating}, function(data) {\r\n if (direction != 0 && !ownComment && data[\"success\"] == \"true\") {\r\n vote.parent().find(\".vote-for-comment\").attr(\"voteDirection\", 0);\r\n if (direction == 1)\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n else {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.closest(\".CommentVoteFrame\").find(\".ComplaintFrame\").css(\"display\", \"inline-block\");\r\n }\r\n vote.find(\"img\").attr(\"popacity\", \"1.0\");\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n vote.parent().find(\".commentRating\").html(data[\"commentRating\"]);\r\n }\r\n Codeforces.showMessage(data[\"message\"]);\r\n }, \"json\");\r\n return false;\r\n });\r\n\r\n $(\".negative-comment-vote\").closest(\".comment-table\").addClass(\"comment-bad\");\r\n\r\n $(\".troll-comment-vote\").closest(\".comment\").css(\"display\", \"none\");\r\n\r\n $(\".too-negative-comment-vote\").closest(\".comment-table\").each(function () {\r\n var e = $(this);\r\n e.addClass(\"comment-too-bad\");\r\n var commentId = e.attr(\"commentId\");\r\n $(\"<div class='bad-comment-replacement ttypography'>The comment is hidden because of too negative feedback, click <a href=# class=show-bad-comment-link>here</a> to view it</div>\").appendTo(\r\n e.find(\".right\")\r\n );\r\n e.find(\".comment-content\").hide();\r\n e.find(\".show-bad-comment-link\").click(function () {\r\n e.find(\".comment-content\").show();\r\n e.find(\".bad-comment-replacement\").hide();\r\n return false;\r\n });\r\n });\r\n });\n </script>\n </div>\r\n\r\n <style type=\"text/css\">\r\n .new-comments-box {\r\n padding: 0.5em;\r\n width: 22px;\r\n font-size: 1.3rem;\r\n font-weight: bold !important;\r\n\r\n position: fixed;\r\n top: 40%;\r\n right: 0;\r\n opacity: 0.2;\r\n color: white;\r\n text-align: center;\r\n\r\n border: 1px solid #222;\r\n background-color: #888 !important;\r\n border-radius: 3px;\r\n -moz-border-radius: 3px;\r\n -webkit-border-radius: 3px;\r\n }\r\n\r\n .new-comments-box:hover {\r\n opacity: 1;\r\n }\r\n\r\n .new-comments-box .dir:hover {\r\n background: #3B5998 !important;\r\n cursor: pointer;\r\n }\r\n </style>\r\n\r\n <div class=\"new-comments-box\" data-position=\"outside\" data-index=\"-1\" style=\"display: none;\">\r\n <div class=\"up dir\" title=\"Ctrl+Up\">↑<hr/>\r\n </div>\r\n <div class=\"info\" title=\"New comments\"></div>\r\n <div class=\"down dir\" title=\"Ctrl+Down\">\r\n <hr/>↓\r\n </div>\r\n </div>\r\n\r\n <script>\r\n $(\".show-archived-checkbox\").change(function () {\r\n const checked = $(this).is(\":checked\");\r\n $.post(\"/data/comment-data\", {action: \"setShowArchived\", checked}, function (json) {\r\n if (json[\"success\"] !== \"true\") {\r\n alert(json[\"error\"]);\r\n } else {\r\n if (checked) {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are now displayed\")\r\n } else {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are no longer displayed\")\r\n }\r\n }\r\n });\r\n return false;\r\n });\r\n\r\n function gotoComment(direction) {\r\n var box = $(\".new-comments-box\");\r\n var index = parseInt(box.attr(\"data-index\"));\r\n if (index == -1)\r\n index = 0;\r\n else\r\n index = Math.max(0, Math.min(parseInt(box.find(\".info\").text()) - 1, index + direction));\r\n box.attr(\"data-index\", index);\r\n var comment = $($(\".comment .highlight-blue[commentId]\").get(index));\r\n $('html, body').animate({\r\n 'scrollTop': Math.max(0, comment.offset().top - ($(window).height() - comment.height()) / 2)\r\n });\r\n return false;\r\n }\r\n\r\n $(\".new-comments-box .down\").click(function () {\r\n return gotoComment(1);\r\n });\r\n\r\n $(\".new-comments-box .up\").click(function () {\r\n return gotoComment(-1);\r\n });\r\n\r\n $(document).keydown(function (e) {\r\n var code = (e.keyCode ? e.keyCode : e.which);\r\n if (e.ctrlKey) {\r\n if (code == 38 || code == 40) {\r\n gotoComment(code - 39);\r\n }\r\n }\r\n });\r\n\r\n var newCommentCount = $(\".comment .highlight-blue[commentId]\").length;\r\n if (newCommentCount > 0) {\r\n $(\".new-comments-box .info\").text(newCommentCount);\r\n $(\".new-comments-box\").show();\r\n }\r\n\r\n $('table.comment-table').mouseenter(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").addClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n\r\n $('table.comment-table').mouseleave(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").removeClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n </script>\r\n\r\n\r\n\r\n <script>\r\n function adjustTopicComplainFrames() {\r\n let topicIds = [];\r\n\r\n $(\".has-topic-id\").each(function () {\r\n const $this = $(this);\r\n const topicId = $this.attr(\"topicId\");\r\n if (topicId) {\r\n topicIds.push(topicId);\r\n }\r\n });\r\n\r\n $.post(\"/data/topics\", {\r\n action: \"findComplainableTopicIds\",\r\n topicIds: topicIds.join(\",\")\r\n }, function (json) {\r\n if (json[\"success\"] === \"true\") {\r\n for (const topicId of json[\"complainableTopicIds\"].split(\",\")) {\r\n $(\".has-topic-id[topicId=\" + topicId + \"]\").each(function () {\r\n $(this).find(\".meta .ComplaintFrame\").css(\"display\", \"inline-block\");\r\n });\r\n }\r\n }\r\n }, \"json\");\r\n }\r\n\r\n $(function () {\r\n adjustTopicComplainFrames();\r\n })\r\n </script>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-10684\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 10684, _tta: Codeforces.tta(), topicRevisionId: 36670, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-10684\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 10684, _tta: Codeforces.tta(), topicRevisionId: 36670, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n </div>\r\n </div>\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 22:13:07</span> (h1).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/81027/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/81027/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/81027/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/81027/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-81027.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'812875a2ab4016f4',t:'MTY5NjcwNTk4Ny4yMjQwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"}}},{"rowIdx":1964,"cells":{"problem_id":{"kind":"string","value":"389B"},"contest":{"kind":"string","value":"389"},"problem":{"kind":"string","value":"B"},"lang":{"kind":"string","value":"en"},"problem_title":{"kind":"string","value":"B. Fox and Cross"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">B. Fox and Cross</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Fox Ciel has a board with <span class=\"tex-span\"><i>n</i></span> rows and <span class=\"tex-span\"><i>n</i></span> columns. So, the board consists of <span class=\"tex-span\"><i>n</i> × <i>n</i></span> cells. Each cell contains either a symbol '<span class=\"tex-font-style-tt\">.</span>', or a symbol '<span class=\"tex-font-style-tt\">#</span>'.</p><p>A cross on the board is a connected set of exactly five cells of the board that looks like a cross. The picture below shows how it looks.</p><center><img class=\"tex-graphics\" src=\"https://espresso.codeforces.com/981c924d9ceccdb35249f2e19a70ba9aa2f53af0.png\" style=\"max-width: 100.0%;max-height: 100.0%;\"/></center><p>Ciel wants to draw several (may be zero) crosses on the board. Each cross must cover exactly five cells with symbols '<span class=\"tex-font-style-tt\">#</span>', and any cell with symbol '<span class=\"tex-font-style-tt\">#</span>' must belong to some cross. No two crosses can share a cell.</p><p>Please, tell Ciel if she can draw the crosses in the described way.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains an integer <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">3 ≤ <i>n</i> ≤ 100</span>) — the size of the board.</p><p>Each of the next <span class=\"tex-span\"><i>n</i></span> lines describes one row of the board. The <span class=\"tex-span\"><i>i</i></span>-th line describes the <span class=\"tex-span\"><i>i</i></span>-th row of the board and consists of <span class=\"tex-span\"><i>n</i></span> characters. Each character is either a symbol '<span class=\"tex-font-style-tt\">.</span>', or a symbol '<span class=\"tex-font-style-tt\">#</span>'.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Output a single line with \"<span class=\"tex-font-style-tt\">YES</span>\" if Ciel can draw the crosses in the described way. Otherwise output a single line with \"<span class=\"tex-font-style-tt\">NO</span>\".</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>5<br/>.#...<br/>####.<br/>.####<br/>...#.<br/>.....<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>YES<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>4<br/>####<br/>####<br/>####<br/>####<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>NO<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>6<br/>.#....<br/>####..<br/>.####.<br/>.#.##.<br/>######<br/>.#..#.<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>YES<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>6<br/>.#..#.<br/>######<br/>.####.<br/>.####.<br/>######<br/>.#..#.<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>NO<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3<br/>...<br/>...<br/>...<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>YES<br/></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>In example 1, you can draw two crosses. The picture below shows what they look like.</p><center><img class=\"tex-graphics\" src=\"https://espresso.codeforces.com/7d637ff5d63bd0a9a36dac1345dc34f19d178898.png\" style=\"max-width: 100.0%;max-height: 100.0%;\"/></center><p>In example 2, the board contains 16 cells with '<span class=\"tex-font-style-tt\">#</span>', but each cross contains 5. Since 16 is not a multiple of 5, so it's impossible to cover all.</p></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"bba809da43619bbcecc76ee190b5823a\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - B - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"f7b10a37dac6b25fba992a730cfa3b90bd8afecf\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - B - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/73366/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/73366/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/73366/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/73366/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/73366/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/73366/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/73366/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/73366/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/73366/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/73366/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/73366/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/73366/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/73366/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/73366/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/sidebar-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/a037fe51637846d9c7c725713cd840ea/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='bba809da43619bbcecc76ee190b5823a'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/73366/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/73366/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fcontest%2F389%2Fproblem%2FB%3Flocale%3Den\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"current\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='bba809da43619bbcecc76ee190b5823a'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:100%;\"><a style=\"color: black\" href=\"/contest/389\">Codeforces Round 228 (Div. 2)</a></th>\n </tr>\n <tr>\n <td class=\"left bottom\" colspan=\"1\"><span class=\"contest-state-phase\">Finished</span></td>\n </tr>\n </tbody>\n </table>\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Practice?\n <div class=\"top-links\">\n </div>\n </div>\n<div>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Want to solve the contest problems after the official contest ends? Just register for practice and you will be able to submit solutions.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"\" method=\"post\"><input type='hidden' name='csrf_token' value='bba809da43619bbcecc76ee190b5823a'/>\r\n <input type=\"hidden\" name=\"action\" value=\"registerForPractice\"/>\r\n <input type=\"submit\" name=\"submit\" value=\"Register for practice\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div> \r\n</div>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox ContestVirtualFrame borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Virtual participation <i class=\"sidebar-caption-icon las la-angle-down\"></i>\r\n\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\" \"\r\n\r\n data-page-url=\"/data/sidebarFrames\"\r\n\r\n>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests.\n\nIf you've seen these problems, a virtual contest is not for you - solve these problems in the archive.\n\nIf you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.\n\nNever use someone else's code, read the tutorials or communicate with other person during a virtual contest.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"/contest/389/virtual\" method=\"get\">\r\n <input type=\"submit\" name=\"submit\" value=\"Start virtual contest\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div>\r\n</div>\r\n <script>\r\n $(function () {\r\n $(\".ContestVirtualFrame .sidebar-caption-icon\").click(function() {\r\n $(this).toggleClass(\"la-angle-down la-angle-right\");\r\n const $target = $(this).parent().next();\r\n $target.toggle();\r\n const dataPageUrl = $target.attr(\"data-page-url\");\r\n const collapsed = $(this).hasClass(\"la-angle-right\");\r\n const params = {\r\n action: \"setCollapsed\",\r\n sidebarFrameSimpleClassName: \"ContestVirtualFrame\",\r\n collapsed\r\n };\r\n $.each($target[0].attributes, function(i, a) {\r\n const name = a.name;\r\n if (name.startsWith(\"data-extra-key-\")) {\r\n const key = a.value;\r\n const keyIndex = parseInt(name.substring(\"data-extra-key-\".length));\r\n const value = $target.attr(\"data-extra-value-\" + keyIndex);\r\n params[key] = value;\r\n }\r\n });\r\n $.post(dataPageUrl, params, function (result) {\r\n if (result[\"success\"] !== \"true\") {\r\n Codeforces.showMessage(\"Failed to save collapsed state.\");\r\n }\r\n }, \"json\");\r\n return false;\r\n });\r\n })\r\n </script>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Problem tags\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Greedy algorithms\">\r\n greedy\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Implementation problems, programming technics, simulation\">\r\n implementation\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Difficulty\">\r\n *1100\r\n</span>\r\n </div>\n <div style=\"clear:both;text-align:right;font-size:1.1rem;\">\r\n <span title=\"Please login into the Codeforces\" class=\"notice\">No tag edit access</span>\r\n </div>\r\n</div>\r\n </div>\n\r\n<form id=\"addTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='bba809da43619bbcecc76ee190b5823a'/>\r\n <input name=\"action\" type=\"hidden\" value=\"addTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"6401\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<form id=\"removeTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='bba809da43619bbcecc76ee190b5823a'/>\r\n <input name=\"action\" type=\"hidden\" value=\"removeTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"6401\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<script type=\"text/javascript\">\r\n $(\".tag-box img\").click(function () {\r\n var tagName = $(this).attr(\"value\");\r\n Codeforces.confirm(\"Are you sure you want to remove this tag?\", function () {\r\n $(\"#removeTagForm input[name=tagName]\").val(tagName);\r\n $(\"#removeTagForm\").submit();\r\n }, function () {\r\n }, \"Yes\", \"No\");\r\n });\r\n\r\n $(\"#addTagLink\").click(function () {\r\n $(this).hide();\r\n $(\"#addTagLabel\").show();\r\n return false;\r\n });\r\n\r\n $(\"#addTagSelect\").change(function () {\r\n var tagName = $(this).val();\r\n if (tagName === \"\") {\r\n $(\"#addTagLabel\").hide();\r\n $(\"#addTagLink\").show();\r\n } else {\r\n $(\"#addTagForm input[name=tagName]\").val(tagName);\r\n $(\"#addTagForm\").submit();\r\n }\r\n });\r\n</script>\r\n\r\n<style type=\"text/css\">\r\n#new-resource-form tr td {\r\npadding-top: 0.5em;\r\n}\r\n#new-resource-form input:not([type=\"submit\"]) {\r\nfont-size: 0.8em;\r\n}\r\n#new-resource-form select {\r\nfont-size: 0.8em;\r\n}\r\n.new-resource-error {\r\nfont-size: 0.8em;\r\n}\r\n.resource-locale {\r\ncolor: #666;\r\nfont-family: Consolas, \"Andale Mono WT\", \"Andale Mono\", \"Lucida Console\", \"Lucida Sans Typewriter\", \"DejaVu Sans Mono\", \"Bitstream Vera Sans Mono\", \"Liberation Mono\", \"Nimbus Mono L\", Monaco, \"Courier New\", Courier, monospace;\r\n}\r\n</style>\r\n<div class=\"roundbox sidebox sidebar-menu borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Contest materials\n<div class=\"top-links\">\n</div>\n</div>\n<ul>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/10605\" title=\"Codeforces Round #228\" target=\"_blank\">Codeforces Round #228</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"2189:2190\" resourceName=\"Announcement\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/10629\" title=\"Codeforces Round #228 — Editorial\" target=\"_blank\">Tutorial <span class=\"resource-locale\">(en)</span></a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"2191\" resourceName=\"Codeforces Round #228 — Editorial\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n</ul>\r\n</div></div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li class=\"current selectedLava\"><a\r\n href=\"/contest/389\">Problems</a></li>\r\n <li><a\r\n href=\"/contest/389/submit\">Submit Code</a></li>\r\n <li><a\r\n href=\"/contest/389/my\">My Submissions</a></li>\r\n <li><a\r\n href=\"/contest/389/status\">Status</a></li>\r\n <li><a\r\n href=\"/contest/389/hacks\">Hacks</a></li>\r\n <li><a\r\n href=\"/contest/389/room/1\">Room</a></li>\r\n <li><a\r\n href=\"/contest/389/standings\">Standings</a></li>\r\n <li><a\r\n href=\"/contest/389/customtest\">Custom Invocation</a></li>\r\n</ul>\r\n</div>\n\r\n <style>\r\n #facebox .content:has(.diff-popup) {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n }\r\n\r\n .testCaseMarker {\r\n position: absolute;\r\n font-weight: bold;\r\n font-size: 1rem;\r\n }\r\n\r\n .diff-popup {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n display: none;\r\n overflow: auto;\r\n }\r\n\r\n .input-output-copier {\r\n font-size: 1.2rem;\r\n float: right;\r\n color: #888 !important;\r\n cursor: pointer;\r\n border: 1px solid rgb(185, 185, 185);\r\n padding: 3px;\r\n margin: 1px;\r\n line-height: 1.1rem;\r\n text-transform: none;\r\n }\r\n\r\n .input-output-copier:hover {\r\n background-color: #def;\r\n }\r\n\r\n .test-explanation textarea {\r\n width: 100%;\r\n height: 1.5em;\r\n }\r\n\r\n .pending-submission-message {\r\n color: darkorange !important;\r\n }\r\n </style>\r\n <script>\r\n const OPENING_SPACE = String.fromCharCode(1001);\r\n const CLOSING_SPACE = String.fromCharCode(1002);\r\n\r\n const nodeToText = function (node, pre) {\r\n let result = [];\r\n\r\n if (node.tagName === \"SCRIPT\" || node.tagName === \"math\"\r\n || (node.classList && node.classList.contains(\"input-output-copier\")))\r\n return [];\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(OPENING_SPACE);\r\n }\r\n\r\n if (node.nodeType === Node.TEXT_NODE) {\r\n let s = node.textContent;\r\n if (!pre) {\r\n s = s.replace(/\\s+/g, \" \");\r\n }\r\n if (s.length > 0) {\r\n result.push(s);\r\n }\r\n }\r\n\r\n if (pre && node.tagName === \"BR\") {\r\n result.push(\"\\n\");\r\n }\r\n\r\n node.childNodes.forEach(function (child) {\r\n result.push(nodeToText(child, node.tagName === \"PRE\").join(\"\"));\r\n });\r\n\r\n if (node.tagName === \"DIV\"\r\n || node.tagName === \"P\"\r\n || node.tagName === \"PRE\"\r\n || node.tagName === \"UL\"\r\n || node.tagName === \"LI\"\r\n ) {\r\n result.push(\"\\n\");\r\n }\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(CLOSING_SPACE);\r\n }\r\n\r\n return result;\r\n }\r\n\r\n const isSpecial = function (c) {\r\n return c === ',' || c === '.' || c === ';' || c === ')' || c === ' ';\r\n }\r\n\r\n const convertStatementToText = function(statmentNode) {\r\n const text = nodeToText(statmentNode, false).join(\"\").replace(/ +/g, \" \").replace(/\\n\\n+/g, \"\\n\\n\");\r\n let result = [];\r\n for (let i = 0; i < text.length; i++) {\r\n const c = text.charAt(i);\r\n if (c === OPENING_SPACE) {\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"B\" data-uuid=\"ps_fad68e93f31ac1ce02ac7d043d01a35a880762a0\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">B. Fox and Cross</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Fox Ciel has a board with <span class=\"tex-span\"><i>n</i></span> rows and <span class=\"tex-span\"><i>n</i></span> columns. So, the board consists of <span class=\"tex-span\"><i>n</i> × <i>n</i></span> cells. Each cell contains either a symbol '<span class=\"tex-font-style-tt\">.</span>', or a symbol '<span class=\"tex-font-style-tt\">#</span>'.</p><p>A cross on the board is a connected set of exactly five cells of the board that looks like a cross. The picture below shows how it looks.</p><center><img class=\"tex-graphics\" src=\"https://espresso.codeforces.com/981c924d9ceccdb35249f2e19a70ba9aa2f53af0.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></center><p>Ciel wants to draw several (may be zero) crosses on the board. Each cross must cover exactly five cells with symbols '<span class=\"tex-font-style-tt\">#</span>', and any cell with symbol '<span class=\"tex-font-style-tt\">#</span>' must belong to some cross. No two crosses can share a cell.</p><p>Please, tell Ciel if she can draw the crosses in the described way.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains an integer <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">3 ≤ <i>n</i> ≤ 100</span>) — the size of the board.</p><p>Each of the next <span class=\"tex-span\"><i>n</i></span> lines describes one row of the board. The <span class=\"tex-span\"><i>i</i></span>-th line describes the <span class=\"tex-span\"><i>i</i></span>-th row of the board and consists of <span class=\"tex-span\"><i>n</i></span> characters. Each character is either a symbol '<span class=\"tex-font-style-tt\">.</span>', or a symbol '<span class=\"tex-font-style-tt\">#</span>'.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Output a single line with "<span class=\"tex-font-style-tt\">YES</span>" if Ciel can draw the crosses in the described way. Otherwise output a single line with "<span class=\"tex-font-style-tt\">NO</span>".</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>5<br />.#...<br />####.<br />.####<br />...#.<br />.....<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>YES<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>4<br />####<br />####<br />####<br />####<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>NO<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>6<br />.#....<br />####..<br />.####.<br />.#.##.<br />######<br />.#..#.<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>YES<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>6<br />.#..#.<br />######<br />.####.<br />.####.<br />######<br />.#..#.<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>NO<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3<br />...<br />...<br />...<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>YES<br /></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>In example 1, you can draw two crosses. The picture below shows what they look like.</p><center><img class=\"tex-graphics\" src=\"https://espresso.codeforces.com/7d637ff5d63bd0a9a36dac1345dc34f19d178898.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></center><p>In example 2, the board contains 16 cells with '<span class=\"tex-font-style-tt\">#</span>', but each cross contains 5. Since 16 is not a multiple of 5, so it's impossible to cover all.</p></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=B]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== statementText) {\r\n $problem.find(\".diff-notifier\").show();\r\n\r\n $problem.find(\".diff-notifier-close\").click(function() {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n $problem.find(\".diff-notifier\").hide();\r\n });\r\n\r\n $problem.find(\"a.view-changes\").click(function() {\r\n $.post(\"/data/diff\", {action: \"getDiff\", a: previousStatementText, b: statementText}, function (result) {\r\n if (result[\"success\"] === \"true\") {\r\n Codeforces.facebox(\".diff-popup\", \"//codeforces.org/s/73366\");\r\n $(\"#facebox .diff-popup\").html(result[\"diff\"]);\r\n }\r\n }, \"json\");\r\n });\r\n }\r\n } else {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n }\r\n });\r\n });\r\n </script>\r\n\r\n\r\n<script type=\"text/javascript\">\r\n $(document).ready(function () {\r\n window.changedTests = new Set();\r\n\r\n function endsWith(string, suffix) {\r\n return string.indexOf(suffix, string.length - suffix.length) !== -1;\r\n }\r\n\r\n const inputFileDiv = $(\"div.input-file\");\r\n const inputFile = inputFileDiv.text();\r\n const outputFileDiv = $(\"div.output-file\");\r\n const outputFile = outputFileDiv.text();\r\n\r\n\r\n if (!endsWith(inputFile, \"standard input\")\r\n && !endsWith(inputFile, \"standard input\")) {\r\n inputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n if (!endsWith(outputFile, \"standard output\")\r\n && !endsWith(outputFile, \"standard output\")) {\r\n outputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n const titleDiv = $(\"div.header div.title\");\r\n\r\n\r\n\r\n String.prototype.replaceAll = function (search, replace) {\r\n return this.split(search).join(replace);\r\n };\r\n\r\n $(\".sample-test .title\").each(function () {\r\n const preId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n const cpyId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n\r\n $(this).parent().find(\"pre\").attr(\"id\", preId);\r\n const $copy = $(\"<div title='Copy' data-clipboard-target='#\" + preId + \"' id='\" + cpyId + \"' class='input-output-copier'>Copy</div>\");\r\n $(this).append($copy);\r\n\r\n const clipboard = new Clipboard('#' + cpyId, {\r\n text: function (trigger) {\r\n const pre = document.querySelector('#' + preId);\r\n const lines = pre.querySelectorAll(\".test-example-line\");\r\n return Codeforces.filterClipboardText(pre.innerText, lines.length);\r\n }\r\n });\r\n\r\n const isInput = $(this).parent().hasClass(\"input\");\r\n\r\n clipboard.on('success', function (e) {\r\n if (isInput) {\r\n Codeforces.showMessage(\"The example input has been copied into the clipboard\");\r\n } else {\r\n Codeforces.showMessage(\"The example output has been copied into the clipboard\");\r\n }\r\n e.clearSelection();\r\n });\r\n });\r\n\r\n $(\".test-form-item input\").change(function () {\r\n addPendingSubmissionMessage($($(this).closest(\"form\")), \"You changed the answer, do not forget to submit it if you want to save the changes\");\r\n const index = $(this).closest(\".problemindexholder\").attr(\"problemindex\");\r\n let test = \"\";\r\n $(this).closest(\"form input\").each(function () {\r\n const test_ = $(this).attr(\"name\");\r\n if (test_ && test_.substring(0, 4) === \"test\") {\r\n test = test_;\r\n }\r\n });\r\n if (index.length > 0 && test.length > 0) {\r\n const indexTest = index + \"::\" + test;\r\n window.changedTests.add(indexTest);\r\n }\r\n });\r\n\r\n $(window).on('beforeunload', function () {\r\n if (window.changedTests.size > 0) {\r\n return 'Dialog text here';\r\n }\r\n });\r\n\r\n autosize($('.test-explanation textarea'));\r\n\r\n $(\".test-example-line\").hover(function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n let top = 1E20;\r\n let left = 1E20;\r\n let problem = $(this).closest(\".problemindexholder\");\r\n $(this).closest(\".input\").find(\".\" + clazz).css(\"background-color\", \"#FFFDE7\").each(function() {\r\n top = Math.min(top, $(this).offset().top);\r\n left = Math.min(left, $(this).offset().left);\r\n });\r\n let testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n if (testCaseMarker.length === 0) {\r\n const html = \"<div class=\\\"testCaseMarker testCaseMarker_\" + end + \" notice\\\"></div>\";\r\n problem.append($(html));\r\n testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n }\r\n if (testCaseMarker) {\r\n testCaseMarker.show()\r\n .offset({top, left: left - 20})\r\n .text(end);\r\n }\r\n }\r\n }\r\n });\r\n }, function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n $(\".\" + clazz).css(\"background-color\", \"\");\r\n $(this).closest(\".problemindexholder\").find(\".testCaseMarker_\" + end).hide();\r\n }\r\n }\r\n });\r\n });\r\n\r\n });\r\n</script>\r\n\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 05:38:37</span> (j3).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/73366/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/73366/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/73366/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/73366/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-73366.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'8122c4dd3eb50069',t:'MTY5NjY0NjMxNy43MjkwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"},"long_tags":{"kind":"string","value":"[\"Greedy algorithms\", \"Implementation problems, programming technics, simulation\"]"},"short_tags":{"kind":"string","value":"[\"greedy\", \"implementation\", \"*1100\"]"},"tutorial_link":{"kind":"string","value":"https://codeforces.com/blog/entry/10629"},"tutorial_page":{"kind":"string","value":"\r\n\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"74361418aed3add319d25ce966ceafdf\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"h1\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Codeforces Round #228 — Editorial - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n \n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Codeforces Round #228 — Editorial - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/81027/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/81027/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/81027/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/81027/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/81027/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/81027/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/81027/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/81027/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/81027/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/81027/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/81027/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/81027/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/81027/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/81027/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/573cedc6b04c15481941f418269f4057/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='74361418aed3add319d25ce966ceafdf'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/81027/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fblog%2Fentry%2F10629\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='74361418aed3add319d25ce966ceafdf'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Pay attention\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n <div style=\"text-align:center;border-bottom: 1px solid rgb(185, 185, 185);margin:0 -0.5em 0.5em -0.5em;padding: 0 1em 0.5em 1em;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 1, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:51:54</span><br/><a href=\"/contestRegistration/1876\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n <div style=\"text-align:center;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 2, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:51:54</span><br/><a href=\"/contestRegistration/1877\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='74361418aed3add319d25ce966ceafdf'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n </label>\r\n </div>\r\n <div style=\"padding: 0 1em 1em 1em;text-align:right;\">\r\n <input style=\"height:1.65em;padding:0 0.75em;\" type=\"submit\" value=\"Find\"/>\r\n </div>\r\n </form>\r\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".handleBox\").autocomplete(\"/data/handles\", {\r\n delay: 200,\r\n width: 200,\r\n selectFirst: false,\r\n matchContains: true,\r\n minChars: 3\r\n });\r\n $(\".handleForm\").attr(\"autocomplete\", \"off\").submit(function () {\r\n var link = \"/profile/userHandle\".replace(\r\n \"userHandle\", $(this).find(\".handleBox\").val()\r\n );\r\n window.location = link;\r\n return false;\r\n });\r\n });\n </script>\n\r\n\r\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Recent actions\n <div class=\"top-links\">\n </div>\n </div>\n <div class=\"recent-actions\">\r\n <ul>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/121073\">Meta Hacker Cup 2023 Round 1</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/.Danet\" title=\"Expert .Danet\" class=\"rated-user user-blue\">.Danet</a> →\r\n <a href=\"/blog/entry/121172\">[TLE on pretest1]</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\" class=\"rated-user user-red\">Pyqe</a> →\r\n <a href=\"/blog/entry/121025\">Codeforces Round #902 (Div. 1, Div. 2, based on COMPFEST 15 — Final Round)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pranshu_Pandya\" title=\"Specialist Pranshu_Pandya\" class=\"rated-user user-cyan\">Pranshu_Pandya</a> →\r\n <a href=\"/blog/entry/121171\">An Interesting Tree Problem</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/sszcdjr\" title=\"Master sszcdjr\" class=\"rated-user user-orange\">sszcdjr</a> →\r\n <a href=\"/blog/entry/119859\">Codeforces Round 896 (Div. 1, Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/119880\">It's Happening! Meta Hacker Cup 2023 Schedule</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/DaviddeGea1\" title=\"Expert DaviddeGea1\" class=\"rated-user user-blue\">DaviddeGea1</a> →\r\n <a href=\"/blog/entry/70917\">Number of ways of dividing an array into 2 parts such that sum of each part is > k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bekh\" title=\"Master Bekh\" class=\"rated-user user-orange\">Bekh</a> →\r\n <a href=\"/blog/entry/74245\">Questions and doubts regarding Aliens DP trick</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a> →\r\n <a href=\"/blog/entry/8192\">Codeforces Round #190 — Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/hocky\" title=\"Candidate Master hocky\" class=\"rated-user user-violet\">hocky</a> →\r\n <a href=\"/blog/entry/95323\">FBHC wuining uw Day? Incwease uw stacc size! (ㅅ´ ˘ `)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/liouzhou_101\" title=\"International Master liouzhou_101\" class=\"rated-user user-orange\">liouzhou_101</a> →\r\n <a href=\"/blog/entry/87598\">Editorial of Codeforces Round #700</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/yeon_gist\" title=\"Newbie yeon_gist\" class=\"rated-user user-gray\">yeon_gist</a> →\r\n <a href=\"/blog/entry/121170\">plusMinusPermutation computing error</a>\r\n <img alt=\"Text created or updated\" title=\"Text created or updated\" src=\"//codeforces.org/s/81027/images/icons/x-update-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/altforminuscontribution\" title=\"Newbie altforminuscontribution\" class=\"rated-user user-gray\">altforminuscontribution</a> →\r\n <a href=\"/blog/entry/121162\">My screen get unexpectedly big, what should I do</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/atcoder_official\" title=\"Unrated, atcoder_official\" class=\"rated-user user-black\">atcoder_official</a> →\r\n <a href=\"/blog/entry/121120\">We will hold UNIQUE VISION Programming Contest 2023 Autumn(AtCoder Beginner Contest 323)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/YouStill_DontKnowMeYet\" title=\"Candidate Master YouStill_DontKnowMeYet\" class=\"rated-user user-violet\">YouStill_DontKnowMeYet</a> →\r\n <a href=\"/blog/entry/117659\">[GYM] Al-Baath Collegiate Programming Contest 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/ankancool\" title=\"Expert ankancool\" class=\"rated-user user-blue\">ankancool</a> →\r\n <a href=\"/blog/entry/121136\">Invitation to AstroByte 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/GeZhiyuan\" title=\"Grandmaster GeZhiyuan\" class=\"rated-user user-red\">GeZhiyuan</a> →\r\n <a href=\"/blog/entry/120943\">Codeforces Round 901 (Div. 1, Div. 2) Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a> →\r\n <a href=\"/blog/entry/120772\">PSA: Increase your stack size before the Meta Hacker Cup, here's how</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/dino_merlin\" title=\"Expert dino_merlin\" class=\"rated-user user-blue\">dino_merlin</a> →\r\n <a href=\"/blog/entry/121145\">Intuitive approach for CEOI Kangaroo?</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/icecuber\" title=\"Grandmaster icecuber\" class=\"rated-user user-red\">icecuber</a> →\r\n <a href=\"/blog/entry/70018\">CSES DP section editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bn00b\" title=\"Newbie Bn00b\" class=\"rated-user user-gray\">Bn00b</a> →\r\n <a href=\"/blog/entry/98820\">[FEATURE REQUEST : ATCODER] TOPICS TAGS AND SORTING BY SOLVE COUNT</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a> →\r\n <a href=\"/blog/entry/121163\">AtCoder Regular Contest 166 Announcement</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/windva\" title=\"Grandmaster windva\" class=\"rated-user user-red\">windva</a> →\r\n <a href=\"/blog/entry/120644\">Codeforces Round 899 (Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Misa-Misa\" title=\"Expert Misa-Misa\" class=\"rated-user user-blue\">Misa-Misa</a> →\r\n <a href=\"/blog/entry/121157\">Someone please help me understand this.</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/shivam565\" title=\"Specialist shivam565\" class=\"rated-user user-cyan\">shivam565</a> →\r\n <a href=\"/blog/entry/108348\">Total number of subarrays with sum atmost k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n </ul>\r\n </div>\r\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/recent-actions\">Detailed →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n</div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li><a\r\n href=\"/profile/cgy4ever\">cgy4ever</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/cgy4ever\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/cgy4ever\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/cgy4ever\">Submissions</a></li>\r\n <li><a\r\n href=\"/groups/with/cgy4ever\">Groups</a></li>\r\n <li><a\r\n href=\"/contests/with/cgy4ever\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/cgy4ever\">Problemsetting</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/cgy4ever\" style=\"text-decoration:none;color:black !important;\">cgy4ever's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"10684\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/10629\"> <p>Codeforces Round #228 — Editorial</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a>,\r\n <span class=\"format-humantime\" title=\"Feb/03/2014 22:14\">10 years ago</span>,\r\n \r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p>You can find the editorial and my solutions here: <a href=\"https://github.com/cgy4ever/CF228\">https://github.com/cgy4ever/CF228</a></p><p><a href=\"/contest/389/problem/A\" title=\"Codeforces Round 228 (Div. 2)\">389A - Fox and Number Game</a></p><p>First we know that: in the optimal solution, all number will be equal: otherwise we can pick a and b (a < b) then do b = b — a, it will make the answer better.</p><p>Then we need an observation: after each operation, the GCD (Greatest common divisor) of all number will remain same. It can be proved by this lemma: if g is a divisor of all number of x[], then after the operation, g is still the divisor of these numbers, and vice versa.</p><p>So in the end, all number will become the GCD of x[].</p><p>Another solution that can pass is: While there exist x[i] > x[j], then do x[i] -= x[j]. We can select arbitrary i and j if there exist more than 1 choice.</p><p><a href=\"/contest/389/problem/B\" title=\"Codeforces Round 228 (Div. 2)\">389B - Fox and Cross</a></p><p>Let's define the first # of a shape is the cell contain # that have the lexicographical smallest coordinate. Then the first # of a cross is the top one.</p><p>Then let x be the first # of the given board. (If the board is empty, then we can draw it with zero crosses.) x must be covered by a cross, and x must be the first # of the cross. (You can try 4 other positions, it will cause a lexicographical smaller # in the board than x)</p><p>So we try to cover this x use one cross, if it leads some part of the cross covers a '.', then there will be no solution. If not, we just reduce the number of # in the board by 4, we can do this again and again.</p><p><a href=\"/contest/389/problem/C\" title=\"Codeforces Round 228 (Div. 2)\">389C - Fox and Box Accumulation</a> / <a href=\"/contest/388/problem/A\" title=\"Codeforces Round 228 (Div. 1)\">388A - Fox and Box Accumulation</a></p><p>We need some observation:</p> <ol> <li><p>There exists an optimal solution such that: in any pile, the box on the higher position will have a smaller strength.</p></li> <li><p>Let k be the minimal number of piles, then there exists an optimal solution such that: The height of all piles is n/k or n/k+1 (if n%k=0, then all of them have the height n/k).</p></li> </ol><p>We can prove them by exchange argument: from an optimal solution, swap the boxes in it to make above property holds, and we can ensure it will remain valid while swapping.</p><p>Then for a given k, we can check whether there exist a solution: the i-th (indexed from 0) smallest strength needs to be at least i/k.</p><p>So we can do binary search (or just enumerate, since n is only 100) on k.</p><p><a href=\"/contest/389/problem/D\" title=\"Codeforces Round 228 (Div. 2)\">389D - Fox and Minimal path</a> / <a href=\"/contest/388/problem/B\" title=\"Codeforces Round 228 (Div. 1)\">388B - Fox and Minimal path</a></p><p>First we need to know how to calculate the number of different shortest paths from vertex 1 to vertex 2: it can be done by dp: dp[1] = 1, dp[v] = sum{dp[t] | dist(1,t) = dist(1,v) — 1}, then dp[2] is our answer.</p><p>We need to do dp layer by layer. (first we consider vertexes have distance 1 to node 1, then vertexes have distance 2 to node 1 and so on.) So we can construct the graph layer by layer, and link edges to control the dp value of it.</p><p>My solution is construct the answer by binary express: If k is 19, then we need some vertexes in previous layer such that the dp value is 16, 2 and 1. So we just need a way to construct layer with dp value equals to 2^k.</p><p>In the first layer, it contains one node: 1, it has the dp value 1. In the next layer, we can construct 2 nodes, with dp value equals to 1. (We use [1 1] to denote it). And the next layer is [1 1 2], then [1 1 2 4], [1 1 2 4 8] and so on. So we need about 30 layers such that gets all 2^k where k < 30. It uses about 500 nodes.</p><p><a href=\"/contest/389/problem/E\" title=\"Codeforces Round 228 (Div. 2)\">389E - Fox and Card Game</a> / <a href=\"/contest/388/problem/C\" title=\"Codeforces Round 228 (Div. 1)\">388C - Fox and Card Game</a></p><p>First let's consider the case which all piles have even size. In this case, we can prove: in the optimal play, Ciel will gets all top most half cards of each pile, and Jiro gets the remain cards.</p><p>We can prove by these facts: Ciel have a strategy to ensure she can get this outcome and Jiro also have a strategy to ensure this outcome. (For Jiro this strategy is easy: just pick the card from pile that Ciel have just picked. For Ciel it's a little bit harder.)</p><p>Why we can conclude they are both the optimal strategy? Ciel just can't win more, because if she played with Jiro with above strategy, Jiro will get the bottom half of each pile.</p><p>Then we come back with cases that contain odd size piles. The result is: for odd size pile, Ciel will get the top (s-1)/2 cards and Jiro will get the bottom (s-1)/2 cards. Then what about the middle one? Let's denote S is all such middle cards. Then we define a reduced game: In each turn, they pick one card from S. The optimal play for this game is easy: Ciel gets the max one, and Jiro gets the 2nd largest one, and Ciel gets the 3rd largest one and so on.</p><p>We can prove Ciel have a strategy to get: all top half parts + cards she will get in the optimal play in the reduced game. And Jiro also have a strategy to get: all bottom half parts + cards he will get in the optimal play in the reduced game. And these strategy are optimal.</p><p><a href=\"/contest/388/problem/D\" title=\"Codeforces Round 228 (Div. 1)\">388D - Fox and Perfect Sets</a></p><p>A perfect set correspond to a linear space, so we can use base to represent it. We do the Gauss–Jordan elimination of vectors in that set, and can get an unique base. (Note that we need to to the all process of Gauss–Jordan elimination, including the elimination after it reached upper triangular)</p><p>And we can construct the bases bit by bit from higher bit to lower, for a bit:</p> <ol> <li><p>We can add a vector to the base such that the bit is the highest bit of that vector. And at this time, all other vector will have 0 in this bit.</p></li> <li><p>Otherwise we need to assign this bit of each vector already in the base. If now we have k vector, then we have 2^k choices.</p></li> </ol><p>And when we do this, we need to know what's the maximal vector in this space. It's not hard:</p> <ol> <li><p>If we add a vector, then in the maximal vector, this bit will be 1.</p></li> <li><p>Otherwise, if we don't have any vector in base yet, then this bit will be 0. Otherwise there will be 2^(k-1) choices results in this bit of maximal vector will be 0, and 2^(k-1) choices results in 1.</p></li> </ol><p>So we can solve this task by DP bit by bit.</p><p><a href=\"/contest/388/problem/E\" title=\"Codeforces Round 228 (Div. 1)\">388E - Fox and Meteor Shower</a></p><p>All tasks beside this are very easy to code. And this one focus on implementation.</p><p>We can represent the orbit of each meteor by a line in 3D space. (we use an axis to represent the time, and two axis to represent the position on the plane.)</p><p>Then the problem becomes: we have some lines in 3D space (they are not complete coincide), find a largest clique such that each pair of lines touch at some point.</p><p>We need this observation: If there are 3 lines in the optimal clique, and these 3 lines are not share a common point, then all line in this clique will on a plane.</p><p>By using this observation, we only need to consider 2 cases:</p> <ol> <li><p>All lines in the clique have a common point.</p></li> <li><p>All lines in the clique are on the same plane.</p></li> </ol><p>Both are easy tasks in theory, but it needs some coding.</p><p>There are two ways:</p> <ol> <li><p>Use integer anywhere. Note that the coordinates of intersection can be rational number, but can't be irrational, so we could do this. We can use some way to encode the plane, direction.</p></li> <li><p>Use floating number. To count same number of points, we can sort (x, y, z) by using the following compare function: if (abs(A.x — B.x) > eps){return A.x < B.x} otherwise { if(abs(A.y-B.y)>eps){return A.y < B.y} otherwise return A.z < B.z}.</p></li> </ol></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/388\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 228 (Div. 1)</a> </span>\r\n </div>\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/389\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 228 (Div. 2)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-21-10684\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"21\",\n blogEntryId: \"10629\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-10684\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+45</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-10684\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/cgy4ever\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/cgy4ever\">\n cgy4ever\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Feb/03/2014 22:14\">10 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/10629#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/10629#comments\">\n 44\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"10700\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (39)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159842\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/YaleZ\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/24526/avatar/5b17db1affad55a5.jpg'/> </a>\n <div><a href=\"/profile/YaleZ\" title=\"Expert YaleZ\" class=\"rated-user user-blue\">YaleZ</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2014 22:38\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159842\" href=\"?#comment-159842\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"159842\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"159842\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"24526\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159842\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thank for timely editorial. I think Markdown is better when publish something on Github. Isn't it?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159842 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159842 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159842\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159846\" commentParentId=\"159842\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/cgy4ever\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2014 22:43\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159846\" href=\"?#comment-159846\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159842\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159846\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"11\"\r\n data-commentUserId=\"62\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+11</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159846\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Yes, I'm working on it. :)</p><p>The website seems to be not stable at this time. So I post them in other sites to ensure all people can see it.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159846 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159846 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159846\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159857\" commentParentId=\"159846\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Nodir.Daminov\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/71439/avatar/d6d2016f6dfe5ecd.jpg'/> </a>\n <div><a href=\"/profile/Nodir.Daminov\" title=\"Candidate Master Nodir.Daminov\" class=\"rated-user user-violet\">Nodir.Daminov</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2014 22:58\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159857\" href=\"?#comment-159857\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159846\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159857\" class=\"CommentVoteFrame\"\r\n class=\"too-negative-comment-vote\"\r\n data-commentRating=\"-35\"\r\n data-commentUserId=\"71439\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-35</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159857\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Maaan is it so hard to COPY ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159857 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159857 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159857\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159874\" commentParentId=\"159857\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/cgy4ever\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2014 23:19\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159874\" href=\"?#comment-159874\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159857\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159874\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"12\"\r\n data-commentUserId=\"62\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+12</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159874\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Sorry for the delay.</p><p>When I was submitting my post that contains the editorial, it always returns "Codeforces is now unavailable." so I just can't post it.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159874 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159874 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159874\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159859\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/BishalG\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/60637/avatar/d21ddf49bbd1630c.jpg'/> </a>\n <div><a href=\"/profile/BishalG\" title=\"Expert BishalG\" class=\"rated-user user-blue\">BishalG</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2014 22:58\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159859\" href=\"?#comment-159859\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159859\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"60637\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159859\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Nice problemSets @<a class=\"rated-user user-orange\" href=\"/profile/cgy4ever\" title=\"International Master cgy4ever\">cgy4ever</a> , although I misunderstood the problem-B <a href=\"/contest/389/problem/B\" title=\"Codeforces Round 228 (Div. 2)\">389B - Fox and Cross</a> upto 1 hrs :( </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159859 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159859 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159859\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159867\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Mr.ink\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Mr.ink\" title=\"Expert Mr.ink\" class=\"rated-user user-blue\">Mr.ink</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2014 23:07\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159867\" href=\"?#comment-159867\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159867\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"128876\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159867\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>due to my slow internet speed i can not see your editorial on github because my country internet has problem with https! </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159867 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159867 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159867\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159881\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Mr.ink\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Mr.ink\" title=\"Expert Mr.ink\" class=\"rated-user user-blue\">Mr.ink</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2014 23:38\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159881\" href=\"?#comment-159881\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159881\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"128876\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159881\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>does anyone have a better solution for div2 C problem?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159881 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159881 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159881\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159883\" commentParentId=\"159881\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/t_thirupathi\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/146179/avatar/98c28348196ce4ca.jpg'/> </a>\n <div><a href=\"/profile/t_thirupathi\" title=\"Specialist t_thirupathi\" class=\"rated-user user-cyan\">t_thirupathi</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2014 23:42\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159883\" href=\"?#comment-159883\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159881\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159883\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"146179\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159883\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Have a look at mine <a href=\"/contest/389/submission/5878414\" title=\"Submission 5878414 by t_thirupathi\">5878414</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159883 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159883 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159883\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159909\" commentParentId=\"159883\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/9charles\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/119814/avatar/653156a3153bc2dd.jpg'/> </a>\n <div><a href=\"/profile/9charles\" title=\"Expert 9charles\" class=\"rated-user user-blue\">9charles</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 06:46\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159909\" href=\"?#comment-159909\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159883\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159909\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"119814\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159909\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can you explain it?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159909 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159909 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159909\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159907\" commentParentId=\"159881\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/k790alex\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/119882/avatar/4baeddca65b2b958.jpg'/> </a>\n <div><a href=\"/profile/k790alex\" title=\"Specialist k790alex\" class=\"rated-user user-cyan\">k790alex</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 06:28\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159907\" href=\"?#comment-159907\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159881\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159907\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"119882\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159907\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I don't know if this is a better way but I didt in the contest.</p><p>Start making a pile with the low strength and while possible, look for a box that can support at least 1 box, then at least 2 boxes, 3, etc, repeat it while you have boxes.</p><p>My solution: <a href=\"/contest/389/submission/5879464\" title=\"Submission 5879464 by k790alex\">5879464</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159907 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159907 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159907\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159914\" commentParentId=\"159907\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/YaleZ\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/24526/avatar/5b17db1affad55a5.jpg'/> </a>\n <div><a href=\"/profile/YaleZ\" title=\"Expert YaleZ\" class=\"rated-user user-blue\">YaleZ</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 07:38\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159914\" href=\"?#comment-159914\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159907\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159914\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"24526\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159914\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Greedy is also a nice solution.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159914 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159914 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159914\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159932\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/worfzyq\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/157364/avatar/8f104a361ed91be8.jpg'/> </a>\n <div><a href=\"/profile/worfzyq\" title=\"Expert worfzyq\" class=\"rated-user user-blue\">worfzyq</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 09:52\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159932\" href=\"?#comment-159932\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159932\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"157364\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159932\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>388C — Fox and Card Game This problem is good magic</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159932 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159932 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159932\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159935\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/orchidmajumder\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/63603/avatar/f8db3747466a7168.jpg'/> </a>\n <div><a href=\"/profile/orchidmajumder\" title=\"Specialist orchidmajumder\" class=\"rated-user user-cyan\">orchidmajumder</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 10:07\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159935\" href=\"?#comment-159935\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"159935\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"159935\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"7\"\r\n data-commentUserId=\"63603\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+7</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159935\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>hii everyone,in Div II E,I can't understand why the optimal play for JIRO is to take the bottom most card from the same pile from where CIEL is picking?should not it try to pick the maximum value among all bottom most card at it's every move??</p><p>Please someone explain why the strategy presented in the editorial is optimal.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159935 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159935 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159935\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159948\" commentParentId=\"159935\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Zzyzx\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/86049/avatar/c698ee674460e7eb.jpg'/> </a>\n <div><a href=\"/profile/Zzyzx\" title=\"Expert Zzyzx\" class=\"rated-user user-blue\">Zzyzx</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 13:07\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159948\" href=\"?#comment-159948\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159935\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159948\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"86049\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159948\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Ok, I'm afraid I do not have a rigorous proof for this. I'll just explain to you why I think it is right.</p><p>First of all, we need to understand that both Ciel and Jiro are smart. Now, whenever it is Ciel's turn, he will pick the "best pile" and try to take everything from that pile and then move on to the next "best pile". Jiro knows that his friend Ciel is smart, so he will try to stop him from taking everything. This can be done only if he picks from the same pile that Ciel does.</p><p>But your question is — what if there is a different pile whose bottom-most card is much better than the bottom-most card of the pile from which Ciel is picking right?</p><p>My answer to this is that, this situation will never arise. Because if there is such a pile, then Ciel will try to take that card in the first place and therefore, Ciel will be picking from the same pile that Jiro will want to pick from.</p><p>Am I making sense? Or is there a flaw in my argument?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159948 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159948 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159948\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159952\" commentParentId=\"159948\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/orchidmajumder\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/63603/avatar/f8db3747466a7168.jpg'/> </a>\n <div><a href=\"/profile/orchidmajumder\" title=\"Specialist orchidmajumder\" class=\"rated-user user-cyan\">orchidmajumder</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 13:32\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159952\" href=\"?#comment-159952\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159948\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159952\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"63603\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159952\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Yes I'm also thinking along the same line.Both are playing optimally and if Ciel is chosing any pile then jiro knows that this pile has better cards in the botttom half.So he won't choose ciel to take the advantage and vice versa.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159952 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159952 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159952\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159944\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hzyfr\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/hzyfr\" title=\"Expert hzyfr\" class=\"rated-user user-blue\">hzyfr</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 12:27\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159944\" href=\"?#comment-159944\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159944\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"129936\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159944\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I have a different idea on D div1 <a href=\"/contest/388/problem/D\" title=\"Codeforces Round 228 (Div. 1)\">388D - Fox and Perfect Sets</a> but I failed on getting some relations in one step.</p><p>Let <em>M</em> be the maximum element in set <em>S</em> . Then if <em>S</em> is a perfect set, its elements should have all bits equals <em>0</em> on positions in <em>M's</em> binary representation(otherwise there must exist another element bigger than <em>M</em>). So let <em>cnt</em> = (number of 1's in binary repersentation of <em>M</em>), then the number of perfect sets which has <em>M</em> as its greatest element is determined by <em>cnt</em> . Well, this is the step I can't come up with a solution(actually the target is to find the number of perfect sets which has <code>2^cnt-1</code> as its greatest element).</p><p>Then the last step is simple. We can apply something like doubling algorithm on the problem.</p><p>We are asked to find the number of perfect sets with all the elements not greater than <em>N</em> . Let's suppose <em>N+1</em> is a power of 2 then its easy to calculate how many numbers not greater than <em>N</em> has <em>cnt</em> = 1,2,...m where m is the length of <em>N</em> in binary representation. That's just simple combinatoric number <em>C(n,i) (1<=i<=n)</em> . And if we have done the previous step, it's easy to get the result.</p><p>Then think about common cases of <em>N</em> . Let's take the highest bit of N and since all above bits are determined, the number of 1's will just add a constant value. So calculate this part and subtract that highest bit of <em>N</em> and do the same thing on remaining value of <em>N</em> , until <em>N=0</em> . At that time we will get the correct answer. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159944 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159944 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159944\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159945\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/rexdf\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/23738/avatar/797fa665fbe1ca78.jpg'/> </a>\n <div><a href=\"/profile/rexdf\" title=\"Specialist rexdf\" class=\"rated-user user-cyan\">rexdf</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 12:36\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159945\" href=\"?#comment-159945\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159945\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"23738\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159945\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>dp[1] = 1, dp[v] = sum{dp[t] | dist(1,t) = dist(1,v) — 1}, then dp[2] is our answer. What's v means? what's '|' means? What's dp[v] means?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159945 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159945 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159945\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159949\" commentParentId=\"159945\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/sancho\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/85894/avatar/e31a4b24327c1000.jpg'/> </a>\n <div><a href=\"/profile/sancho\" title=\"Candidate Master sancho\" class=\"rated-user user-violet\">sancho</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 13:10\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159949\" href=\"?#comment-159949\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159945\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159949\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"85894\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159949\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>v — vertex, answer for which we are getting at this moment, | — means "such as", dp[v] — number of ways from 1 vertex to this one</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159949 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159949 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159949\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159947\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lol12\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/lol12\" title=\"Specialist lol12\" class=\"rated-user user-cyan\">lol12</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 13:04\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159947\" href=\"?#comment-159947\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159947\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"10\"\r\n data-commentUserId=\"152356\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+10</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159947\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can someone please explain solution of Div2-D. Thanx</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159947 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159947 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159947\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"160020\" commentParentId=\"159947\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/YaleZ\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/24526/avatar/5b17db1affad55a5.jpg'/> </a>\n <div><a href=\"/profile/YaleZ\" title=\"Expert YaleZ\" class=\"rated-user user-blue\">YaleZ</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/05/2014 07:07\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-160020\" href=\"?#comment-160020\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159947\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"160020\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"9\"\r\n data-commentUserId=\"24526\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+9</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-160020\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>You can think about binnary. Such as (13)10=(1101)2=((1+(2+0)*2)+1)*2+1</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-160020 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-160020 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-160020\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"469976\" commentParentId=\"159947\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/roll_no_1\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/631859/avatar/36d157f91f64fe7f.jpg'/> </a>\n <div><a href=\"/profile/roll_no_1\" title=\"Master roll_no_1\" class=\"rated-user user-orange\">roll_no_1</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Nov/09/2018 17:27\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-469976\" href=\"?#comment-469976\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159947\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"469976\" revisionCount=\"4\" revision=\"4\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">4</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"469976\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"631859\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-469976\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Here's my implementation of the editorialist's explanation of Div-2 D / Div-1 B: <a href=\"/contest/388/submission/45480077\" title=\"Submission 45480077 by roll_no_1\">45480077</a>. I implemented the layers as [1], [1, 1], [2, 1, 1], [4, 2, 1, 1] and so on.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-469976 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-469976 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-469976\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159967\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/BENYAM1N\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/84938/avatar/d2ae2657d8898e38.jpg'/> </a>\n <div><a href=\"/profile/BENYAM1N\" title=\"Master BENYAM1N\" class=\"rated-user user-orange\">BENYAM1N</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 15:51\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159967\" href=\"?#comment-159967\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159967\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"13\"\r\n data-commentUserId=\"84938\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+13</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159967\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Very good contest and nice editorial. Hope from now on I see more contests from you.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159967 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159967 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159967\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159984\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/kojak_\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/57722/avatar/38990eea59bc188e.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/kojak_\" title=\"Newbie kojak_\" class=\"rated-user user-gray\">kojak_</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 18:34\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159984\" href=\"?#comment-159984\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159984\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"57722\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159984\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Did anyone come up with a DP solution for Div.2 C/ Div.1 A?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159984 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159984 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159984\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"160012\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/IgorKoval\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/51322/avatar/afc854fff49f072a.jpg'/> </a>\n <div><a href=\"/profile/IgorKoval\" title=\"Candidate Master IgorKoval\" class=\"rated-user user-violet\">IgorKoval</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 23:17\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-160012\" href=\"?#comment-160012\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"160012\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"11\"\r\n data-commentUserId=\"51322\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+11</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-160012\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Объясните, пожалуйста, разбор задачи "388D — Fox and Perfect Sets" на пальцах. Как-нибудь без Гаусса и базисов. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-160012 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-160012 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-160012\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"160016\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Mr.ink\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Mr.ink\" title=\"Expert Mr.ink\" class=\"rated-user user-blue\">Mr.ink</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/05/2014 01:08\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-160016\" href=\"?#comment-160016\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"160016\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"128876\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-160016\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>fox and card games is a great problem.thanks!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-160016 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-160016 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-160016\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"160037\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/yaswanth\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/yaswanth\" title=\"Specialist yaswanth\" class=\"rated-user user-cyan\">yaswanth</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/05/2014 18:38\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-160037\" href=\"?#comment-160037\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"160037\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"9\"\r\n data-commentUserId=\"96196\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+9</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-160037\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can anyone explain div2 C question? I did not understand the editorial.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-160037 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-160037 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-160037\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"160063\" commentParentId=\"160037\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/YaleZ\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/24526/avatar/5b17db1affad55a5.jpg'/> </a>\n <div><a href=\"/profile/YaleZ\" title=\"Expert YaleZ\" class=\"rated-user user-blue\">YaleZ</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/06/2014 05:46\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-160063\" href=\"?#comment-160063\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-160037\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"160063\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"24526\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-160063\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>s[i]>=i/k -> k*s[i]>=i There are i boxes' strength smaller than i-th box. So we need to check if the boxes before i-th can be held.</p><p>(I don't know whether I have understood correctly...)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-160063 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-160063 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-160063\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"160053\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/yada\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/142663/avatar/49901b54d1c5f019.jpg'/> </a>\n <div><a href=\"/profile/yada\" title=\"Candidate Master yada\" class=\"rated-user user-violet\">yada</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/05/2014 23:24\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-160053\" href=\"?#comment-160053\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"160053\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"142663\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-160053\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Great Problem! I really enjoy it.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-160053 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-160053 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-160053\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"364019\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lnzva\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/305672/avatar/cf6c09a214141751.jpg'/> </a>\n <div><a href=\"/profile/lnzva\" title=\"Expert lnzva\" class=\"rated-user user-blue\">lnzva</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/02/2017 22:06\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-364019\" href=\"?#comment-364019\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"364019\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"364019\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"305672\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-364019\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In 388C, I'm having a hard time understanding why Jiro's optimal strategy would be to pick the pile Ciel just picked. Why not pick a pile which has a better bottom part than the one Ciel is picking? According to some comments, Ciel would then pick from the second pile-what if another pile has a much better top part? Could someone please help? I saw this problem first 6 months ago, and I had a hard time understanding why this greedy is correct; I saw this problem again today and am having trouble with it again, with no progress.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-364019 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-364019 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-364019\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"647866\" commentParentId=\"364019\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/_wzx27\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1458283/avatar/7d77b62012ae2398.jpg'/> </a>\n <div><a href=\"/profile/_wzx27\" title=\"Candidate Master _wzx27\" class=\"rated-user user-violet\">_wzx27</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/22/2020 18:33\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-647866\" href=\"?#comment-647866\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-364019\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"647866\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1458283\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-647866\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Let's consider such a two-piles situation:</p><p><em>111100</em></p><p><em>001111</em></p><p>is better for Ciel.</p><p>"1" means this card is picked by Ciel,while "0" by Jiro.</p><p>We know that better for Ciel means worse for Jiro.</p><p>So if</p><p><em>111100</em></p><p><em>001111</em></p><p>is better than</p><p><em>111000</em></p><p><em>000111</em></p><p>for Ciel.</p><p>Then when Ciel picked the <strong>first three cards</strong> from <strong>pile 1</strong>,Jiro can just pick the <strong>last three cards</strong> from <strong>pile 1</strong> and finally lead to the result:</p><p><em>111000</em></p><p><em>000111</em></p><p>which is not better for Ciel.</p><p>Generally, if the final result is not balance(half from top and half from bottom) while balance is better than such result for Jiro, Jiro has the ability to adjust it to be balance.So do Ciel.</p><p>Therefore,it reaches balance.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-647866 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-647866 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-647866\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"407776\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/madhur4127\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/568692/avatar/c7d62cc23c758819.jpg'/> </a>\n <div><a href=\"/profile/madhur4127\" title=\"Specialist madhur4127\" class=\"rated-user user-cyan\">madhur4127</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/15/2018 13:06\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-407776\" href=\"?#comment-407776\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"407776\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"568692\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-407776\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>@<a class=\"rated-user user-red\" href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\">cgy4ever</a>, github link shows 404 error(Page not found). Kindly fix it.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-407776 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-407776 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-407776\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"416354\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/introverted\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/657339/avatar/7a6edb1ecc1d3e09.jpg'/> </a>\n <div><a href=\"/profile/introverted\" title=\"Expert introverted\" class=\"rated-user user-blue\">introverted</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/23/2018 11:48\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-416354\" href=\"?#comment-416354\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"416354\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"657339\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-416354\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I solved the DIV1B problem with simple recursion and Divide and Conquer.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-416354 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-416354 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-416354\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"427890\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Nuu\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/652228/avatar/d59867d6477379dc.jpg'/> </a>\n <div><a href=\"/profile/Nuu\" title=\"Candidate Master Nuu\" class=\"rated-user user-violet\">Nuu</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/01/2018 22:33\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-427890\" href=\"?#comment-427890\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"427890\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"652228\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-427890\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can anyone give me some examples of the similar problems to DivC?? I think this problem is very nice for train brain xD</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-427890 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-427890 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-427890\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"629609\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/The_Alchemist\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1275181/avatar/662970aa05d3dfc5.jpg'/> </a>\n <div><a href=\"/profile/The_Alchemist\" title=\"Expert The_Alchemist\" class=\"rated-user user-blue\">The_Alchemist</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/25/2020 21:47\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-629609\" href=\"?#comment-629609\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"629609\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1275181\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-629609\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I know I am very late but can someone pls explain to me div 2C/div1A. Thanks in advance... </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-629609 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-629609 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-629609\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"641010\" commentParentId=\"629609\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/kstheking\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1160931/avatar/e144fc7b0fdb90b1.jpg'/> </a>\n <div><a href=\"/profile/kstheking\" title=\"Pupil kstheking\" class=\"rated-user user-green\">kstheking</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/13/2020 14:47\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-641010\" href=\"?#comment-641010\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-629609\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"641010\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1160931\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-641010\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p><a href=\"https://codeforces.com/contest/388/submission/83605110\">https://codeforces.com/contest/388/submission/83605110</a> Here you go, if you don't get it feel free to ask</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-641010 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-641010 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-641010\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"644488\" commentParentId=\"641010\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/tanisha_\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/tanisha_\" title=\"Newbie tanisha_\" class=\"rated-user user-gray\">tanisha_</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/18/2020 15:26\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-644488\" href=\"?#comment-644488\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-641010\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"644488\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1500127\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-644488\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>is this any algorithm</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-644488 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-644488 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-644488\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"647627\" commentParentId=\"644488\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/kstheking\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1160931/avatar/e144fc7b0fdb90b1.jpg'/> </a>\n <div><a href=\"/profile/kstheking\" title=\"Pupil kstheking\" class=\"rated-user user-green\">kstheking</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/22/2020 08:40\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-647627\" href=\"?#comment-647627\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-644488\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"647627\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"647627\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1160931\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-647627\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Well you can call it a greedy algorithm, when we try to apply greedy by placing the heaviest block in bottom, a little problem occurs because of blocks of same strength for example in case of 10 2 2 1 1 0 0<br />If you try to apply greedy by choosing the strongest block<br />10 2 2 1<br />1 0<br />0<br />= 3 heaps<br />Which is wrong answer as sometimes we lose opportunity to create lesser heaps, as in this case if we use the second 2 to make another heap we can do better<br />10 2 1 0<br />2 1 0<br />= 2 heaps<br />So I apply greedy in the reverse direction by picking the smallest strength brick and placing below it the next smallest brick, this way the optimal number of heaps will be formed as in above example<br />choose 0, then you need >= 1, choose 1, then you need >= 2, choose 2, then you need >= 3 choose 10<br />repeat until you have chosen all the bricks<br />If you don't get anything, feel free to ask :) </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-647627 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-647627 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-647627\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"702677\" commentParentId=\"647627\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/breddreamer\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/853067/avatar/240684624b57996.jpg'/> </a>\n <div><a href=\"/profile/breddreamer\" title=\"Newbie breddreamer\" class=\"rated-user user-gray\">breddreamer</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/27/2020 13:01\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-702677\" href=\"?#comment-702677\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-647627\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"702677\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"853067\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-702677\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks, It helped me to understand your solution idea. And finally, I solved this one.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-702677 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-702677 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-702677\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"649225\" commentParentId=\"641010\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/The_Alchemist\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1275181/avatar/662970aa05d3dfc5.jpg'/> </a>\n <div><a href=\"/profile/The_Alchemist\" title=\"Expert The_Alchemist\" class=\"rated-user user-blue\">The_Alchemist</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/24/2020 12:04\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-649225\" href=\"?#comment-649225\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-641010\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"649225\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1275181\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-649225\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>thank you.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-649225 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-649225 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-649225\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n <br/>\r\n\r\n<div id=\"editBox-10700\" style=\"width:50em;display:none;\">\r\n <div class=\"previewBody\" style=\"border: 1px solid #d4d4d4; margin-bottom: 0.5em; padding: 0.25em; display:none;\"> </div>\r\n <div style=\"width: 1px\"> </div>\r\n <div class=\"commentLocale\" style=\"position: relative; top: 0.5em;left:4px;display: none;\">\r\n <input type=\"radio\" name=\"locale\" value=\"en\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In English</span>\r\n <input style=\"margin-left:1em\" type=\"radio\" name=\"locale\" value=\"ru\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In Russian</span>\r\n </div>\r\n <textarea data-drafts-id=\"CommentReplyFrame\" class=\"wysiwyg\" name=\"editContent\" rows=\"20\" style=\"width:99%;\"></textarea>\r\n <div class=\"error error__content\"></div>\r\n <div style=\"text-align:center;\">\r\n <input type=\"button\" name=\"preview\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Preview\"/>\r\n <input type=\"button\" name=\"save\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Save\"/>\r\n </div>\r\n</div>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n\r\nvar firstPreview10700 = true;\r\nvar lastPreviewContent10700 = '';\r\n\r\nif (!window.moveCommentRevision) {\r\n moveCommentRevision = function(e, dir) {\r\n var p = e.parent();\r\n var revisionCount = parseInt(p.attr(\"revisionCount\"));\r\n var revision = parseInt(p.attr(\"revision\"));\r\n var next = revision + dir;\r\n var commentId = p.attr(\"commentId\");\r\n if (next >= 1 && next <= revisionCount) {\r\n $.post(\r\n \"/data/comment-data\",\r\n {action: \"revision\", commentId: commentId, revision: next},\r\n function(json) {\r\n if (json.success == \"true\") {\r\n var parentDiv = e;\r\n\r\n while (parentDiv !== null && (parentDiv[0].nodeName.toLowerCase() !== \"td\" || !parentDiv.hasClass(\"right\"))) {\r\n parentDiv = parentDiv.parent();\r\n }\r\n\r\n if (parentDiv === null) {\r\n return;\r\n }\r\n\r\n parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\").html(json.content);\r\n Codeforces.setupSpoilers(parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\"));\r\n p.attr(\"revision\", next);\r\n p.find(\"span.revision\").text(next);\r\n if (next == 1) {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"visible\");\r\n }\r\n if (next == revisionCount) {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"visible\");\r\n }\r\n\r\n window.updateTypography();\r\n MathJax.Hub.Typeset();\r\n } else {\r\n alert(e.error);\r\n }\r\n },\r\n \"json\"\r\n );\r\n }\r\n };\r\n}\r\n\r\n$(\"div[commentableId=10700] a.leftRevision\").click(function () {\r\n window.moveCommentRevision($(this), -1);\r\n return false;\r\n});\r\n\r\n$(\"div[commentableId=10700] a.rightRevision\").click(function () {\r\n window.moveCommentRevision($(this), +1);\r\n return false;\r\n});\r\n\r\n\r\n\r\n });\n </script>\n\r\n\r\n <script src=\"//codeforces.org/s/81027/js/swfobject-2.2.min.js\" type=\"text/javascript\"></script>\n <script src=\"//codeforces.org/s/81027/js/ftaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n if (window.evercookie) {\n var ec = new evercookie({\n history: false,\n silverlight: false,\n baseurl: '',\n asseturi: '/assets',\n phpuri: '/2fdcd78',\n pngPath: '/eps',\n etagPath: '/ees',\n cachePath: '/ecs'\n });\n\n var randomNumber = function () {\n return Math.random().toString(36).substr(2);\n };\n\n var randomToken = function () {\n return (randomNumber() + randomNumber()).substring(0, 18);\n };\n\n window._ftaa = \"\";\n\n ec.get(\"70a7c28f3de\", function (value) {\n window._ftaa = value;\n if (!window._ftaa) {\n window._ftaa = randomToken();\n ec.set(\"70a7c28f3de\", window._ftaa);\n }\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n } else {\n window._ftaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\n <script src=\"//codeforces.org/s/81027/js/bfaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n var fpCallback = function() {\n Fingerprint2.get({}, function(components) {\n window._bfaa = Fingerprint2.x64hash128(components.map(function (pair) { return pair.value }).join(), 31);\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n };\n if (typeof Fingerprint2 !== 'undefined') {\n if (window.requestIdleCallback) {\n requestIdleCallback(fpCallback)\n } else {\n setTimeout(fpCallback, 500)\n }\n } else {\n window._bfaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"a.new-root-comment\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n\r\n $(\".comment-table .reply a\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".vote-for-comment\").mouseover(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").mouseout(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").click(function () {\r\n var vote = $(this);\r\n var commentId = $(this).parent().attr(\"commentid\");\r\n var commentRating = $(this).parent().attr(\"data-commentRating\");\r\n var direction = $(this).attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n $.post(\"/data/comment/vote\", {commentId: commentId, _tta: Codeforces.tta(), vote: direction, commentRating: commentRating}, function(data) {\r\n if (direction != 0 && !ownComment && data[\"success\"] == \"true\") {\r\n vote.parent().find(\".vote-for-comment\").attr(\"voteDirection\", 0);\r\n if (direction == 1)\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n else {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.closest(\".CommentVoteFrame\").find(\".ComplaintFrame\").css(\"display\", \"inline-block\");\r\n }\r\n vote.find(\"img\").attr(\"popacity\", \"1.0\");\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n vote.parent().find(\".commentRating\").html(data[\"commentRating\"]);\r\n }\r\n Codeforces.showMessage(data[\"message\"]);\r\n }, \"json\");\r\n return false;\r\n });\r\n\r\n $(\".negative-comment-vote\").closest(\".comment-table\").addClass(\"comment-bad\");\r\n\r\n $(\".troll-comment-vote\").closest(\".comment\").css(\"display\", \"none\");\r\n\r\n $(\".too-negative-comment-vote\").closest(\".comment-table\").each(function () {\r\n var e = $(this);\r\n e.addClass(\"comment-too-bad\");\r\n var commentId = e.attr(\"commentId\");\r\n $(\"<div class='bad-comment-replacement ttypography'>The comment is hidden because of too negative feedback, click <a href=# class=show-bad-comment-link>here</a> to view it</div>\").appendTo(\r\n e.find(\".right\")\r\n );\r\n e.find(\".comment-content\").hide();\r\n e.find(\".show-bad-comment-link\").click(function () {\r\n e.find(\".comment-content\").show();\r\n e.find(\".bad-comment-replacement\").hide();\r\n return false;\r\n });\r\n });\r\n });\n </script>\n </div>\r\n\r\n <style type=\"text/css\">\r\n .new-comments-box {\r\n padding: 0.5em;\r\n width: 22px;\r\n font-size: 1.3rem;\r\n font-weight: bold !important;\r\n\r\n position: fixed;\r\n top: 40%;\r\n right: 0;\r\n opacity: 0.2;\r\n color: white;\r\n text-align: center;\r\n\r\n border: 1px solid #222;\r\n background-color: #888 !important;\r\n border-radius: 3px;\r\n -moz-border-radius: 3px;\r\n -webkit-border-radius: 3px;\r\n }\r\n\r\n .new-comments-box:hover {\r\n opacity: 1;\r\n }\r\n\r\n .new-comments-box .dir:hover {\r\n background: #3B5998 !important;\r\n cursor: pointer;\r\n }\r\n </style>\r\n\r\n <div class=\"new-comments-box\" data-position=\"outside\" data-index=\"-1\" style=\"display: none;\">\r\n <div class=\"up dir\" title=\"Ctrl+Up\">↑<hr/>\r\n </div>\r\n <div class=\"info\" title=\"New comments\"></div>\r\n <div class=\"down dir\" title=\"Ctrl+Down\">\r\n <hr/>↓\r\n </div>\r\n </div>\r\n\r\n <script>\r\n $(\".show-archived-checkbox\").change(function () {\r\n const checked = $(this).is(\":checked\");\r\n $.post(\"/data/comment-data\", {action: \"setShowArchived\", checked}, function (json) {\r\n if (json[\"success\"] !== \"true\") {\r\n alert(json[\"error\"]);\r\n } else {\r\n if (checked) {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are now displayed\")\r\n } else {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are no longer displayed\")\r\n }\r\n }\r\n });\r\n return false;\r\n });\r\n\r\n function gotoComment(direction) {\r\n var box = $(\".new-comments-box\");\r\n var index = parseInt(box.attr(\"data-index\"));\r\n if (index == -1)\r\n index = 0;\r\n else\r\n index = Math.max(0, Math.min(parseInt(box.find(\".info\").text()) - 1, index + direction));\r\n box.attr(\"data-index\", index);\r\n var comment = $($(\".comment .highlight-blue[commentId]\").get(index));\r\n $('html, body').animate({\r\n 'scrollTop': Math.max(0, comment.offset().top - ($(window).height() - comment.height()) / 2)\r\n });\r\n return false;\r\n }\r\n\r\n $(\".new-comments-box .down\").click(function () {\r\n return gotoComment(1);\r\n });\r\n\r\n $(\".new-comments-box .up\").click(function () {\r\n return gotoComment(-1);\r\n });\r\n\r\n $(document).keydown(function (e) {\r\n var code = (e.keyCode ? e.keyCode : e.which);\r\n if (e.ctrlKey) {\r\n if (code == 38 || code == 40) {\r\n gotoComment(code - 39);\r\n }\r\n }\r\n });\r\n\r\n var newCommentCount = $(\".comment .highlight-blue[commentId]\").length;\r\n if (newCommentCount > 0) {\r\n $(\".new-comments-box .info\").text(newCommentCount);\r\n $(\".new-comments-box\").show();\r\n }\r\n\r\n $('table.comment-table').mouseenter(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").addClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n\r\n $('table.comment-table').mouseleave(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").removeClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n </script>\r\n\r\n\r\n\r\n <script>\r\n function adjustTopicComplainFrames() {\r\n let topicIds = [];\r\n\r\n $(\".has-topic-id\").each(function () {\r\n const $this = $(this);\r\n const topicId = $this.attr(\"topicId\");\r\n if (topicId) {\r\n topicIds.push(topicId);\r\n }\r\n });\r\n\r\n $.post(\"/data/topics\", {\r\n action: \"findComplainableTopicIds\",\r\n topicIds: topicIds.join(\",\")\r\n }, function (json) {\r\n if (json[\"success\"] === \"true\") {\r\n for (const topicId of json[\"complainableTopicIds\"].split(\",\")) {\r\n $(\".has-topic-id[topicId=\" + topicId + \"]\").each(function () {\r\n $(this).find(\".meta .ComplaintFrame\").css(\"display\", \"inline-block\");\r\n });\r\n }\r\n }\r\n }, \"json\");\r\n }\r\n\r\n $(function () {\r\n adjustTopicComplainFrames();\r\n })\r\n </script>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-10684\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 10684, _tta: Codeforces.tta(), topicRevisionId: 36670, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-10684\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 10684, _tta: Codeforces.tta(), topicRevisionId: 36670, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n </div>\r\n </div>\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 22:13:07</span> (h1).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/81027/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/81027/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/81027/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/81027/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-81027.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'812875a2ab4016f4',t:'MTY5NjcwNTk4Ny4yMjQwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"}}},{"rowIdx":1965,"cells":{"problem_id":{"kind":"string","value":"389C"},"contest":{"kind":"string","value":"389"},"problem":{"kind":"string","value":"C"},"lang":{"kind":"string","value":"en"},"problem_title":{"kind":"string","value":"C. Fox and Box Accumulation"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">C. Fox and Box Accumulation</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Fox Ciel has <span class=\"tex-span\"><i>n</i></span> boxes in her room. They have the same size and weight, but they might have different strength. The <span class=\"tex-span\"><i>i</i></span>-th box can hold at most <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span> boxes on its top (we'll call <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span> the strength of the box). </p><p>Since all the boxes have the same size, Ciel cannot put more than one box directly on the top of some box. For example, imagine Ciel has three boxes: the first has strength 2, the second has strength 1 and the third has strength 1. She cannot put the second and the third box simultaneously directly on the top of the first one. But she can put the second box directly on the top of the first one, and then the third box directly on the top of the second one. We will call such a construction of boxes a <span class=\"tex-font-style-it\">pile</span>.</p><center><img class=\"tex-graphics\" src=\"https://espresso.codeforces.com/97f4897ba81d44a26f9d9efcf7fc3cb427ba885b.png\" style=\"max-width: 100.0%;max-height: 100.0%;\"/></center><p>Fox Ciel wants to construct piles from all the boxes. Each pile will contain some boxes from top to bottom, and there cannot be more than <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span> boxes on the top of <span class=\"tex-span\"><i>i</i></span>-th box. What is the minimal number of piles she needs to construct?</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains an integer <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">1 ≤ <i>n</i> ≤ 100</span>). The next line contains <span class=\"tex-span\"><i>n</i></span> integers <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">1</sub>, <i>x</i><sub class=\"lower-index\">2</sub>, ..., <i>x</i><sub class=\"lower-index\"><i>n</i></sub></span> (<span class=\"tex-span\">0 ≤ <i>x</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 100</span>).</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Output a single integer — the minimal possible number of piles.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>3<br/>0 0 10<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>2<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>5<br/>0 1 2 3 4<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>4<br/>0 0 0 0<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>4<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>9<br/>0 1 0 2 0 1 1 2 10<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>3<br/></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>In example 1, one optimal way is to build 2 piles: the first pile contains boxes 1 and 3 (from top to bottom), the second pile contains only box 2.</p><center><img class=\"tex-graphics\" src=\"https://espresso.codeforces.com/8cc9a4fa88a6ae1c5f8d28bad6f46baf9fb52988.png\" style=\"max-width: 100.0%;max-height: 100.0%;\"/></center><p>In example 2, we can build only 1 pile that contains boxes 1, 2, 3, 4, 5 (from top to bottom).</p><center><img class=\"tex-graphics\" src=\"https://espresso.codeforces.com/51e8d6552ca61c237a2e7df55cef2cd62741f5c4.png\" style=\"max-width: 100.0%;max-height: 100.0%;\"/></center></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"f120500e133fbbbb0d3dc70e182486d8\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - C - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"f7b10a37dac6b25fba992a730cfa3b90bd8afecf\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - C - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/73366/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/73366/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/73366/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/73366/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/73366/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/73366/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/73366/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/73366/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/73366/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/73366/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/73366/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/73366/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/73366/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/73366/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/sidebar-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/a037fe51637846d9c7c725713cd840ea/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='f120500e133fbbbb0d3dc70e182486d8'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/73366/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/73366/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fcontest%2F389%2Fproblem%2FC%3Flocale%3Den\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"current\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='f120500e133fbbbb0d3dc70e182486d8'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:100%;\"><a style=\"color: black\" href=\"/contest/389\">Codeforces Round 228 (Div. 2)</a></th>\n </tr>\n <tr>\n <td class=\"left bottom\" colspan=\"1\"><span class=\"contest-state-phase\">Finished</span></td>\n </tr>\n </tbody>\n </table>\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Practice?\n <div class=\"top-links\">\n </div>\n </div>\n<div>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Want to solve the contest problems after the official contest ends? Just register for practice and you will be able to submit solutions.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"\" method=\"post\"><input type='hidden' name='csrf_token' value='f120500e133fbbbb0d3dc70e182486d8'/>\r\n <input type=\"hidden\" name=\"action\" value=\"registerForPractice\"/>\r\n <input type=\"submit\" name=\"submit\" value=\"Register for practice\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div> \r\n</div>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox ContestVirtualFrame borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Virtual participation <i class=\"sidebar-caption-icon las la-angle-down\"></i>\r\n\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\" \"\r\n\r\n data-page-url=\"/data/sidebarFrames\"\r\n\r\n>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests.\n\nIf you've seen these problems, a virtual contest is not for you - solve these problems in the archive.\n\nIf you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.\n\nNever use someone else's code, read the tutorials or communicate with other person during a virtual contest.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"/contest/389/virtual\" method=\"get\">\r\n <input type=\"submit\" name=\"submit\" value=\"Start virtual contest\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div>\r\n</div>\r\n <script>\r\n $(function () {\r\n $(\".ContestVirtualFrame .sidebar-caption-icon\").click(function() {\r\n $(this).toggleClass(\"la-angle-down la-angle-right\");\r\n const $target = $(this).parent().next();\r\n $target.toggle();\r\n const dataPageUrl = $target.attr(\"data-page-url\");\r\n const collapsed = $(this).hasClass(\"la-angle-right\");\r\n const params = {\r\n action: \"setCollapsed\",\r\n sidebarFrameSimpleClassName: \"ContestVirtualFrame\",\r\n collapsed\r\n };\r\n $.each($target[0].attributes, function(i, a) {\r\n const name = a.name;\r\n if (name.startsWith(\"data-extra-key-\")) {\r\n const key = a.value;\r\n const keyIndex = parseInt(name.substring(\"data-extra-key-\".length));\r\n const value = $target.attr(\"data-extra-value-\" + keyIndex);\r\n params[key] = value;\r\n }\r\n });\r\n $.post(dataPageUrl, params, function (result) {\r\n if (result[\"success\"] !== \"true\") {\r\n Codeforces.showMessage(\"Failed to save collapsed state.\");\r\n }\r\n }, \"json\");\r\n return false;\r\n });\r\n })\r\n </script>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Problem tags\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Binary search\">\r\n binary search\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Dynamic programming\">\r\n dp\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Greedy algorithms\">\r\n greedy\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Difficulty\">\r\n *1400\r\n</span>\r\n </div>\n <div style=\"clear:both;text-align:right;font-size:1.1rem;\">\r\n <span title=\"Please login into the Codeforces\" class=\"notice\">No tag edit access</span>\r\n </div>\r\n</div>\r\n </div>\n\r\n<form id=\"addTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='f120500e133fbbbb0d3dc70e182486d8'/>\r\n <input name=\"action\" type=\"hidden\" value=\"addTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"6402\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<form id=\"removeTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='f120500e133fbbbb0d3dc70e182486d8'/>\r\n <input name=\"action\" type=\"hidden\" value=\"removeTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"6402\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<script type=\"text/javascript\">\r\n $(\".tag-box img\").click(function () {\r\n var tagName = $(this).attr(\"value\");\r\n Codeforces.confirm(\"Are you sure you want to remove this tag?\", function () {\r\n $(\"#removeTagForm input[name=tagName]\").val(tagName);\r\n $(\"#removeTagForm\").submit();\r\n }, function () {\r\n }, \"Yes\", \"No\");\r\n });\r\n\r\n $(\"#addTagLink\").click(function () {\r\n $(this).hide();\r\n $(\"#addTagLabel\").show();\r\n return false;\r\n });\r\n\r\n $(\"#addTagSelect\").change(function () {\r\n var tagName = $(this).val();\r\n if (tagName === \"\") {\r\n $(\"#addTagLabel\").hide();\r\n $(\"#addTagLink\").show();\r\n } else {\r\n $(\"#addTagForm input[name=tagName]\").val(tagName);\r\n $(\"#addTagForm\").submit();\r\n }\r\n });\r\n</script>\r\n\r\n<style type=\"text/css\">\r\n#new-resource-form tr td {\r\npadding-top: 0.5em;\r\n}\r\n#new-resource-form input:not([type=\"submit\"]) {\r\nfont-size: 0.8em;\r\n}\r\n#new-resource-form select {\r\nfont-size: 0.8em;\r\n}\r\n.new-resource-error {\r\nfont-size: 0.8em;\r\n}\r\n.resource-locale {\r\ncolor: #666;\r\nfont-family: Consolas, \"Andale Mono WT\", \"Andale Mono\", \"Lucida Console\", \"Lucida Sans Typewriter\", \"DejaVu Sans Mono\", \"Bitstream Vera Sans Mono\", \"Liberation Mono\", \"Nimbus Mono L\", Monaco, \"Courier New\", Courier, monospace;\r\n}\r\n</style>\r\n<div class=\"roundbox sidebox sidebar-menu borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Contest materials\n<div class=\"top-links\">\n</div>\n</div>\n<ul>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/10605\" title=\"Codeforces Round #228\" target=\"_blank\">Codeforces Round #228</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"2189:2190\" resourceName=\"Announcement\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/10629\" title=\"Codeforces Round #228 — Editorial\" target=\"_blank\">Tutorial <span class=\"resource-locale\">(en)</span></a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"2191\" resourceName=\"Codeforces Round #228 — Editorial\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n</ul>\r\n</div></div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li class=\"current selectedLava\"><a\r\n href=\"/contest/389\">Problems</a></li>\r\n <li><a\r\n href=\"/contest/389/submit\">Submit Code</a></li>\r\n <li><a\r\n href=\"/contest/389/my\">My Submissions</a></li>\r\n <li><a\r\n href=\"/contest/389/status\">Status</a></li>\r\n <li><a\r\n href=\"/contest/389/hacks\">Hacks</a></li>\r\n <li><a\r\n href=\"/contest/389/room/1\">Room</a></li>\r\n <li><a\r\n href=\"/contest/389/standings\">Standings</a></li>\r\n <li><a\r\n href=\"/contest/389/customtest\">Custom Invocation</a></li>\r\n</ul>\r\n</div>\n\r\n <style>\r\n #facebox .content:has(.diff-popup) {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n }\r\n\r\n .testCaseMarker {\r\n position: absolute;\r\n font-weight: bold;\r\n font-size: 1rem;\r\n }\r\n\r\n .diff-popup {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n display: none;\r\n overflow: auto;\r\n }\r\n\r\n .input-output-copier {\r\n font-size: 1.2rem;\r\n float: right;\r\n color: #888 !important;\r\n cursor: pointer;\r\n border: 1px solid rgb(185, 185, 185);\r\n padding: 3px;\r\n margin: 1px;\r\n line-height: 1.1rem;\r\n text-transform: none;\r\n }\r\n\r\n .input-output-copier:hover {\r\n background-color: #def;\r\n }\r\n\r\n .test-explanation textarea {\r\n width: 100%;\r\n height: 1.5em;\r\n }\r\n\r\n .pending-submission-message {\r\n color: darkorange !important;\r\n }\r\n </style>\r\n <script>\r\n const OPENING_SPACE = String.fromCharCode(1001);\r\n const CLOSING_SPACE = String.fromCharCode(1002);\r\n\r\n const nodeToText = function (node, pre) {\r\n let result = [];\r\n\r\n if (node.tagName === \"SCRIPT\" || node.tagName === \"math\"\r\n || (node.classList && node.classList.contains(\"input-output-copier\")))\r\n return [];\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(OPENING_SPACE);\r\n }\r\n\r\n if (node.nodeType === Node.TEXT_NODE) {\r\n let s = node.textContent;\r\n if (!pre) {\r\n s = s.replace(/\\s+/g, \" \");\r\n }\r\n if (s.length > 0) {\r\n result.push(s);\r\n }\r\n }\r\n\r\n if (pre && node.tagName === \"BR\") {\r\n result.push(\"\\n\");\r\n }\r\n\r\n node.childNodes.forEach(function (child) {\r\n result.push(nodeToText(child, node.tagName === \"PRE\").join(\"\"));\r\n });\r\n\r\n if (node.tagName === \"DIV\"\r\n || node.tagName === \"P\"\r\n || node.tagName === \"PRE\"\r\n || node.tagName === \"UL\"\r\n || node.tagName === \"LI\"\r\n ) {\r\n result.push(\"\\n\");\r\n }\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(CLOSING_SPACE);\r\n }\r\n\r\n return result;\r\n }\r\n\r\n const isSpecial = function (c) {\r\n return c === ',' || c === '.' || c === ';' || c === ')' || c === ' ';\r\n }\r\n\r\n const convertStatementToText = function(statmentNode) {\r\n const text = nodeToText(statmentNode, false).join(\"\").replace(/ +/g, \" \").replace(/\\n\\n+/g, \"\\n\\n\");\r\n let result = [];\r\n for (let i = 0; i < text.length; i++) {\r\n const c = text.charAt(i);\r\n if (c === OPENING_SPACE) {\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"C\" data-uuid=\"ps_9f3d61a2421b05ccbfce81fed0f593fae8ae25e0\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">C. Fox and Box Accumulation</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Fox Ciel has <span class=\"tex-span\"><i>n</i></span> boxes in her room. They have the same size and weight, but they might have different strength. The <span class=\"tex-span\"><i>i</i></span>-th box can hold at most <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span> boxes on its top (we'll call <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span> the strength of the box). </p><p>Since all the boxes have the same size, Ciel cannot put more than one box directly on the top of some box. For example, imagine Ciel has three boxes: the first has strength 2, the second has strength 1 and the third has strength 1. She cannot put the second and the third box simultaneously directly on the top of the first one. But she can put the second box directly on the top of the first one, and then the third box directly on the top of the second one. We will call such a construction of boxes a <span class=\"tex-font-style-it\">pile</span>.</p><center><img class=\"tex-graphics\" src=\"https://espresso.codeforces.com/97f4897ba81d44a26f9d9efcf7fc3cb427ba885b.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></center><p>Fox Ciel wants to construct piles from all the boxes. Each pile will contain some boxes from top to bottom, and there cannot be more than <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span> boxes on the top of <span class=\"tex-span\"><i>i</i></span>-th box. What is the minimal number of piles she needs to construct?</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains an integer <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">1 ≤ <i>n</i> ≤ 100</span>). The next line contains <span class=\"tex-span\"><i>n</i></span> integers <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">1</sub>, <i>x</i><sub class=\"lower-index\">2</sub>, ..., <i>x</i><sub class=\"lower-index\"><i>n</i></sub></span> (<span class=\"tex-span\">0 ≤ <i>x</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 100</span>).</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Output a single integer — the minimal possible number of piles.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>3<br />0 0 10<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>2<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>5<br />0 1 2 3 4<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>4<br />0 0 0 0<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>4<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>9<br />0 1 0 2 0 1 1 2 10<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>3<br /></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>In example 1, one optimal way is to build 2 piles: the first pile contains boxes 1 and 3 (from top to bottom), the second pile contains only box 2.</p><center><img class=\"tex-graphics\" src=\"https://espresso.codeforces.com/8cc9a4fa88a6ae1c5f8d28bad6f46baf9fb52988.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></center><p>In example 2, we can build only 1 pile that contains boxes 1, 2, 3, 4, 5 (from top to bottom).</p><center><img class=\"tex-graphics\" src=\"https://espresso.codeforces.com/51e8d6552ca61c237a2e7df55cef2cd62741f5c4.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></center></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=C]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== statementText) {\r\n $problem.find(\".diff-notifier\").show();\r\n\r\n $problem.find(\".diff-notifier-close\").click(function() {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n $problem.find(\".diff-notifier\").hide();\r\n });\r\n\r\n $problem.find(\"a.view-changes\").click(function() {\r\n $.post(\"/data/diff\", {action: \"getDiff\", a: previousStatementText, b: statementText}, function (result) {\r\n if (result[\"success\"] === \"true\") {\r\n Codeforces.facebox(\".diff-popup\", \"//codeforces.org/s/73366\");\r\n $(\"#facebox .diff-popup\").html(result[\"diff\"]);\r\n }\r\n }, \"json\");\r\n });\r\n }\r\n } else {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n }\r\n });\r\n });\r\n </script>\r\n\r\n\r\n<script type=\"text/javascript\">\r\n $(document).ready(function () {\r\n window.changedTests = new Set();\r\n\r\n function endsWith(string, suffix) {\r\n return string.indexOf(suffix, string.length - suffix.length) !== -1;\r\n }\r\n\r\n const inputFileDiv = $(\"div.input-file\");\r\n const inputFile = inputFileDiv.text();\r\n const outputFileDiv = $(\"div.output-file\");\r\n const outputFile = outputFileDiv.text();\r\n\r\n\r\n if (!endsWith(inputFile, \"standard input\")\r\n && !endsWith(inputFile, \"standard input\")) {\r\n inputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n if (!endsWith(outputFile, \"standard output\")\r\n && !endsWith(outputFile, \"standard output\")) {\r\n outputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n const titleDiv = $(\"div.header div.title\");\r\n\r\n\r\n\r\n String.prototype.replaceAll = function (search, replace) {\r\n return this.split(search).join(replace);\r\n };\r\n\r\n $(\".sample-test .title\").each(function () {\r\n const preId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n const cpyId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n\r\n $(this).parent().find(\"pre\").attr(\"id\", preId);\r\n const $copy = $(\"<div title='Copy' data-clipboard-target='#\" + preId + \"' id='\" + cpyId + \"' class='input-output-copier'>Copy</div>\");\r\n $(this).append($copy);\r\n\r\n const clipboard = new Clipboard('#' + cpyId, {\r\n text: function (trigger) {\r\n const pre = document.querySelector('#' + preId);\r\n const lines = pre.querySelectorAll(\".test-example-line\");\r\n return Codeforces.filterClipboardText(pre.innerText, lines.length);\r\n }\r\n });\r\n\r\n const isInput = $(this).parent().hasClass(\"input\");\r\n\r\n clipboard.on('success', function (e) {\r\n if (isInput) {\r\n Codeforces.showMessage(\"The example input has been copied into the clipboard\");\r\n } else {\r\n Codeforces.showMessage(\"The example output has been copied into the clipboard\");\r\n }\r\n e.clearSelection();\r\n });\r\n });\r\n\r\n $(\".test-form-item input\").change(function () {\r\n addPendingSubmissionMessage($($(this).closest(\"form\")), \"You changed the answer, do not forget to submit it if you want to save the changes\");\r\n const index = $(this).closest(\".problemindexholder\").attr(\"problemindex\");\r\n let test = \"\";\r\n $(this).closest(\"form input\").each(function () {\r\n const test_ = $(this).attr(\"name\");\r\n if (test_ && test_.substring(0, 4) === \"test\") {\r\n test = test_;\r\n }\r\n });\r\n if (index.length > 0 && test.length > 0) {\r\n const indexTest = index + \"::\" + test;\r\n window.changedTests.add(indexTest);\r\n }\r\n });\r\n\r\n $(window).on('beforeunload', function () {\r\n if (window.changedTests.size > 0) {\r\n return 'Dialog text here';\r\n }\r\n });\r\n\r\n autosize($('.test-explanation textarea'));\r\n\r\n $(\".test-example-line\").hover(function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n let top = 1E20;\r\n let left = 1E20;\r\n let problem = $(this).closest(\".problemindexholder\");\r\n $(this).closest(\".input\").find(\".\" + clazz).css(\"background-color\", \"#FFFDE7\").each(function() {\r\n top = Math.min(top, $(this).offset().top);\r\n left = Math.min(left, $(this).offset().left);\r\n });\r\n let testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n if (testCaseMarker.length === 0) {\r\n const html = \"<div class=\\\"testCaseMarker testCaseMarker_\" + end + \" notice\\\"></div>\";\r\n problem.append($(html));\r\n testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n }\r\n if (testCaseMarker) {\r\n testCaseMarker.show()\r\n .offset({top, left: left - 20})\r\n .text(end);\r\n }\r\n }\r\n }\r\n });\r\n }, function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n $(\".\" + clazz).css(\"background-color\", \"\");\r\n $(this).closest(\".problemindexholder\").find(\".testCaseMarker_\" + end).hide();\r\n }\r\n }\r\n });\r\n });\r\n\r\n });\r\n</script>\r\n\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 05:38:38</span> (j3).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/73366/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/73366/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/73366/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/73366/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-73366.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'8122c4e5898e9d64',t:'MTY5NjY0NjMxOS4wMTMwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"},"long_tags":{"kind":"string","value":"[\"Binary search\", \"Dynamic programming\", \"Greedy algorithms\"]"},"short_tags":{"kind":"string","value":"[\"binary search\", \"dp\", \"greedy\", \"*1400\"]"},"tutorial_link":{"kind":"string","value":"https://codeforces.com/blog/entry/10629"},"tutorial_page":{"kind":"string","value":"\r\n\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"74361418aed3add319d25ce966ceafdf\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"h1\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Codeforces Round #228 — Editorial - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n \n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Codeforces Round #228 — Editorial - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/81027/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/81027/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/81027/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/81027/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/81027/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/81027/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/81027/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/81027/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/81027/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/81027/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/81027/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/81027/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/81027/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/81027/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/573cedc6b04c15481941f418269f4057/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='74361418aed3add319d25ce966ceafdf'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/81027/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fblog%2Fentry%2F10629\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='74361418aed3add319d25ce966ceafdf'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Pay attention\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n <div style=\"text-align:center;border-bottom: 1px solid rgb(185, 185, 185);margin:0 -0.5em 0.5em -0.5em;padding: 0 1em 0.5em 1em;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 1, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:51:54</span><br/><a href=\"/contestRegistration/1876\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n <div style=\"text-align:center;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 2, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:51:54</span><br/><a href=\"/contestRegistration/1877\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='74361418aed3add319d25ce966ceafdf'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n </label>\r\n </div>\r\n <div style=\"padding: 0 1em 1em 1em;text-align:right;\">\r\n <input style=\"height:1.65em;padding:0 0.75em;\" type=\"submit\" value=\"Find\"/>\r\n </div>\r\n </form>\r\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".handleBox\").autocomplete(\"/data/handles\", {\r\n delay: 200,\r\n width: 200,\r\n selectFirst: false,\r\n matchContains: true,\r\n minChars: 3\r\n });\r\n $(\".handleForm\").attr(\"autocomplete\", \"off\").submit(function () {\r\n var link = \"/profile/userHandle\".replace(\r\n \"userHandle\", $(this).find(\".handleBox\").val()\r\n );\r\n window.location = link;\r\n return false;\r\n });\r\n });\n </script>\n\r\n\r\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Recent actions\n <div class=\"top-links\">\n </div>\n </div>\n <div class=\"recent-actions\">\r\n <ul>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/121073\">Meta Hacker Cup 2023 Round 1</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/.Danet\" title=\"Expert .Danet\" class=\"rated-user user-blue\">.Danet</a> →\r\n <a href=\"/blog/entry/121172\">[TLE on pretest1]</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\" class=\"rated-user user-red\">Pyqe</a> →\r\n <a href=\"/blog/entry/121025\">Codeforces Round #902 (Div. 1, Div. 2, based on COMPFEST 15 — Final Round)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pranshu_Pandya\" title=\"Specialist Pranshu_Pandya\" class=\"rated-user user-cyan\">Pranshu_Pandya</a> →\r\n <a href=\"/blog/entry/121171\">An Interesting Tree Problem</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/sszcdjr\" title=\"Master sszcdjr\" class=\"rated-user user-orange\">sszcdjr</a> →\r\n <a href=\"/blog/entry/119859\">Codeforces Round 896 (Div. 1, Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/119880\">It's Happening! Meta Hacker Cup 2023 Schedule</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/DaviddeGea1\" title=\"Expert DaviddeGea1\" class=\"rated-user user-blue\">DaviddeGea1</a> →\r\n <a href=\"/blog/entry/70917\">Number of ways of dividing an array into 2 parts such that sum of each part is > k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bekh\" title=\"Master Bekh\" class=\"rated-user user-orange\">Bekh</a> →\r\n <a href=\"/blog/entry/74245\">Questions and doubts regarding Aliens DP trick</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a> →\r\n <a href=\"/blog/entry/8192\">Codeforces Round #190 — Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/hocky\" title=\"Candidate Master hocky\" class=\"rated-user user-violet\">hocky</a> →\r\n <a href=\"/blog/entry/95323\">FBHC wuining uw Day? Incwease uw stacc size! (ㅅ´ ˘ `)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/liouzhou_101\" title=\"International Master liouzhou_101\" class=\"rated-user user-orange\">liouzhou_101</a> →\r\n <a href=\"/blog/entry/87598\">Editorial of Codeforces Round #700</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/yeon_gist\" title=\"Newbie yeon_gist\" class=\"rated-user user-gray\">yeon_gist</a> →\r\n <a href=\"/blog/entry/121170\">plusMinusPermutation computing error</a>\r\n <img alt=\"Text created or updated\" title=\"Text created or updated\" src=\"//codeforces.org/s/81027/images/icons/x-update-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/altforminuscontribution\" title=\"Newbie altforminuscontribution\" class=\"rated-user user-gray\">altforminuscontribution</a> →\r\n <a href=\"/blog/entry/121162\">My screen get unexpectedly big, what should I do</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/atcoder_official\" title=\"Unrated, atcoder_official\" class=\"rated-user user-black\">atcoder_official</a> →\r\n <a href=\"/blog/entry/121120\">We will hold UNIQUE VISION Programming Contest 2023 Autumn(AtCoder Beginner Contest 323)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/YouStill_DontKnowMeYet\" title=\"Candidate Master YouStill_DontKnowMeYet\" class=\"rated-user user-violet\">YouStill_DontKnowMeYet</a> →\r\n <a href=\"/blog/entry/117659\">[GYM] Al-Baath Collegiate Programming Contest 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/ankancool\" title=\"Expert ankancool\" class=\"rated-user user-blue\">ankancool</a> →\r\n <a href=\"/blog/entry/121136\">Invitation to AstroByte 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/GeZhiyuan\" title=\"Grandmaster GeZhiyuan\" class=\"rated-user user-red\">GeZhiyuan</a> →\r\n <a href=\"/blog/entry/120943\">Codeforces Round 901 (Div. 1, Div. 2) Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a> →\r\n <a href=\"/blog/entry/120772\">PSA: Increase your stack size before the Meta Hacker Cup, here's how</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/dino_merlin\" title=\"Expert dino_merlin\" class=\"rated-user user-blue\">dino_merlin</a> →\r\n <a href=\"/blog/entry/121145\">Intuitive approach for CEOI Kangaroo?</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/icecuber\" title=\"Grandmaster icecuber\" class=\"rated-user user-red\">icecuber</a> →\r\n <a href=\"/blog/entry/70018\">CSES DP section editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bn00b\" title=\"Newbie Bn00b\" class=\"rated-user user-gray\">Bn00b</a> →\r\n <a href=\"/blog/entry/98820\">[FEATURE REQUEST : ATCODER] TOPICS TAGS AND SORTING BY SOLVE COUNT</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a> →\r\n <a href=\"/blog/entry/121163\">AtCoder Regular Contest 166 Announcement</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/windva\" title=\"Grandmaster windva\" class=\"rated-user user-red\">windva</a> →\r\n <a href=\"/blog/entry/120644\">Codeforces Round 899 (Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Misa-Misa\" title=\"Expert Misa-Misa\" class=\"rated-user user-blue\">Misa-Misa</a> →\r\n <a href=\"/blog/entry/121157\">Someone please help me understand this.</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/shivam565\" title=\"Specialist shivam565\" class=\"rated-user user-cyan\">shivam565</a> →\r\n <a href=\"/blog/entry/108348\">Total number of subarrays with sum atmost k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n </ul>\r\n </div>\r\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/recent-actions\">Detailed →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n</div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li><a\r\n href=\"/profile/cgy4ever\">cgy4ever</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/cgy4ever\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/cgy4ever\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/cgy4ever\">Submissions</a></li>\r\n <li><a\r\n href=\"/groups/with/cgy4ever\">Groups</a></li>\r\n <li><a\r\n href=\"/contests/with/cgy4ever\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/cgy4ever\">Problemsetting</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/cgy4ever\" style=\"text-decoration:none;color:black !important;\">cgy4ever's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"10684\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/10629\"> <p>Codeforces Round #228 — Editorial</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a>,\r\n <span class=\"format-humantime\" title=\"Feb/03/2014 22:14\">10 years ago</span>,\r\n \r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p>You can find the editorial and my solutions here: <a href=\"https://github.com/cgy4ever/CF228\">https://github.com/cgy4ever/CF228</a></p><p><a href=\"/contest/389/problem/A\" title=\"Codeforces Round 228 (Div. 2)\">389A - Fox and Number Game</a></p><p>First we know that: in the optimal solution, all number will be equal: otherwise we can pick a and b (a < b) then do b = b — a, it will make the answer better.</p><p>Then we need an observation: after each operation, the GCD (Greatest common divisor) of all number will remain same. It can be proved by this lemma: if g is a divisor of all number of x[], then after the operation, g is still the divisor of these numbers, and vice versa.</p><p>So in the end, all number will become the GCD of x[].</p><p>Another solution that can pass is: While there exist x[i] > x[j], then do x[i] -= x[j]. We can select arbitrary i and j if there exist more than 1 choice.</p><p><a href=\"/contest/389/problem/B\" title=\"Codeforces Round 228 (Div. 2)\">389B - Fox and Cross</a></p><p>Let's define the first # of a shape is the cell contain # that have the lexicographical smallest coordinate. Then the first # of a cross is the top one.</p><p>Then let x be the first # of the given board. (If the board is empty, then we can draw it with zero crosses.) x must be covered by a cross, and x must be the first # of the cross. (You can try 4 other positions, it will cause a lexicographical smaller # in the board than x)</p><p>So we try to cover this x use one cross, if it leads some part of the cross covers a '.', then there will be no solution. If not, we just reduce the number of # in the board by 4, we can do this again and again.</p><p><a href=\"/contest/389/problem/C\" title=\"Codeforces Round 228 (Div. 2)\">389C - Fox and Box Accumulation</a> / <a href=\"/contest/388/problem/A\" title=\"Codeforces Round 228 (Div. 1)\">388A - Fox and Box Accumulation</a></p><p>We need some observation:</p> <ol> <li><p>There exists an optimal solution such that: in any pile, the box on the higher position will have a smaller strength.</p></li> <li><p>Let k be the minimal number of piles, then there exists an optimal solution such that: The height of all piles is n/k or n/k+1 (if n%k=0, then all of them have the height n/k).</p></li> </ol><p>We can prove them by exchange argument: from an optimal solution, swap the boxes in it to make above property holds, and we can ensure it will remain valid while swapping.</p><p>Then for a given k, we can check whether there exist a solution: the i-th (indexed from 0) smallest strength needs to be at least i/k.</p><p>So we can do binary search (or just enumerate, since n is only 100) on k.</p><p><a href=\"/contest/389/problem/D\" title=\"Codeforces Round 228 (Div. 2)\">389D - Fox and Minimal path</a> / <a href=\"/contest/388/problem/B\" title=\"Codeforces Round 228 (Div. 1)\">388B - Fox and Minimal path</a></p><p>First we need to know how to calculate the number of different shortest paths from vertex 1 to vertex 2: it can be done by dp: dp[1] = 1, dp[v] = sum{dp[t] | dist(1,t) = dist(1,v) — 1}, then dp[2] is our answer.</p><p>We need to do dp layer by layer. (first we consider vertexes have distance 1 to node 1, then vertexes have distance 2 to node 1 and so on.) So we can construct the graph layer by layer, and link edges to control the dp value of it.</p><p>My solution is construct the answer by binary express: If k is 19, then we need some vertexes in previous layer such that the dp value is 16, 2 and 1. So we just need a way to construct layer with dp value equals to 2^k.</p><p>In the first layer, it contains one node: 1, it has the dp value 1. In the next layer, we can construct 2 nodes, with dp value equals to 1. (We use [1 1] to denote it). And the next layer is [1 1 2], then [1 1 2 4], [1 1 2 4 8] and so on. So we need about 30 layers such that gets all 2^k where k < 30. It uses about 500 nodes.</p><p><a href=\"/contest/389/problem/E\" title=\"Codeforces Round 228 (Div. 2)\">389E - Fox and Card Game</a> / <a href=\"/contest/388/problem/C\" title=\"Codeforces Round 228 (Div. 1)\">388C - Fox and Card Game</a></p><p>First let's consider the case which all piles have even size. In this case, we can prove: in the optimal play, Ciel will gets all top most half cards of each pile, and Jiro gets the remain cards.</p><p>We can prove by these facts: Ciel have a strategy to ensure she can get this outcome and Jiro also have a strategy to ensure this outcome. (For Jiro this strategy is easy: just pick the card from pile that Ciel have just picked. For Ciel it's a little bit harder.)</p><p>Why we can conclude they are both the optimal strategy? Ciel just can't win more, because if she played with Jiro with above strategy, Jiro will get the bottom half of each pile.</p><p>Then we come back with cases that contain odd size piles. The result is: for odd size pile, Ciel will get the top (s-1)/2 cards and Jiro will get the bottom (s-1)/2 cards. Then what about the middle one? Let's denote S is all such middle cards. Then we define a reduced game: In each turn, they pick one card from S. The optimal play for this game is easy: Ciel gets the max one, and Jiro gets the 2nd largest one, and Ciel gets the 3rd largest one and so on.</p><p>We can prove Ciel have a strategy to get: all top half parts + cards she will get in the optimal play in the reduced game. And Jiro also have a strategy to get: all bottom half parts + cards he will get in the optimal play in the reduced game. And these strategy are optimal.</p><p><a href=\"/contest/388/problem/D\" title=\"Codeforces Round 228 (Div. 1)\">388D - Fox and Perfect Sets</a></p><p>A perfect set correspond to a linear space, so we can use base to represent it. We do the Gauss–Jordan elimination of vectors in that set, and can get an unique base. (Note that we need to to the all process of Gauss–Jordan elimination, including the elimination after it reached upper triangular)</p><p>And we can construct the bases bit by bit from higher bit to lower, for a bit:</p> <ol> <li><p>We can add a vector to the base such that the bit is the highest bit of that vector. And at this time, all other vector will have 0 in this bit.</p></li> <li><p>Otherwise we need to assign this bit of each vector already in the base. If now we have k vector, then we have 2^k choices.</p></li> </ol><p>And when we do this, we need to know what's the maximal vector in this space. It's not hard:</p> <ol> <li><p>If we add a vector, then in the maximal vector, this bit will be 1.</p></li> <li><p>Otherwise, if we don't have any vector in base yet, then this bit will be 0. Otherwise there will be 2^(k-1) choices results in this bit of maximal vector will be 0, and 2^(k-1) choices results in 1.</p></li> </ol><p>So we can solve this task by DP bit by bit.</p><p><a href=\"/contest/388/problem/E\" title=\"Codeforces Round 228 (Div. 1)\">388E - Fox and Meteor Shower</a></p><p>All tasks beside this are very easy to code. And this one focus on implementation.</p><p>We can represent the orbit of each meteor by a line in 3D space. (we use an axis to represent the time, and two axis to represent the position on the plane.)</p><p>Then the problem becomes: we have some lines in 3D space (they are not complete coincide), find a largest clique such that each pair of lines touch at some point.</p><p>We need this observation: If there are 3 lines in the optimal clique, and these 3 lines are not share a common point, then all line in this clique will on a plane.</p><p>By using this observation, we only need to consider 2 cases:</p> <ol> <li><p>All lines in the clique have a common point.</p></li> <li><p>All lines in the clique are on the same plane.</p></li> </ol><p>Both are easy tasks in theory, but it needs some coding.</p><p>There are two ways:</p> <ol> <li><p>Use integer anywhere. Note that the coordinates of intersection can be rational number, but can't be irrational, so we could do this. We can use some way to encode the plane, direction.</p></li> <li><p>Use floating number. To count same number of points, we can sort (x, y, z) by using the following compare function: if (abs(A.x — B.x) > eps){return A.x < B.x} otherwise { if(abs(A.y-B.y)>eps){return A.y < B.y} otherwise return A.z < B.z}.</p></li> </ol></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/388\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 228 (Div. 1)</a> </span>\r\n </div>\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/389\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 228 (Div. 2)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-21-10684\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"21\",\n blogEntryId: \"10629\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-10684\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+45</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-10684\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/cgy4ever\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/cgy4ever\">\n cgy4ever\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Feb/03/2014 22:14\">10 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/10629#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/10629#comments\">\n 44\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"10700\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (39)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159842\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/YaleZ\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/24526/avatar/5b17db1affad55a5.jpg'/> </a>\n <div><a href=\"/profile/YaleZ\" title=\"Expert YaleZ\" class=\"rated-user user-blue\">YaleZ</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2014 22:38\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159842\" href=\"?#comment-159842\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"159842\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"159842\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"24526\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159842\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thank for timely editorial. I think Markdown is better when publish something on Github. Isn't it?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159842 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159842 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159842\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159846\" commentParentId=\"159842\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/cgy4ever\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2014 22:43\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159846\" href=\"?#comment-159846\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159842\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159846\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"11\"\r\n data-commentUserId=\"62\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+11</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159846\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Yes, I'm working on it. :)</p><p>The website seems to be not stable at this time. So I post them in other sites to ensure all people can see it.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159846 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159846 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159846\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159857\" commentParentId=\"159846\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Nodir.Daminov\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/71439/avatar/d6d2016f6dfe5ecd.jpg'/> </a>\n <div><a href=\"/profile/Nodir.Daminov\" title=\"Candidate Master Nodir.Daminov\" class=\"rated-user user-violet\">Nodir.Daminov</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2014 22:58\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159857\" href=\"?#comment-159857\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159846\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159857\" class=\"CommentVoteFrame\"\r\n class=\"too-negative-comment-vote\"\r\n data-commentRating=\"-35\"\r\n data-commentUserId=\"71439\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-35</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159857\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Maaan is it so hard to COPY ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159857 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159857 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159857\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159874\" commentParentId=\"159857\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/cgy4ever\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2014 23:19\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159874\" href=\"?#comment-159874\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159857\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159874\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"12\"\r\n data-commentUserId=\"62\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+12</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159874\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Sorry for the delay.</p><p>When I was submitting my post that contains the editorial, it always returns "Codeforces is now unavailable." so I just can't post it.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159874 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159874 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159874\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159859\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/BishalG\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/60637/avatar/d21ddf49bbd1630c.jpg'/> </a>\n <div><a href=\"/profile/BishalG\" title=\"Expert BishalG\" class=\"rated-user user-blue\">BishalG</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2014 22:58\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159859\" href=\"?#comment-159859\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159859\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"60637\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159859\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Nice problemSets @<a class=\"rated-user user-orange\" href=\"/profile/cgy4ever\" title=\"International Master cgy4ever\">cgy4ever</a> , although I misunderstood the problem-B <a href=\"/contest/389/problem/B\" title=\"Codeforces Round 228 (Div. 2)\">389B - Fox and Cross</a> upto 1 hrs :( </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159859 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159859 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159859\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159867\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Mr.ink\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Mr.ink\" title=\"Expert Mr.ink\" class=\"rated-user user-blue\">Mr.ink</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2014 23:07\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159867\" href=\"?#comment-159867\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159867\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"128876\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159867\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>due to my slow internet speed i can not see your editorial on github because my country internet has problem with https! </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159867 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159867 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159867\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159881\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Mr.ink\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Mr.ink\" title=\"Expert Mr.ink\" class=\"rated-user user-blue\">Mr.ink</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2014 23:38\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159881\" href=\"?#comment-159881\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159881\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"128876\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159881\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>does anyone have a better solution for div2 C problem?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159881 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159881 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159881\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159883\" commentParentId=\"159881\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/t_thirupathi\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/146179/avatar/98c28348196ce4ca.jpg'/> </a>\n <div><a href=\"/profile/t_thirupathi\" title=\"Specialist t_thirupathi\" class=\"rated-user user-cyan\">t_thirupathi</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2014 23:42\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159883\" href=\"?#comment-159883\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159881\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159883\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"146179\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159883\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Have a look at mine <a href=\"/contest/389/submission/5878414\" title=\"Submission 5878414 by t_thirupathi\">5878414</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159883 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159883 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159883\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159909\" commentParentId=\"159883\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/9charles\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/119814/avatar/653156a3153bc2dd.jpg'/> </a>\n <div><a href=\"/profile/9charles\" title=\"Expert 9charles\" class=\"rated-user user-blue\">9charles</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 06:46\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159909\" href=\"?#comment-159909\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159883\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159909\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"119814\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159909\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can you explain it?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159909 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159909 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159909\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159907\" commentParentId=\"159881\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/k790alex\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/119882/avatar/4baeddca65b2b958.jpg'/> </a>\n <div><a href=\"/profile/k790alex\" title=\"Specialist k790alex\" class=\"rated-user user-cyan\">k790alex</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 06:28\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159907\" href=\"?#comment-159907\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159881\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159907\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"119882\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159907\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I don't know if this is a better way but I didt in the contest.</p><p>Start making a pile with the low strength and while possible, look for a box that can support at least 1 box, then at least 2 boxes, 3, etc, repeat it while you have boxes.</p><p>My solution: <a href=\"/contest/389/submission/5879464\" title=\"Submission 5879464 by k790alex\">5879464</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159907 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159907 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159907\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159914\" commentParentId=\"159907\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/YaleZ\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/24526/avatar/5b17db1affad55a5.jpg'/> </a>\n <div><a href=\"/profile/YaleZ\" title=\"Expert YaleZ\" class=\"rated-user user-blue\">YaleZ</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 07:38\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159914\" href=\"?#comment-159914\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159907\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159914\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"24526\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159914\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Greedy is also a nice solution.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159914 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159914 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159914\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159932\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/worfzyq\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/157364/avatar/8f104a361ed91be8.jpg'/> </a>\n <div><a href=\"/profile/worfzyq\" title=\"Expert worfzyq\" class=\"rated-user user-blue\">worfzyq</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 09:52\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159932\" href=\"?#comment-159932\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159932\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"157364\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159932\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>388C — Fox and Card Game This problem is good magic</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159932 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159932 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159932\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159935\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/orchidmajumder\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/63603/avatar/f8db3747466a7168.jpg'/> </a>\n <div><a href=\"/profile/orchidmajumder\" title=\"Specialist orchidmajumder\" class=\"rated-user user-cyan\">orchidmajumder</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 10:07\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159935\" href=\"?#comment-159935\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"159935\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"159935\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"7\"\r\n data-commentUserId=\"63603\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+7</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159935\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>hii everyone,in Div II E,I can't understand why the optimal play for JIRO is to take the bottom most card from the same pile from where CIEL is picking?should not it try to pick the maximum value among all bottom most card at it's every move??</p><p>Please someone explain why the strategy presented in the editorial is optimal.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159935 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159935 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159935\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159948\" commentParentId=\"159935\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Zzyzx\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/86049/avatar/c698ee674460e7eb.jpg'/> </a>\n <div><a href=\"/profile/Zzyzx\" title=\"Expert Zzyzx\" class=\"rated-user user-blue\">Zzyzx</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 13:07\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159948\" href=\"?#comment-159948\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159935\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159948\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"86049\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159948\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Ok, I'm afraid I do not have a rigorous proof for this. I'll just explain to you why I think it is right.</p><p>First of all, we need to understand that both Ciel and Jiro are smart. Now, whenever it is Ciel's turn, he will pick the "best pile" and try to take everything from that pile and then move on to the next "best pile". Jiro knows that his friend Ciel is smart, so he will try to stop him from taking everything. This can be done only if he picks from the same pile that Ciel does.</p><p>But your question is — what if there is a different pile whose bottom-most card is much better than the bottom-most card of the pile from which Ciel is picking right?</p><p>My answer to this is that, this situation will never arise. Because if there is such a pile, then Ciel will try to take that card in the first place and therefore, Ciel will be picking from the same pile that Jiro will want to pick from.</p><p>Am I making sense? Or is there a flaw in my argument?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159948 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159948 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159948\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159952\" commentParentId=\"159948\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/orchidmajumder\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/63603/avatar/f8db3747466a7168.jpg'/> </a>\n <div><a href=\"/profile/orchidmajumder\" title=\"Specialist orchidmajumder\" class=\"rated-user user-cyan\">orchidmajumder</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 13:32\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159952\" href=\"?#comment-159952\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159948\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159952\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"63603\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159952\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Yes I'm also thinking along the same line.Both are playing optimally and if Ciel is chosing any pile then jiro knows that this pile has better cards in the botttom half.So he won't choose ciel to take the advantage and vice versa.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159952 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159952 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159952\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159944\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hzyfr\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/hzyfr\" title=\"Expert hzyfr\" class=\"rated-user user-blue\">hzyfr</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 12:27\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159944\" href=\"?#comment-159944\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159944\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"129936\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159944\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I have a different idea on D div1 <a href=\"/contest/388/problem/D\" title=\"Codeforces Round 228 (Div. 1)\">388D - Fox and Perfect Sets</a> but I failed on getting some relations in one step.</p><p>Let <em>M</em> be the maximum element in set <em>S</em> . Then if <em>S</em> is a perfect set, its elements should have all bits equals <em>0</em> on positions in <em>M's</em> binary representation(otherwise there must exist another element bigger than <em>M</em>). So let <em>cnt</em> = (number of 1's in binary repersentation of <em>M</em>), then the number of perfect sets which has <em>M</em> as its greatest element is determined by <em>cnt</em> . Well, this is the step I can't come up with a solution(actually the target is to find the number of perfect sets which has <code>2^cnt-1</code> as its greatest element).</p><p>Then the last step is simple. We can apply something like doubling algorithm on the problem.</p><p>We are asked to find the number of perfect sets with all the elements not greater than <em>N</em> . Let's suppose <em>N+1</em> is a power of 2 then its easy to calculate how many numbers not greater than <em>N</em> has <em>cnt</em> = 1,2,...m where m is the length of <em>N</em> in binary representation. That's just simple combinatoric number <em>C(n,i) (1<=i<=n)</em> . And if we have done the previous step, it's easy to get the result.</p><p>Then think about common cases of <em>N</em> . Let's take the highest bit of N and since all above bits are determined, the number of 1's will just add a constant value. So calculate this part and subtract that highest bit of <em>N</em> and do the same thing on remaining value of <em>N</em> , until <em>N=0</em> . At that time we will get the correct answer. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159944 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159944 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159944\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159945\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/rexdf\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/23738/avatar/797fa665fbe1ca78.jpg'/> </a>\n <div><a href=\"/profile/rexdf\" title=\"Specialist rexdf\" class=\"rated-user user-cyan\">rexdf</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 12:36\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159945\" href=\"?#comment-159945\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159945\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"23738\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159945\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>dp[1] = 1, dp[v] = sum{dp[t] | dist(1,t) = dist(1,v) — 1}, then dp[2] is our answer. What's v means? what's '|' means? What's dp[v] means?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159945 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159945 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159945\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159949\" commentParentId=\"159945\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/sancho\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/85894/avatar/e31a4b24327c1000.jpg'/> </a>\n <div><a href=\"/profile/sancho\" title=\"Candidate Master sancho\" class=\"rated-user user-violet\">sancho</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 13:10\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159949\" href=\"?#comment-159949\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159945\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159949\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"85894\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159949\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>v — vertex, answer for which we are getting at this moment, | — means "such as", dp[v] — number of ways from 1 vertex to this one</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159949 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159949 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159949\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159947\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lol12\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/lol12\" title=\"Specialist lol12\" class=\"rated-user user-cyan\">lol12</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 13:04\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159947\" href=\"?#comment-159947\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159947\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"10\"\r\n data-commentUserId=\"152356\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+10</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159947\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can someone please explain solution of Div2-D. Thanx</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159947 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159947 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159947\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"160020\" commentParentId=\"159947\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/YaleZ\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/24526/avatar/5b17db1affad55a5.jpg'/> </a>\n <div><a href=\"/profile/YaleZ\" title=\"Expert YaleZ\" class=\"rated-user user-blue\">YaleZ</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/05/2014 07:07\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-160020\" href=\"?#comment-160020\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159947\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"160020\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"9\"\r\n data-commentUserId=\"24526\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+9</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-160020\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>You can think about binnary. Such as (13)10=(1101)2=((1+(2+0)*2)+1)*2+1</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-160020 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-160020 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-160020\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"469976\" commentParentId=\"159947\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/roll_no_1\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/631859/avatar/36d157f91f64fe7f.jpg'/> </a>\n <div><a href=\"/profile/roll_no_1\" title=\"Master roll_no_1\" class=\"rated-user user-orange\">roll_no_1</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Nov/09/2018 17:27\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-469976\" href=\"?#comment-469976\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159947\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"469976\" revisionCount=\"4\" revision=\"4\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">4</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"469976\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"631859\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-469976\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Here's my implementation of the editorialist's explanation of Div-2 D / Div-1 B: <a href=\"/contest/388/submission/45480077\" title=\"Submission 45480077 by roll_no_1\">45480077</a>. I implemented the layers as [1], [1, 1], [2, 1, 1], [4, 2, 1, 1] and so on.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-469976 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-469976 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-469976\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159967\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/BENYAM1N\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/84938/avatar/d2ae2657d8898e38.jpg'/> </a>\n <div><a href=\"/profile/BENYAM1N\" title=\"Master BENYAM1N\" class=\"rated-user user-orange\">BENYAM1N</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 15:51\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159967\" href=\"?#comment-159967\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159967\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"13\"\r\n data-commentUserId=\"84938\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+13</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159967\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Very good contest and nice editorial. Hope from now on I see more contests from you.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159967 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159967 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159967\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159984\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/kojak_\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/57722/avatar/38990eea59bc188e.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/kojak_\" title=\"Newbie kojak_\" class=\"rated-user user-gray\">kojak_</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 18:34\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159984\" href=\"?#comment-159984\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159984\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"57722\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159984\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Did anyone come up with a DP solution for Div.2 C/ Div.1 A?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159984 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159984 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159984\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"160012\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/IgorKoval\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/51322/avatar/afc854fff49f072a.jpg'/> </a>\n <div><a href=\"/profile/IgorKoval\" title=\"Candidate Master IgorKoval\" class=\"rated-user user-violet\">IgorKoval</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 23:17\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-160012\" href=\"?#comment-160012\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"160012\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"11\"\r\n data-commentUserId=\"51322\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+11</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-160012\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Объясните, пожалуйста, разбор задачи "388D — Fox and Perfect Sets" на пальцах. Как-нибудь без Гаусса и базисов. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-160012 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-160012 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-160012\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"160016\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Mr.ink\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Mr.ink\" title=\"Expert Mr.ink\" class=\"rated-user user-blue\">Mr.ink</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/05/2014 01:08\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-160016\" href=\"?#comment-160016\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"160016\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"128876\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-160016\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>fox and card games is a great problem.thanks!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-160016 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-160016 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-160016\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"160037\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/yaswanth\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/yaswanth\" title=\"Specialist yaswanth\" class=\"rated-user user-cyan\">yaswanth</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/05/2014 18:38\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-160037\" href=\"?#comment-160037\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"160037\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"9\"\r\n data-commentUserId=\"96196\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+9</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-160037\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can anyone explain div2 C question? I did not understand the editorial.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-160037 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-160037 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-160037\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"160063\" commentParentId=\"160037\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/YaleZ\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/24526/avatar/5b17db1affad55a5.jpg'/> </a>\n <div><a href=\"/profile/YaleZ\" title=\"Expert YaleZ\" class=\"rated-user user-blue\">YaleZ</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/06/2014 05:46\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-160063\" href=\"?#comment-160063\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-160037\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"160063\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"24526\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-160063\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>s[i]>=i/k -> k*s[i]>=i There are i boxes' strength smaller than i-th box. So we need to check if the boxes before i-th can be held.</p><p>(I don't know whether I have understood correctly...)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-160063 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-160063 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-160063\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"160053\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/yada\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/142663/avatar/49901b54d1c5f019.jpg'/> </a>\n <div><a href=\"/profile/yada\" title=\"Candidate Master yada\" class=\"rated-user user-violet\">yada</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/05/2014 23:24\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-160053\" href=\"?#comment-160053\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"160053\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"142663\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-160053\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Great Problem! I really enjoy it.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-160053 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-160053 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-160053\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"364019\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lnzva\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/305672/avatar/cf6c09a214141751.jpg'/> </a>\n <div><a href=\"/profile/lnzva\" title=\"Expert lnzva\" class=\"rated-user user-blue\">lnzva</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/02/2017 22:06\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-364019\" href=\"?#comment-364019\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"364019\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"364019\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"305672\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-364019\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In 388C, I'm having a hard time understanding why Jiro's optimal strategy would be to pick the pile Ciel just picked. Why not pick a pile which has a better bottom part than the one Ciel is picking? According to some comments, Ciel would then pick from the second pile-what if another pile has a much better top part? Could someone please help? I saw this problem first 6 months ago, and I had a hard time understanding why this greedy is correct; I saw this problem again today and am having trouble with it again, with no progress.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-364019 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-364019 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-364019\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"647866\" commentParentId=\"364019\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/_wzx27\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1458283/avatar/7d77b62012ae2398.jpg'/> </a>\n <div><a href=\"/profile/_wzx27\" title=\"Candidate Master _wzx27\" class=\"rated-user user-violet\">_wzx27</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/22/2020 18:33\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-647866\" href=\"?#comment-647866\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-364019\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"647866\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1458283\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-647866\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Let's consider such a two-piles situation:</p><p><em>111100</em></p><p><em>001111</em></p><p>is better for Ciel.</p><p>"1" means this card is picked by Ciel,while "0" by Jiro.</p><p>We know that better for Ciel means worse for Jiro.</p><p>So if</p><p><em>111100</em></p><p><em>001111</em></p><p>is better than</p><p><em>111000</em></p><p><em>000111</em></p><p>for Ciel.</p><p>Then when Ciel picked the <strong>first three cards</strong> from <strong>pile 1</strong>,Jiro can just pick the <strong>last three cards</strong> from <strong>pile 1</strong> and finally lead to the result:</p><p><em>111000</em></p><p><em>000111</em></p><p>which is not better for Ciel.</p><p>Generally, if the final result is not balance(half from top and half from bottom) while balance is better than such result for Jiro, Jiro has the ability to adjust it to be balance.So do Ciel.</p><p>Therefore,it reaches balance.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-647866 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-647866 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-647866\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"407776\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/madhur4127\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/568692/avatar/c7d62cc23c758819.jpg'/> </a>\n <div><a href=\"/profile/madhur4127\" title=\"Specialist madhur4127\" class=\"rated-user user-cyan\">madhur4127</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/15/2018 13:06\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-407776\" href=\"?#comment-407776\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"407776\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"568692\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-407776\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>@<a class=\"rated-user user-red\" href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\">cgy4ever</a>, github link shows 404 error(Page not found). Kindly fix it.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-407776 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-407776 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-407776\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"416354\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/introverted\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/657339/avatar/7a6edb1ecc1d3e09.jpg'/> </a>\n <div><a href=\"/profile/introverted\" title=\"Expert introverted\" class=\"rated-user user-blue\">introverted</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/23/2018 11:48\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-416354\" href=\"?#comment-416354\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"416354\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"657339\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-416354\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I solved the DIV1B problem with simple recursion and Divide and Conquer.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-416354 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-416354 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-416354\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"427890\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Nuu\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/652228/avatar/d59867d6477379dc.jpg'/> </a>\n <div><a href=\"/profile/Nuu\" title=\"Candidate Master Nuu\" class=\"rated-user user-violet\">Nuu</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/01/2018 22:33\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-427890\" href=\"?#comment-427890\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"427890\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"652228\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-427890\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can anyone give me some examples of the similar problems to DivC?? I think this problem is very nice for train brain xD</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-427890 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-427890 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-427890\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"629609\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/The_Alchemist\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1275181/avatar/662970aa05d3dfc5.jpg'/> </a>\n <div><a href=\"/profile/The_Alchemist\" title=\"Expert The_Alchemist\" class=\"rated-user user-blue\">The_Alchemist</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/25/2020 21:47\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-629609\" href=\"?#comment-629609\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"629609\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1275181\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-629609\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I know I am very late but can someone pls explain to me div 2C/div1A. Thanks in advance... </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-629609 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-629609 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-629609\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"641010\" commentParentId=\"629609\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/kstheking\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1160931/avatar/e144fc7b0fdb90b1.jpg'/> </a>\n <div><a href=\"/profile/kstheking\" title=\"Pupil kstheking\" class=\"rated-user user-green\">kstheking</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/13/2020 14:47\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-641010\" href=\"?#comment-641010\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-629609\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"641010\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1160931\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-641010\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p><a href=\"https://codeforces.com/contest/388/submission/83605110\">https://codeforces.com/contest/388/submission/83605110</a> Here you go, if you don't get it feel free to ask</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-641010 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-641010 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-641010\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"644488\" commentParentId=\"641010\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/tanisha_\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/tanisha_\" title=\"Newbie tanisha_\" class=\"rated-user user-gray\">tanisha_</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/18/2020 15:26\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-644488\" href=\"?#comment-644488\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-641010\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"644488\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1500127\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-644488\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>is this any algorithm</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-644488 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-644488 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-644488\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"647627\" commentParentId=\"644488\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/kstheking\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1160931/avatar/e144fc7b0fdb90b1.jpg'/> </a>\n <div><a href=\"/profile/kstheking\" title=\"Pupil kstheking\" class=\"rated-user user-green\">kstheking</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/22/2020 08:40\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-647627\" href=\"?#comment-647627\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-644488\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"647627\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"647627\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1160931\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-647627\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Well you can call it a greedy algorithm, when we try to apply greedy by placing the heaviest block in bottom, a little problem occurs because of blocks of same strength for example in case of 10 2 2 1 1 0 0<br />If you try to apply greedy by choosing the strongest block<br />10 2 2 1<br />1 0<br />0<br />= 3 heaps<br />Which is wrong answer as sometimes we lose opportunity to create lesser heaps, as in this case if we use the second 2 to make another heap we can do better<br />10 2 1 0<br />2 1 0<br />= 2 heaps<br />So I apply greedy in the reverse direction by picking the smallest strength brick and placing below it the next smallest brick, this way the optimal number of heaps will be formed as in above example<br />choose 0, then you need >= 1, choose 1, then you need >= 2, choose 2, then you need >= 3 choose 10<br />repeat until you have chosen all the bricks<br />If you don't get anything, feel free to ask :) </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-647627 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-647627 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-647627\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"702677\" commentParentId=\"647627\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/breddreamer\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/853067/avatar/240684624b57996.jpg'/> </a>\n <div><a href=\"/profile/breddreamer\" title=\"Newbie breddreamer\" class=\"rated-user user-gray\">breddreamer</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/27/2020 13:01\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-702677\" href=\"?#comment-702677\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-647627\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"702677\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"853067\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-702677\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks, It helped me to understand your solution idea. And finally, I solved this one.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-702677 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-702677 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-702677\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"649225\" commentParentId=\"641010\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/The_Alchemist\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1275181/avatar/662970aa05d3dfc5.jpg'/> </a>\n <div><a href=\"/profile/The_Alchemist\" title=\"Expert The_Alchemist\" class=\"rated-user user-blue\">The_Alchemist</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/24/2020 12:04\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-649225\" href=\"?#comment-649225\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-641010\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"649225\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1275181\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-649225\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>thank you.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-649225 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-649225 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-649225\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n <br/>\r\n\r\n<div id=\"editBox-10700\" style=\"width:50em;display:none;\">\r\n <div class=\"previewBody\" style=\"border: 1px solid #d4d4d4; margin-bottom: 0.5em; padding: 0.25em; display:none;\"> </div>\r\n <div style=\"width: 1px\"> </div>\r\n <div class=\"commentLocale\" style=\"position: relative; top: 0.5em;left:4px;display: none;\">\r\n <input type=\"radio\" name=\"locale\" value=\"en\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In English</span>\r\n <input style=\"margin-left:1em\" type=\"radio\" name=\"locale\" value=\"ru\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In Russian</span>\r\n </div>\r\n <textarea data-drafts-id=\"CommentReplyFrame\" class=\"wysiwyg\" name=\"editContent\" rows=\"20\" style=\"width:99%;\"></textarea>\r\n <div class=\"error error__content\"></div>\r\n <div style=\"text-align:center;\">\r\n <input type=\"button\" name=\"preview\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Preview\"/>\r\n <input type=\"button\" name=\"save\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Save\"/>\r\n </div>\r\n</div>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n\r\nvar firstPreview10700 = true;\r\nvar lastPreviewContent10700 = '';\r\n\r\nif (!window.moveCommentRevision) {\r\n moveCommentRevision = function(e, dir) {\r\n var p = e.parent();\r\n var revisionCount = parseInt(p.attr(\"revisionCount\"));\r\n var revision = parseInt(p.attr(\"revision\"));\r\n var next = revision + dir;\r\n var commentId = p.attr(\"commentId\");\r\n if (next >= 1 && next <= revisionCount) {\r\n $.post(\r\n \"/data/comment-data\",\r\n {action: \"revision\", commentId: commentId, revision: next},\r\n function(json) {\r\n if (json.success == \"true\") {\r\n var parentDiv = e;\r\n\r\n while (parentDiv !== null && (parentDiv[0].nodeName.toLowerCase() !== \"td\" || !parentDiv.hasClass(\"right\"))) {\r\n parentDiv = parentDiv.parent();\r\n }\r\n\r\n if (parentDiv === null) {\r\n return;\r\n }\r\n\r\n parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\").html(json.content);\r\n Codeforces.setupSpoilers(parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\"));\r\n p.attr(\"revision\", next);\r\n p.find(\"span.revision\").text(next);\r\n if (next == 1) {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"visible\");\r\n }\r\n if (next == revisionCount) {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"visible\");\r\n }\r\n\r\n window.updateTypography();\r\n MathJax.Hub.Typeset();\r\n } else {\r\n alert(e.error);\r\n }\r\n },\r\n \"json\"\r\n );\r\n }\r\n };\r\n}\r\n\r\n$(\"div[commentableId=10700] a.leftRevision\").click(function () {\r\n window.moveCommentRevision($(this), -1);\r\n return false;\r\n});\r\n\r\n$(\"div[commentableId=10700] a.rightRevision\").click(function () {\r\n window.moveCommentRevision($(this), +1);\r\n return false;\r\n});\r\n\r\n\r\n\r\n });\n </script>\n\r\n\r\n <script src=\"//codeforces.org/s/81027/js/swfobject-2.2.min.js\" type=\"text/javascript\"></script>\n <script src=\"//codeforces.org/s/81027/js/ftaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n if (window.evercookie) {\n var ec = new evercookie({\n history: false,\n silverlight: false,\n baseurl: '',\n asseturi: '/assets',\n phpuri: '/2fdcd78',\n pngPath: '/eps',\n etagPath: '/ees',\n cachePath: '/ecs'\n });\n\n var randomNumber = function () {\n return Math.random().toString(36).substr(2);\n };\n\n var randomToken = function () {\n return (randomNumber() + randomNumber()).substring(0, 18);\n };\n\n window._ftaa = \"\";\n\n ec.get(\"70a7c28f3de\", function (value) {\n window._ftaa = value;\n if (!window._ftaa) {\n window._ftaa = randomToken();\n ec.set(\"70a7c28f3de\", window._ftaa);\n }\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n } else {\n window._ftaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\n <script src=\"//codeforces.org/s/81027/js/bfaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n var fpCallback = function() {\n Fingerprint2.get({}, function(components) {\n window._bfaa = Fingerprint2.x64hash128(components.map(function (pair) { return pair.value }).join(), 31);\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n };\n if (typeof Fingerprint2 !== 'undefined') {\n if (window.requestIdleCallback) {\n requestIdleCallback(fpCallback)\n } else {\n setTimeout(fpCallback, 500)\n }\n } else {\n window._bfaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"a.new-root-comment\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n\r\n $(\".comment-table .reply a\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".vote-for-comment\").mouseover(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").mouseout(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").click(function () {\r\n var vote = $(this);\r\n var commentId = $(this).parent().attr(\"commentid\");\r\n var commentRating = $(this).parent().attr(\"data-commentRating\");\r\n var direction = $(this).attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n $.post(\"/data/comment/vote\", {commentId: commentId, _tta: Codeforces.tta(), vote: direction, commentRating: commentRating}, function(data) {\r\n if (direction != 0 && !ownComment && data[\"success\"] == \"true\") {\r\n vote.parent().find(\".vote-for-comment\").attr(\"voteDirection\", 0);\r\n if (direction == 1)\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n else {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.closest(\".CommentVoteFrame\").find(\".ComplaintFrame\").css(\"display\", \"inline-block\");\r\n }\r\n vote.find(\"img\").attr(\"popacity\", \"1.0\");\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n vote.parent().find(\".commentRating\").html(data[\"commentRating\"]);\r\n }\r\n Codeforces.showMessage(data[\"message\"]);\r\n }, \"json\");\r\n return false;\r\n });\r\n\r\n $(\".negative-comment-vote\").closest(\".comment-table\").addClass(\"comment-bad\");\r\n\r\n $(\".troll-comment-vote\").closest(\".comment\").css(\"display\", \"none\");\r\n\r\n $(\".too-negative-comment-vote\").closest(\".comment-table\").each(function () {\r\n var e = $(this);\r\n e.addClass(\"comment-too-bad\");\r\n var commentId = e.attr(\"commentId\");\r\n $(\"<div class='bad-comment-replacement ttypography'>The comment is hidden because of too negative feedback, click <a href=# class=show-bad-comment-link>here</a> to view it</div>\").appendTo(\r\n e.find(\".right\")\r\n );\r\n e.find(\".comment-content\").hide();\r\n e.find(\".show-bad-comment-link\").click(function () {\r\n e.find(\".comment-content\").show();\r\n e.find(\".bad-comment-replacement\").hide();\r\n return false;\r\n });\r\n });\r\n });\n </script>\n </div>\r\n\r\n <style type=\"text/css\">\r\n .new-comments-box {\r\n padding: 0.5em;\r\n width: 22px;\r\n font-size: 1.3rem;\r\n font-weight: bold !important;\r\n\r\n position: fixed;\r\n top: 40%;\r\n right: 0;\r\n opacity: 0.2;\r\n color: white;\r\n text-align: center;\r\n\r\n border: 1px solid #222;\r\n background-color: #888 !important;\r\n border-radius: 3px;\r\n -moz-border-radius: 3px;\r\n -webkit-border-radius: 3px;\r\n }\r\n\r\n .new-comments-box:hover {\r\n opacity: 1;\r\n }\r\n\r\n .new-comments-box .dir:hover {\r\n background: #3B5998 !important;\r\n cursor: pointer;\r\n }\r\n </style>\r\n\r\n <div class=\"new-comments-box\" data-position=\"outside\" data-index=\"-1\" style=\"display: none;\">\r\n <div class=\"up dir\" title=\"Ctrl+Up\">↑<hr/>\r\n </div>\r\n <div class=\"info\" title=\"New comments\"></div>\r\n <div class=\"down dir\" title=\"Ctrl+Down\">\r\n <hr/>↓\r\n </div>\r\n </div>\r\n\r\n <script>\r\n $(\".show-archived-checkbox\").change(function () {\r\n const checked = $(this).is(\":checked\");\r\n $.post(\"/data/comment-data\", {action: \"setShowArchived\", checked}, function (json) {\r\n if (json[\"success\"] !== \"true\") {\r\n alert(json[\"error\"]);\r\n } else {\r\n if (checked) {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are now displayed\")\r\n } else {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are no longer displayed\")\r\n }\r\n }\r\n });\r\n return false;\r\n });\r\n\r\n function gotoComment(direction) {\r\n var box = $(\".new-comments-box\");\r\n var index = parseInt(box.attr(\"data-index\"));\r\n if (index == -1)\r\n index = 0;\r\n else\r\n index = Math.max(0, Math.min(parseInt(box.find(\".info\").text()) - 1, index + direction));\r\n box.attr(\"data-index\", index);\r\n var comment = $($(\".comment .highlight-blue[commentId]\").get(index));\r\n $('html, body').animate({\r\n 'scrollTop': Math.max(0, comment.offset().top - ($(window).height() - comment.height()) / 2)\r\n });\r\n return false;\r\n }\r\n\r\n $(\".new-comments-box .down\").click(function () {\r\n return gotoComment(1);\r\n });\r\n\r\n $(\".new-comments-box .up\").click(function () {\r\n return gotoComment(-1);\r\n });\r\n\r\n $(document).keydown(function (e) {\r\n var code = (e.keyCode ? e.keyCode : e.which);\r\n if (e.ctrlKey) {\r\n if (code == 38 || code == 40) {\r\n gotoComment(code - 39);\r\n }\r\n }\r\n });\r\n\r\n var newCommentCount = $(\".comment .highlight-blue[commentId]\").length;\r\n if (newCommentCount > 0) {\r\n $(\".new-comments-box .info\").text(newCommentCount);\r\n $(\".new-comments-box\").show();\r\n }\r\n\r\n $('table.comment-table').mouseenter(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").addClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n\r\n $('table.comment-table').mouseleave(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").removeClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n </script>\r\n\r\n\r\n\r\n <script>\r\n function adjustTopicComplainFrames() {\r\n let topicIds = [];\r\n\r\n $(\".has-topic-id\").each(function () {\r\n const $this = $(this);\r\n const topicId = $this.attr(\"topicId\");\r\n if (topicId) {\r\n topicIds.push(topicId);\r\n }\r\n });\r\n\r\n $.post(\"/data/topics\", {\r\n action: \"findComplainableTopicIds\",\r\n topicIds: topicIds.join(\",\")\r\n }, function (json) {\r\n if (json[\"success\"] === \"true\") {\r\n for (const topicId of json[\"complainableTopicIds\"].split(\",\")) {\r\n $(\".has-topic-id[topicId=\" + topicId + \"]\").each(function () {\r\n $(this).find(\".meta .ComplaintFrame\").css(\"display\", \"inline-block\");\r\n });\r\n }\r\n }\r\n }, \"json\");\r\n }\r\n\r\n $(function () {\r\n adjustTopicComplainFrames();\r\n })\r\n </script>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-10684\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 10684, _tta: Codeforces.tta(), topicRevisionId: 36670, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-10684\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 10684, _tta: Codeforces.tta(), topicRevisionId: 36670, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n </div>\r\n </div>\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 22:13:07</span> (h1).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/81027/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/81027/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/81027/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/81027/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-81027.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'812875a2ab4016f4',t:'MTY5NjcwNTk4Ny4yMjQwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"}}},{"rowIdx":1966,"cells":{"problem_id":{"kind":"string","value":"389D"},"contest":{"kind":"string","value":"389"},"problem":{"kind":"string","value":"D"},"lang":{"kind":"string","value":"en"},"problem_title":{"kind":"string","value":"D. Fox and Minimal path"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">D. Fox and Minimal path</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Fox Ciel wants to write a task for a programming contest. The task is: \"You are given a simple undirected graph with <span class=\"tex-span\"><i>n</i></span> vertexes. Each its edge has unit length. You should calculate the number of shortest paths between vertex 1 and vertex 2.\"</p><p>Same with some writers, she wants to make an example with some certain output: for example, her birthday or the number of her boyfriend. Can you help her to make a test case with answer equal exactly to <span class=\"tex-span\"><i>k</i></span>?</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains a single integer <span class=\"tex-span\"><i>k</i></span> (<span class=\"tex-span\">1 ≤ <i>k</i> ≤ 10<sup class=\"upper-index\">9</sup></span>).</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>You should output a graph <span class=\"tex-span\"><i>G</i></span> with <span class=\"tex-span\"><i>n</i></span> vertexes (<span class=\"tex-span\">2 ≤ <i>n</i> ≤ 1000</span>). There must be exactly <span class=\"tex-span\"><i>k</i></span> shortest paths between vertex 1 and vertex 2 of the graph.</p><p>The first line must contain an integer <span class=\"tex-span\"><i>n</i></span>. Then adjacency matrix <span class=\"tex-span\"><i>G</i></span> with <span class=\"tex-span\"><i>n</i></span> rows and <span class=\"tex-span\"><i>n</i></span> columns must follow. Each element of the matrix must be '<span class=\"tex-font-style-tt\">N</span>' or '<span class=\"tex-font-style-tt\">Y</span>'. If <span class=\"tex-span\"><i>G</i><sub class=\"lower-index\"><i>ij</i></sub></span> is '<span class=\"tex-font-style-tt\">Y</span>', then graph <span class=\"tex-span\"><i>G</i></span> has a edge connecting vertex <span class=\"tex-span\"><i>i</i></span> and vertex <span class=\"tex-span\"><i>j</i></span>. Consider the graph vertexes are numbered from 1 to <span class=\"tex-span\"><i>n</i></span>.</p><p>The graph must be undirected and simple: <span class=\"tex-span\"><i>G</i><sub class=\"lower-index\"><i>ii</i></sub></span> = '<span class=\"tex-font-style-tt\">N</span>' and <span class=\"tex-span\"><i>G</i><sub class=\"lower-index\"><i>ij</i></sub> = <i>G</i><sub class=\"lower-index\"><i>ji</i></sub></span> must hold. And there must be at least one path between vertex 1 and vertex 2. It's guaranteed that the answer exists. If there multiple correct answers, you can output any of them. </p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>2</pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>4<br/>NNYY<br/>NNYY<br/>YYNN<br/>YYNN</pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>9</pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>8<br/>NNYYYNNN<br/>NNNNNYYY<br/>YNNNNYYY<br/>YNNNNYYY<br/>YNNNNYYY<br/>NYYYYNNN<br/>NYYYYNNN<br/>NYYYYNNN</pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>1</pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>2<br/>NY<br/>YN</pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>In first example, there are 2 shortest paths: 1-3-2 and 1-4-2.</p><p>In second example, there are 9 shortest paths: 1-3-6-2, 1-3-7-2, 1-3-8-2, 1-4-6-2, 1-4-7-2, 1-4-8-2, 1-5-6-2, 1-5-7-2, 1-5-8-2.</p></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"a4b8355b8d9518282c7012d6e9f8d76f\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - D - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"f7b10a37dac6b25fba992a730cfa3b90bd8afecf\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - D - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/73366/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/73366/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/73366/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/73366/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/73366/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/73366/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/73366/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/73366/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/73366/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/73366/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/73366/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/73366/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/73366/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/73366/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/sidebar-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/a037fe51637846d9c7c725713cd840ea/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='a4b8355b8d9518282c7012d6e9f8d76f'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/73366/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/73366/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fcontest%2F389%2Fproblem%2FD%3Flocale%3Den\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"current\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='a4b8355b8d9518282c7012d6e9f8d76f'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:100%;\"><a style=\"color: black\" href=\"/contest/389\">Codeforces Round 228 (Div. 2)</a></th>\n </tr>\n <tr>\n <td class=\"left bottom\" colspan=\"1\"><span class=\"contest-state-phase\">Finished</span></td>\n </tr>\n </tbody>\n </table>\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Practice?\n <div class=\"top-links\">\n </div>\n </div>\n<div>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Want to solve the contest problems after the official contest ends? Just register for practice and you will be able to submit solutions.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"\" method=\"post\"><input type='hidden' name='csrf_token' value='a4b8355b8d9518282c7012d6e9f8d76f'/>\r\n <input type=\"hidden\" name=\"action\" value=\"registerForPractice\"/>\r\n <input type=\"submit\" name=\"submit\" value=\"Register for practice\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div> \r\n</div>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox ContestVirtualFrame borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Virtual participation <i class=\"sidebar-caption-icon las la-angle-down\"></i>\r\n\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\" \"\r\n\r\n data-page-url=\"/data/sidebarFrames\"\r\n\r\n>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests.\n\nIf you've seen these problems, a virtual contest is not for you - solve these problems in the archive.\n\nIf you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.\n\nNever use someone else's code, read the tutorials or communicate with other person during a virtual contest.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"/contest/389/virtual\" method=\"get\">\r\n <input type=\"submit\" name=\"submit\" value=\"Start virtual contest\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div>\r\n</div>\r\n <script>\r\n $(function () {\r\n $(\".ContestVirtualFrame .sidebar-caption-icon\").click(function() {\r\n $(this).toggleClass(\"la-angle-down la-angle-right\");\r\n const $target = $(this).parent().next();\r\n $target.toggle();\r\n const dataPageUrl = $target.attr(\"data-page-url\");\r\n const collapsed = $(this).hasClass(\"la-angle-right\");\r\n const params = {\r\n action: \"setCollapsed\",\r\n sidebarFrameSimpleClassName: \"ContestVirtualFrame\",\r\n collapsed\r\n };\r\n $.each($target[0].attributes, function(i, a) {\r\n const name = a.name;\r\n if (name.startsWith(\"data-extra-key-\")) {\r\n const key = a.value;\r\n const keyIndex = parseInt(name.substring(\"data-extra-key-\".length));\r\n const value = $target.attr(\"data-extra-value-\" + keyIndex);\r\n params[key] = value;\r\n }\r\n });\r\n $.post(dataPageUrl, params, function (result) {\r\n if (result[\"success\"] !== \"true\") {\r\n Codeforces.showMessage(\"Failed to save collapsed state.\");\r\n }\r\n }, \"json\");\r\n return false;\r\n });\r\n })\r\n </script>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Problem tags\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Constructive algorithms\">\r\n constructive algorithms\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Graphs\">\r\n graphs\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Implementation problems, programming technics, simulation\">\r\n implementation\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Shortest paths on weighted and unweighted graphs\">\r\n shortest paths\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Difficulty\">\r\n *1900\r\n</span>\r\n </div>\n <div style=\"clear:both;text-align:right;font-size:1.1rem;\">\r\n <span title=\"Please login into the Codeforces\" class=\"notice\">No tag edit access</span>\r\n </div>\r\n</div>\r\n </div>\n\r\n<form id=\"addTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='a4b8355b8d9518282c7012d6e9f8d76f'/>\r\n <input name=\"action\" type=\"hidden\" value=\"addTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"6403\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<form id=\"removeTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='a4b8355b8d9518282c7012d6e9f8d76f'/>\r\n <input name=\"action\" type=\"hidden\" value=\"removeTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"6403\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<script type=\"text/javascript\">\r\n $(\".tag-box img\").click(function () {\r\n var tagName = $(this).attr(\"value\");\r\n Codeforces.confirm(\"Are you sure you want to remove this tag?\", function () {\r\n $(\"#removeTagForm input[name=tagName]\").val(tagName);\r\n $(\"#removeTagForm\").submit();\r\n }, function () {\r\n }, \"Yes\", \"No\");\r\n });\r\n\r\n $(\"#addTagLink\").click(function () {\r\n $(this).hide();\r\n $(\"#addTagLabel\").show();\r\n return false;\r\n });\r\n\r\n $(\"#addTagSelect\").change(function () {\r\n var tagName = $(this).val();\r\n if (tagName === \"\") {\r\n $(\"#addTagLabel\").hide();\r\n $(\"#addTagLink\").show();\r\n } else {\r\n $(\"#addTagForm input[name=tagName]\").val(tagName);\r\n $(\"#addTagForm\").submit();\r\n }\r\n });\r\n</script>\r\n\r\n<style type=\"text/css\">\r\n#new-resource-form tr td {\r\npadding-top: 0.5em;\r\n}\r\n#new-resource-form input:not([type=\"submit\"]) {\r\nfont-size: 0.8em;\r\n}\r\n#new-resource-form select {\r\nfont-size: 0.8em;\r\n}\r\n.new-resource-error {\r\nfont-size: 0.8em;\r\n}\r\n.resource-locale {\r\ncolor: #666;\r\nfont-family: Consolas, \"Andale Mono WT\", \"Andale Mono\", \"Lucida Console\", \"Lucida Sans Typewriter\", \"DejaVu Sans Mono\", \"Bitstream Vera Sans Mono\", \"Liberation Mono\", \"Nimbus Mono L\", Monaco, \"Courier New\", Courier, monospace;\r\n}\r\n</style>\r\n<div class=\"roundbox sidebox sidebar-menu borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Contest materials\n<div class=\"top-links\">\n</div>\n</div>\n<ul>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/10605\" title=\"Codeforces Round #228\" target=\"_blank\">Codeforces Round #228</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"2189:2190\" resourceName=\"Announcement\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/10629\" title=\"Codeforces Round #228 — Editorial\" target=\"_blank\">Tutorial <span class=\"resource-locale\">(en)</span></a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"2191\" resourceName=\"Codeforces Round #228 — Editorial\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n</ul>\r\n</div></div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li class=\"current selectedLava\"><a\r\n href=\"/contest/389\">Problems</a></li>\r\n <li><a\r\n href=\"/contest/389/submit\">Submit Code</a></li>\r\n <li><a\r\n href=\"/contest/389/my\">My Submissions</a></li>\r\n <li><a\r\n href=\"/contest/389/status\">Status</a></li>\r\n <li><a\r\n href=\"/contest/389/hacks\">Hacks</a></li>\r\n <li><a\r\n href=\"/contest/389/room/1\">Room</a></li>\r\n <li><a\r\n href=\"/contest/389/standings\">Standings</a></li>\r\n <li><a\r\n href=\"/contest/389/customtest\">Custom Invocation</a></li>\r\n</ul>\r\n</div>\n\r\n <style>\r\n #facebox .content:has(.diff-popup) {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n }\r\n\r\n .testCaseMarker {\r\n position: absolute;\r\n font-weight: bold;\r\n font-size: 1rem;\r\n }\r\n\r\n .diff-popup {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n display: none;\r\n overflow: auto;\r\n }\r\n\r\n .input-output-copier {\r\n font-size: 1.2rem;\r\n float: right;\r\n color: #888 !important;\r\n cursor: pointer;\r\n border: 1px solid rgb(185, 185, 185);\r\n padding: 3px;\r\n margin: 1px;\r\n line-height: 1.1rem;\r\n text-transform: none;\r\n }\r\n\r\n .input-output-copier:hover {\r\n background-color: #def;\r\n }\r\n\r\n .test-explanation textarea {\r\n width: 100%;\r\n height: 1.5em;\r\n }\r\n\r\n .pending-submission-message {\r\n color: darkorange !important;\r\n }\r\n </style>\r\n <script>\r\n const OPENING_SPACE = String.fromCharCode(1001);\r\n const CLOSING_SPACE = String.fromCharCode(1002);\r\n\r\n const nodeToText = function (node, pre) {\r\n let result = [];\r\n\r\n if (node.tagName === \"SCRIPT\" || node.tagName === \"math\"\r\n || (node.classList && node.classList.contains(\"input-output-copier\")))\r\n return [];\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(OPENING_SPACE);\r\n }\r\n\r\n if (node.nodeType === Node.TEXT_NODE) {\r\n let s = node.textContent;\r\n if (!pre) {\r\n s = s.replace(/\\s+/g, \" \");\r\n }\r\n if (s.length > 0) {\r\n result.push(s);\r\n }\r\n }\r\n\r\n if (pre && node.tagName === \"BR\") {\r\n result.push(\"\\n\");\r\n }\r\n\r\n node.childNodes.forEach(function (child) {\r\n result.push(nodeToText(child, node.tagName === \"PRE\").join(\"\"));\r\n });\r\n\r\n if (node.tagName === \"DIV\"\r\n || node.tagName === \"P\"\r\n || node.tagName === \"PRE\"\r\n || node.tagName === \"UL\"\r\n || node.tagName === \"LI\"\r\n ) {\r\n result.push(\"\\n\");\r\n }\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(CLOSING_SPACE);\r\n }\r\n\r\n return result;\r\n }\r\n\r\n const isSpecial = function (c) {\r\n return c === ',' || c === '.' || c === ';' || c === ')' || c === ' ';\r\n }\r\n\r\n const convertStatementToText = function(statmentNode) {\r\n const text = nodeToText(statmentNode, false).join(\"\").replace(/ +/g, \" \").replace(/\\n\\n+/g, \"\\n\\n\");\r\n let result = [];\r\n for (let i = 0; i < text.length; i++) {\r\n const c = text.charAt(i);\r\n if (c === OPENING_SPACE) {\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"D\" data-uuid=\"ps_f870a48c5a858be0abfeb0ba594b076adeed6480\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">D. Fox and Minimal path</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Fox Ciel wants to write a task for a programming contest. The task is: "You are given a simple undirected graph with <span class=\"tex-span\"><i>n</i></span> vertexes. Each its edge has unit length. You should calculate the number of shortest paths between vertex 1 and vertex 2."</p><p>Same with some writers, she wants to make an example with some certain output: for example, her birthday or the number of her boyfriend. Can you help her to make a test case with answer equal exactly to <span class=\"tex-span\"><i>k</i></span>?</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains a single integer <span class=\"tex-span\"><i>k</i></span> (<span class=\"tex-span\">1 ≤ <i>k</i> ≤ 10<sup class=\"upper-index\">9</sup></span>).</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>You should output a graph <span class=\"tex-span\"><i>G</i></span> with <span class=\"tex-span\"><i>n</i></span> vertexes (<span class=\"tex-span\">2 ≤ <i>n</i> ≤ 1000</span>). There must be exactly <span class=\"tex-span\"><i>k</i></span> shortest paths between vertex 1 and vertex 2 of the graph.</p><p>The first line must contain an integer <span class=\"tex-span\"><i>n</i></span>. Then adjacency matrix <span class=\"tex-span\"><i>G</i></span> with <span class=\"tex-span\"><i>n</i></span> rows and <span class=\"tex-span\"><i>n</i></span> columns must follow. Each element of the matrix must be '<span class=\"tex-font-style-tt\">N</span>' or '<span class=\"tex-font-style-tt\">Y</span>'. If <span class=\"tex-span\"><i>G</i><sub class=\"lower-index\"><i>ij</i></sub></span> is '<span class=\"tex-font-style-tt\">Y</span>', then graph <span class=\"tex-span\"><i>G</i></span> has a edge connecting vertex <span class=\"tex-span\"><i>i</i></span> and vertex <span class=\"tex-span\"><i>j</i></span>. Consider the graph vertexes are numbered from 1 to <span class=\"tex-span\"><i>n</i></span>.</p><p>The graph must be undirected and simple: <span class=\"tex-span\"><i>G</i><sub class=\"lower-index\"><i>ii</i></sub></span> = '<span class=\"tex-font-style-tt\">N</span>' and <span class=\"tex-span\"><i>G</i><sub class=\"lower-index\"><i>ij</i></sub> = <i>G</i><sub class=\"lower-index\"><i>ji</i></sub></span> must hold. And there must be at least one path between vertex 1 and vertex 2. It's guaranteed that the answer exists. If there multiple correct answers, you can output any of them. </p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>2</pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>4<br />NNYY<br />NNYY<br />YYNN<br />YYNN</pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>9</pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>8<br />NNYYYNNN<br />NNNNNYYY<br />YNNNNYYY<br />YNNNNYYY<br />YNNNNYYY<br />NYYYYNNN<br />NYYYYNNN<br />NYYYYNNN</pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>1</pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>2<br />NY<br />YN</pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>In first example, there are 2 shortest paths: 1-3-2 and 1-4-2.</p><p>In second example, there are 9 shortest paths: 1-3-6-2, 1-3-7-2, 1-3-8-2, 1-4-6-2, 1-4-7-2, 1-4-8-2, 1-5-6-2, 1-5-7-2, 1-5-8-2.</p></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=D]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== statementText) {\r\n $problem.find(\".diff-notifier\").show();\r\n\r\n $problem.find(\".diff-notifier-close\").click(function() {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n $problem.find(\".diff-notifier\").hide();\r\n });\r\n\r\n $problem.find(\"a.view-changes\").click(function() {\r\n $.post(\"/data/diff\", {action: \"getDiff\", a: previousStatementText, b: statementText}, function (result) {\r\n if (result[\"success\"] === \"true\") {\r\n Codeforces.facebox(\".diff-popup\", \"//codeforces.org/s/73366\");\r\n $(\"#facebox .diff-popup\").html(result[\"diff\"]);\r\n }\r\n }, \"json\");\r\n });\r\n }\r\n } else {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n }\r\n });\r\n });\r\n </script>\r\n\r\n\r\n<script type=\"text/javascript\">\r\n $(document).ready(function () {\r\n window.changedTests = new Set();\r\n\r\n function endsWith(string, suffix) {\r\n return string.indexOf(suffix, string.length - suffix.length) !== -1;\r\n }\r\n\r\n const inputFileDiv = $(\"div.input-file\");\r\n const inputFile = inputFileDiv.text();\r\n const outputFileDiv = $(\"div.output-file\");\r\n const outputFile = outputFileDiv.text();\r\n\r\n\r\n if (!endsWith(inputFile, \"standard input\")\r\n && !endsWith(inputFile, \"standard input\")) {\r\n inputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n if (!endsWith(outputFile, \"standard output\")\r\n && !endsWith(outputFile, \"standard output\")) {\r\n outputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n const titleDiv = $(\"div.header div.title\");\r\n\r\n\r\n\r\n String.prototype.replaceAll = function (search, replace) {\r\n return this.split(search).join(replace);\r\n };\r\n\r\n $(\".sample-test .title\").each(function () {\r\n const preId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n const cpyId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n\r\n $(this).parent().find(\"pre\").attr(\"id\", preId);\r\n const $copy = $(\"<div title='Copy' data-clipboard-target='#\" + preId + \"' id='\" + cpyId + \"' class='input-output-copier'>Copy</div>\");\r\n $(this).append($copy);\r\n\r\n const clipboard = new Clipboard('#' + cpyId, {\r\n text: function (trigger) {\r\n const pre = document.querySelector('#' + preId);\r\n const lines = pre.querySelectorAll(\".test-example-line\");\r\n return Codeforces.filterClipboardText(pre.innerText, lines.length);\r\n }\r\n });\r\n\r\n const isInput = $(this).parent().hasClass(\"input\");\r\n\r\n clipboard.on('success', function (e) {\r\n if (isInput) {\r\n Codeforces.showMessage(\"The example input has been copied into the clipboard\");\r\n } else {\r\n Codeforces.showMessage(\"The example output has been copied into the clipboard\");\r\n }\r\n e.clearSelection();\r\n });\r\n });\r\n\r\n $(\".test-form-item input\").change(function () {\r\n addPendingSubmissionMessage($($(this).closest(\"form\")), \"You changed the answer, do not forget to submit it if you want to save the changes\");\r\n const index = $(this).closest(\".problemindexholder\").attr(\"problemindex\");\r\n let test = \"\";\r\n $(this).closest(\"form input\").each(function () {\r\n const test_ = $(this).attr(\"name\");\r\n if (test_ && test_.substring(0, 4) === \"test\") {\r\n test = test_;\r\n }\r\n });\r\n if (index.length > 0 && test.length > 0) {\r\n const indexTest = index + \"::\" + test;\r\n window.changedTests.add(indexTest);\r\n }\r\n });\r\n\r\n $(window).on('beforeunload', function () {\r\n if (window.changedTests.size > 0) {\r\n return 'Dialog text here';\r\n }\r\n });\r\n\r\n autosize($('.test-explanation textarea'));\r\n\r\n $(\".test-example-line\").hover(function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n let top = 1E20;\r\n let left = 1E20;\r\n let problem = $(this).closest(\".problemindexholder\");\r\n $(this).closest(\".input\").find(\".\" + clazz).css(\"background-color\", \"#FFFDE7\").each(function() {\r\n top = Math.min(top, $(this).offset().top);\r\n left = Math.min(left, $(this).offset().left);\r\n });\r\n let testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n if (testCaseMarker.length === 0) {\r\n const html = \"<div class=\\\"testCaseMarker testCaseMarker_\" + end + \" notice\\\"></div>\";\r\n problem.append($(html));\r\n testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n }\r\n if (testCaseMarker) {\r\n testCaseMarker.show()\r\n .offset({top, left: left - 20})\r\n .text(end);\r\n }\r\n }\r\n }\r\n });\r\n }, function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n $(\".\" + clazz).css(\"background-color\", \"\");\r\n $(this).closest(\".problemindexholder\").find(\".testCaseMarker_\" + end).hide();\r\n }\r\n }\r\n });\r\n });\r\n\r\n });\r\n</script>\r\n\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 05:38:40</span> (j3).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/73366/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/73366/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/73366/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/73366/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-73366.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'8122c4ed99dd9d64',t:'MTY5NjY0NjMyMC4zMjgwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"},"long_tags":{"kind":"string","value":"[\"Constructive algorithms\", \"Graphs\", \"Implementation problems, programming technics, simulation\", \"Shortest paths on weighted and unweighted graphs\"]"},"short_tags":{"kind":"string","value":"[\"constructive algorithms\", \"graphs\", \"implementation\", \"shortest paths\", \"*1900\"]"},"tutorial_link":{"kind":"string","value":"https://codeforces.com/blog/entry/10629"},"tutorial_page":{"kind":"string","value":"\r\n\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"74361418aed3add319d25ce966ceafdf\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"h1\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Codeforces Round #228 — Editorial - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n \n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Codeforces Round #228 — Editorial - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/81027/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/81027/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/81027/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/81027/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/81027/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/81027/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/81027/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/81027/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/81027/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/81027/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/81027/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/81027/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/81027/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/81027/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/573cedc6b04c15481941f418269f4057/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='74361418aed3add319d25ce966ceafdf'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/81027/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fblog%2Fentry%2F10629\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='74361418aed3add319d25ce966ceafdf'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Pay attention\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n <div style=\"text-align:center;border-bottom: 1px solid rgb(185, 185, 185);margin:0 -0.5em 0.5em -0.5em;padding: 0 1em 0.5em 1em;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 1, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:51:54</span><br/><a href=\"/contestRegistration/1876\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n <div style=\"text-align:center;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 2, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:51:54</span><br/><a href=\"/contestRegistration/1877\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='74361418aed3add319d25ce966ceafdf'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n </label>\r\n </div>\r\n <div style=\"padding: 0 1em 1em 1em;text-align:right;\">\r\n <input style=\"height:1.65em;padding:0 0.75em;\" type=\"submit\" value=\"Find\"/>\r\n </div>\r\n </form>\r\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".handleBox\").autocomplete(\"/data/handles\", {\r\n delay: 200,\r\n width: 200,\r\n selectFirst: false,\r\n matchContains: true,\r\n minChars: 3\r\n });\r\n $(\".handleForm\").attr(\"autocomplete\", \"off\").submit(function () {\r\n var link = \"/profile/userHandle\".replace(\r\n \"userHandle\", $(this).find(\".handleBox\").val()\r\n );\r\n window.location = link;\r\n return false;\r\n });\r\n });\n </script>\n\r\n\r\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Recent actions\n <div class=\"top-links\">\n </div>\n </div>\n <div class=\"recent-actions\">\r\n <ul>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/121073\">Meta Hacker Cup 2023 Round 1</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/.Danet\" title=\"Expert .Danet\" class=\"rated-user user-blue\">.Danet</a> →\r\n <a href=\"/blog/entry/121172\">[TLE on pretest1]</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\" class=\"rated-user user-red\">Pyqe</a> →\r\n <a href=\"/blog/entry/121025\">Codeforces Round #902 (Div. 1, Div. 2, based on COMPFEST 15 — Final Round)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pranshu_Pandya\" title=\"Specialist Pranshu_Pandya\" class=\"rated-user user-cyan\">Pranshu_Pandya</a> →\r\n <a href=\"/blog/entry/121171\">An Interesting Tree Problem</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/sszcdjr\" title=\"Master sszcdjr\" class=\"rated-user user-orange\">sszcdjr</a> →\r\n <a href=\"/blog/entry/119859\">Codeforces Round 896 (Div. 1, Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/119880\">It's Happening! Meta Hacker Cup 2023 Schedule</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/DaviddeGea1\" title=\"Expert DaviddeGea1\" class=\"rated-user user-blue\">DaviddeGea1</a> →\r\n <a href=\"/blog/entry/70917\">Number of ways of dividing an array into 2 parts such that sum of each part is > k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bekh\" title=\"Master Bekh\" class=\"rated-user user-orange\">Bekh</a> →\r\n <a href=\"/blog/entry/74245\">Questions and doubts regarding Aliens DP trick</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a> →\r\n <a href=\"/blog/entry/8192\">Codeforces Round #190 — Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/hocky\" title=\"Candidate Master hocky\" class=\"rated-user user-violet\">hocky</a> →\r\n <a href=\"/blog/entry/95323\">FBHC wuining uw Day? Incwease uw stacc size! (ㅅ´ ˘ `)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/liouzhou_101\" title=\"International Master liouzhou_101\" class=\"rated-user user-orange\">liouzhou_101</a> →\r\n <a href=\"/blog/entry/87598\">Editorial of Codeforces Round #700</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/yeon_gist\" title=\"Newbie yeon_gist\" class=\"rated-user user-gray\">yeon_gist</a> →\r\n <a href=\"/blog/entry/121170\">plusMinusPermutation computing error</a>\r\n <img alt=\"Text created or updated\" title=\"Text created or updated\" src=\"//codeforces.org/s/81027/images/icons/x-update-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/altforminuscontribution\" title=\"Newbie altforminuscontribution\" class=\"rated-user user-gray\">altforminuscontribution</a> →\r\n <a href=\"/blog/entry/121162\">My screen get unexpectedly big, what should I do</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/atcoder_official\" title=\"Unrated, atcoder_official\" class=\"rated-user user-black\">atcoder_official</a> →\r\n <a href=\"/blog/entry/121120\">We will hold UNIQUE VISION Programming Contest 2023 Autumn(AtCoder Beginner Contest 323)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/YouStill_DontKnowMeYet\" title=\"Candidate Master YouStill_DontKnowMeYet\" class=\"rated-user user-violet\">YouStill_DontKnowMeYet</a> →\r\n <a href=\"/blog/entry/117659\">[GYM] Al-Baath Collegiate Programming Contest 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/ankancool\" title=\"Expert ankancool\" class=\"rated-user user-blue\">ankancool</a> →\r\n <a href=\"/blog/entry/121136\">Invitation to AstroByte 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/GeZhiyuan\" title=\"Grandmaster GeZhiyuan\" class=\"rated-user user-red\">GeZhiyuan</a> →\r\n <a href=\"/blog/entry/120943\">Codeforces Round 901 (Div. 1, Div. 2) Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a> →\r\n <a href=\"/blog/entry/120772\">PSA: Increase your stack size before the Meta Hacker Cup, here's how</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/dino_merlin\" title=\"Expert dino_merlin\" class=\"rated-user user-blue\">dino_merlin</a> →\r\n <a href=\"/blog/entry/121145\">Intuitive approach for CEOI Kangaroo?</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/icecuber\" title=\"Grandmaster icecuber\" class=\"rated-user user-red\">icecuber</a> →\r\n <a href=\"/blog/entry/70018\">CSES DP section editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bn00b\" title=\"Newbie Bn00b\" class=\"rated-user user-gray\">Bn00b</a> →\r\n <a href=\"/blog/entry/98820\">[FEATURE REQUEST : ATCODER] TOPICS TAGS AND SORTING BY SOLVE COUNT</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a> →\r\n <a href=\"/blog/entry/121163\">AtCoder Regular Contest 166 Announcement</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/windva\" title=\"Grandmaster windva\" class=\"rated-user user-red\">windva</a> →\r\n <a href=\"/blog/entry/120644\">Codeforces Round 899 (Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Misa-Misa\" title=\"Expert Misa-Misa\" class=\"rated-user user-blue\">Misa-Misa</a> →\r\n <a href=\"/blog/entry/121157\">Someone please help me understand this.</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/shivam565\" title=\"Specialist shivam565\" class=\"rated-user user-cyan\">shivam565</a> →\r\n <a href=\"/blog/entry/108348\">Total number of subarrays with sum atmost k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n </ul>\r\n </div>\r\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/recent-actions\">Detailed →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n</div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li><a\r\n href=\"/profile/cgy4ever\">cgy4ever</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/cgy4ever\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/cgy4ever\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/cgy4ever\">Submissions</a></li>\r\n <li><a\r\n href=\"/groups/with/cgy4ever\">Groups</a></li>\r\n <li><a\r\n href=\"/contests/with/cgy4ever\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/cgy4ever\">Problemsetting</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/cgy4ever\" style=\"text-decoration:none;color:black !important;\">cgy4ever's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"10684\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/10629\"> <p>Codeforces Round #228 — Editorial</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a>,\r\n <span class=\"format-humantime\" title=\"Feb/03/2014 22:14\">10 years ago</span>,\r\n \r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p>You can find the editorial and my solutions here: <a href=\"https://github.com/cgy4ever/CF228\">https://github.com/cgy4ever/CF228</a></p><p><a href=\"/contest/389/problem/A\" title=\"Codeforces Round 228 (Div. 2)\">389A - Fox and Number Game</a></p><p>First we know that: in the optimal solution, all number will be equal: otherwise we can pick a and b (a < b) then do b = b — a, it will make the answer better.</p><p>Then we need an observation: after each operation, the GCD (Greatest common divisor) of all number will remain same. It can be proved by this lemma: if g is a divisor of all number of x[], then after the operation, g is still the divisor of these numbers, and vice versa.</p><p>So in the end, all number will become the GCD of x[].</p><p>Another solution that can pass is: While there exist x[i] > x[j], then do x[i] -= x[j]. We can select arbitrary i and j if there exist more than 1 choice.</p><p><a href=\"/contest/389/problem/B\" title=\"Codeforces Round 228 (Div. 2)\">389B - Fox and Cross</a></p><p>Let's define the first # of a shape is the cell contain # that have the lexicographical smallest coordinate. Then the first # of a cross is the top one.</p><p>Then let x be the first # of the given board. (If the board is empty, then we can draw it with zero crosses.) x must be covered by a cross, and x must be the first # of the cross. (You can try 4 other positions, it will cause a lexicographical smaller # in the board than x)</p><p>So we try to cover this x use one cross, if it leads some part of the cross covers a '.', then there will be no solution. If not, we just reduce the number of # in the board by 4, we can do this again and again.</p><p><a href=\"/contest/389/problem/C\" title=\"Codeforces Round 228 (Div. 2)\">389C - Fox and Box Accumulation</a> / <a href=\"/contest/388/problem/A\" title=\"Codeforces Round 228 (Div. 1)\">388A - Fox and Box Accumulation</a></p><p>We need some observation:</p> <ol> <li><p>There exists an optimal solution such that: in any pile, the box on the higher position will have a smaller strength.</p></li> <li><p>Let k be the minimal number of piles, then there exists an optimal solution such that: The height of all piles is n/k or n/k+1 (if n%k=0, then all of them have the height n/k).</p></li> </ol><p>We can prove them by exchange argument: from an optimal solution, swap the boxes in it to make above property holds, and we can ensure it will remain valid while swapping.</p><p>Then for a given k, we can check whether there exist a solution: the i-th (indexed from 0) smallest strength needs to be at least i/k.</p><p>So we can do binary search (or just enumerate, since n is only 100) on k.</p><p><a href=\"/contest/389/problem/D\" title=\"Codeforces Round 228 (Div. 2)\">389D - Fox and Minimal path</a> / <a href=\"/contest/388/problem/B\" title=\"Codeforces Round 228 (Div. 1)\">388B - Fox and Minimal path</a></p><p>First we need to know how to calculate the number of different shortest paths from vertex 1 to vertex 2: it can be done by dp: dp[1] = 1, dp[v] = sum{dp[t] | dist(1,t) = dist(1,v) — 1}, then dp[2] is our answer.</p><p>We need to do dp layer by layer. (first we consider vertexes have distance 1 to node 1, then vertexes have distance 2 to node 1 and so on.) So we can construct the graph layer by layer, and link edges to control the dp value of it.</p><p>My solution is construct the answer by binary express: If k is 19, then we need some vertexes in previous layer such that the dp value is 16, 2 and 1. So we just need a way to construct layer with dp value equals to 2^k.</p><p>In the first layer, it contains one node: 1, it has the dp value 1. In the next layer, we can construct 2 nodes, with dp value equals to 1. (We use [1 1] to denote it). And the next layer is [1 1 2], then [1 1 2 4], [1 1 2 4 8] and so on. So we need about 30 layers such that gets all 2^k where k < 30. It uses about 500 nodes.</p><p><a href=\"/contest/389/problem/E\" title=\"Codeforces Round 228 (Div. 2)\">389E - Fox and Card Game</a> / <a href=\"/contest/388/problem/C\" title=\"Codeforces Round 228 (Div. 1)\">388C - Fox and Card Game</a></p><p>First let's consider the case which all piles have even size. In this case, we can prove: in the optimal play, Ciel will gets all top most half cards of each pile, and Jiro gets the remain cards.</p><p>We can prove by these facts: Ciel have a strategy to ensure she can get this outcome and Jiro also have a strategy to ensure this outcome. (For Jiro this strategy is easy: just pick the card from pile that Ciel have just picked. For Ciel it's a little bit harder.)</p><p>Why we can conclude they are both the optimal strategy? Ciel just can't win more, because if she played with Jiro with above strategy, Jiro will get the bottom half of each pile.</p><p>Then we come back with cases that contain odd size piles. The result is: for odd size pile, Ciel will get the top (s-1)/2 cards and Jiro will get the bottom (s-1)/2 cards. Then what about the middle one? Let's denote S is all such middle cards. Then we define a reduced game: In each turn, they pick one card from S. The optimal play for this game is easy: Ciel gets the max one, and Jiro gets the 2nd largest one, and Ciel gets the 3rd largest one and so on.</p><p>We can prove Ciel have a strategy to get: all top half parts + cards she will get in the optimal play in the reduced game. And Jiro also have a strategy to get: all bottom half parts + cards he will get in the optimal play in the reduced game. And these strategy are optimal.</p><p><a href=\"/contest/388/problem/D\" title=\"Codeforces Round 228 (Div. 1)\">388D - Fox and Perfect Sets</a></p><p>A perfect set correspond to a linear space, so we can use base to represent it. We do the Gauss–Jordan elimination of vectors in that set, and can get an unique base. (Note that we need to to the all process of Gauss–Jordan elimination, including the elimination after it reached upper triangular)</p><p>And we can construct the bases bit by bit from higher bit to lower, for a bit:</p> <ol> <li><p>We can add a vector to the base such that the bit is the highest bit of that vector. And at this time, all other vector will have 0 in this bit.</p></li> <li><p>Otherwise we need to assign this bit of each vector already in the base. If now we have k vector, then we have 2^k choices.</p></li> </ol><p>And when we do this, we need to know what's the maximal vector in this space. It's not hard:</p> <ol> <li><p>If we add a vector, then in the maximal vector, this bit will be 1.</p></li> <li><p>Otherwise, if we don't have any vector in base yet, then this bit will be 0. Otherwise there will be 2^(k-1) choices results in this bit of maximal vector will be 0, and 2^(k-1) choices results in 1.</p></li> </ol><p>So we can solve this task by DP bit by bit.</p><p><a href=\"/contest/388/problem/E\" title=\"Codeforces Round 228 (Div. 1)\">388E - Fox and Meteor Shower</a></p><p>All tasks beside this are very easy to code. And this one focus on implementation.</p><p>We can represent the orbit of each meteor by a line in 3D space. (we use an axis to represent the time, and two axis to represent the position on the plane.)</p><p>Then the problem becomes: we have some lines in 3D space (they are not complete coincide), find a largest clique such that each pair of lines touch at some point.</p><p>We need this observation: If there are 3 lines in the optimal clique, and these 3 lines are not share a common point, then all line in this clique will on a plane.</p><p>By using this observation, we only need to consider 2 cases:</p> <ol> <li><p>All lines in the clique have a common point.</p></li> <li><p>All lines in the clique are on the same plane.</p></li> </ol><p>Both are easy tasks in theory, but it needs some coding.</p><p>There are two ways:</p> <ol> <li><p>Use integer anywhere. Note that the coordinates of intersection can be rational number, but can't be irrational, so we could do this. We can use some way to encode the plane, direction.</p></li> <li><p>Use floating number. To count same number of points, we can sort (x, y, z) by using the following compare function: if (abs(A.x — B.x) > eps){return A.x < B.x} otherwise { if(abs(A.y-B.y)>eps){return A.y < B.y} otherwise return A.z < B.z}.</p></li> </ol></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/388\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 228 (Div. 1)</a> </span>\r\n </div>\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/389\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 228 (Div. 2)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-21-10684\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"21\",\n blogEntryId: \"10629\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-10684\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+45</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-10684\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/cgy4ever\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/cgy4ever\">\n cgy4ever\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Feb/03/2014 22:14\">10 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/10629#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/10629#comments\">\n 44\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"10700\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (39)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159842\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/YaleZ\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/24526/avatar/5b17db1affad55a5.jpg'/> </a>\n <div><a href=\"/profile/YaleZ\" title=\"Expert YaleZ\" class=\"rated-user user-blue\">YaleZ</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2014 22:38\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159842\" href=\"?#comment-159842\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"159842\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"159842\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"24526\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159842\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thank for timely editorial. I think Markdown is better when publish something on Github. Isn't it?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159842 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159842 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159842\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159846\" commentParentId=\"159842\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/cgy4ever\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2014 22:43\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159846\" href=\"?#comment-159846\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159842\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159846\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"11\"\r\n data-commentUserId=\"62\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+11</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159846\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Yes, I'm working on it. :)</p><p>The website seems to be not stable at this time. So I post them in other sites to ensure all people can see it.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159846 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159846 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159846\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159857\" commentParentId=\"159846\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Nodir.Daminov\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/71439/avatar/d6d2016f6dfe5ecd.jpg'/> </a>\n <div><a href=\"/profile/Nodir.Daminov\" title=\"Candidate Master Nodir.Daminov\" class=\"rated-user user-violet\">Nodir.Daminov</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2014 22:58\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159857\" href=\"?#comment-159857\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159846\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159857\" class=\"CommentVoteFrame\"\r\n class=\"too-negative-comment-vote\"\r\n data-commentRating=\"-35\"\r\n data-commentUserId=\"71439\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-35</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159857\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Maaan is it so hard to COPY ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159857 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159857 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159857\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159874\" commentParentId=\"159857\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/cgy4ever\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2014 23:19\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159874\" href=\"?#comment-159874\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159857\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159874\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"12\"\r\n data-commentUserId=\"62\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+12</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159874\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Sorry for the delay.</p><p>When I was submitting my post that contains the editorial, it always returns "Codeforces is now unavailable." so I just can't post it.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159874 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159874 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159874\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159859\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/BishalG\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/60637/avatar/d21ddf49bbd1630c.jpg'/> </a>\n <div><a href=\"/profile/BishalG\" title=\"Expert BishalG\" class=\"rated-user user-blue\">BishalG</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2014 22:58\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159859\" href=\"?#comment-159859\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159859\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"60637\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159859\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Nice problemSets @<a class=\"rated-user user-orange\" href=\"/profile/cgy4ever\" title=\"International Master cgy4ever\">cgy4ever</a> , although I misunderstood the problem-B <a href=\"/contest/389/problem/B\" title=\"Codeforces Round 228 (Div. 2)\">389B - Fox and Cross</a> upto 1 hrs :( </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159859 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159859 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159859\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159867\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Mr.ink\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Mr.ink\" title=\"Expert Mr.ink\" class=\"rated-user user-blue\">Mr.ink</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2014 23:07\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159867\" href=\"?#comment-159867\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159867\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"128876\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159867\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>due to my slow internet speed i can not see your editorial on github because my country internet has problem with https! </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159867 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159867 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159867\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159881\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Mr.ink\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Mr.ink\" title=\"Expert Mr.ink\" class=\"rated-user user-blue\">Mr.ink</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2014 23:38\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159881\" href=\"?#comment-159881\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159881\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"128876\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159881\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>does anyone have a better solution for div2 C problem?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159881 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159881 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159881\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159883\" commentParentId=\"159881\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/t_thirupathi\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/146179/avatar/98c28348196ce4ca.jpg'/> </a>\n <div><a href=\"/profile/t_thirupathi\" title=\"Specialist t_thirupathi\" class=\"rated-user user-cyan\">t_thirupathi</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2014 23:42\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159883\" href=\"?#comment-159883\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159881\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159883\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"146179\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159883\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Have a look at mine <a href=\"/contest/389/submission/5878414\" title=\"Submission 5878414 by t_thirupathi\">5878414</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159883 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159883 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159883\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159909\" commentParentId=\"159883\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/9charles\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/119814/avatar/653156a3153bc2dd.jpg'/> </a>\n <div><a href=\"/profile/9charles\" title=\"Expert 9charles\" class=\"rated-user user-blue\">9charles</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 06:46\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159909\" href=\"?#comment-159909\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159883\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159909\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"119814\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159909\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can you explain it?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159909 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159909 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159909\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159907\" commentParentId=\"159881\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/k790alex\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/119882/avatar/4baeddca65b2b958.jpg'/> </a>\n <div><a href=\"/profile/k790alex\" title=\"Specialist k790alex\" class=\"rated-user user-cyan\">k790alex</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 06:28\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159907\" href=\"?#comment-159907\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159881\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159907\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"119882\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159907\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I don't know if this is a better way but I didt in the contest.</p><p>Start making a pile with the low strength and while possible, look for a box that can support at least 1 box, then at least 2 boxes, 3, etc, repeat it while you have boxes.</p><p>My solution: <a href=\"/contest/389/submission/5879464\" title=\"Submission 5879464 by k790alex\">5879464</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159907 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159907 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159907\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159914\" commentParentId=\"159907\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/YaleZ\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/24526/avatar/5b17db1affad55a5.jpg'/> </a>\n <div><a href=\"/profile/YaleZ\" title=\"Expert YaleZ\" class=\"rated-user user-blue\">YaleZ</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 07:38\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159914\" href=\"?#comment-159914\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159907\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159914\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"24526\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159914\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Greedy is also a nice solution.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159914 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159914 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159914\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159932\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/worfzyq\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/157364/avatar/8f104a361ed91be8.jpg'/> </a>\n <div><a href=\"/profile/worfzyq\" title=\"Expert worfzyq\" class=\"rated-user user-blue\">worfzyq</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 09:52\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159932\" href=\"?#comment-159932\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159932\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"157364\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159932\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>388C — Fox and Card Game This problem is good magic</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159932 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159932 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159932\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159935\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/orchidmajumder\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/63603/avatar/f8db3747466a7168.jpg'/> </a>\n <div><a href=\"/profile/orchidmajumder\" title=\"Specialist orchidmajumder\" class=\"rated-user user-cyan\">orchidmajumder</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 10:07\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159935\" href=\"?#comment-159935\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"159935\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"159935\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"7\"\r\n data-commentUserId=\"63603\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+7</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159935\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>hii everyone,in Div II E,I can't understand why the optimal play for JIRO is to take the bottom most card from the same pile from where CIEL is picking?should not it try to pick the maximum value among all bottom most card at it's every move??</p><p>Please someone explain why the strategy presented in the editorial is optimal.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159935 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159935 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159935\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159948\" commentParentId=\"159935\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Zzyzx\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/86049/avatar/c698ee674460e7eb.jpg'/> </a>\n <div><a href=\"/profile/Zzyzx\" title=\"Expert Zzyzx\" class=\"rated-user user-blue\">Zzyzx</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 13:07\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159948\" href=\"?#comment-159948\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159935\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159948\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"86049\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159948\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Ok, I'm afraid I do not have a rigorous proof for this. I'll just explain to you why I think it is right.</p><p>First of all, we need to understand that both Ciel and Jiro are smart. Now, whenever it is Ciel's turn, he will pick the "best pile" and try to take everything from that pile and then move on to the next "best pile". Jiro knows that his friend Ciel is smart, so he will try to stop him from taking everything. This can be done only if he picks from the same pile that Ciel does.</p><p>But your question is — what if there is a different pile whose bottom-most card is much better than the bottom-most card of the pile from which Ciel is picking right?</p><p>My answer to this is that, this situation will never arise. Because if there is such a pile, then Ciel will try to take that card in the first place and therefore, Ciel will be picking from the same pile that Jiro will want to pick from.</p><p>Am I making sense? Or is there a flaw in my argument?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159948 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159948 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159948\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159952\" commentParentId=\"159948\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/orchidmajumder\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/63603/avatar/f8db3747466a7168.jpg'/> </a>\n <div><a href=\"/profile/orchidmajumder\" title=\"Specialist orchidmajumder\" class=\"rated-user user-cyan\">orchidmajumder</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 13:32\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159952\" href=\"?#comment-159952\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159948\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159952\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"63603\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159952\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Yes I'm also thinking along the same line.Both are playing optimally and if Ciel is chosing any pile then jiro knows that this pile has better cards in the botttom half.So he won't choose ciel to take the advantage and vice versa.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159952 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159952 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159952\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159944\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hzyfr\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/hzyfr\" title=\"Expert hzyfr\" class=\"rated-user user-blue\">hzyfr</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 12:27\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159944\" href=\"?#comment-159944\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159944\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"129936\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159944\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I have a different idea on D div1 <a href=\"/contest/388/problem/D\" title=\"Codeforces Round 228 (Div. 1)\">388D - Fox and Perfect Sets</a> but I failed on getting some relations in one step.</p><p>Let <em>M</em> be the maximum element in set <em>S</em> . Then if <em>S</em> is a perfect set, its elements should have all bits equals <em>0</em> on positions in <em>M's</em> binary representation(otherwise there must exist another element bigger than <em>M</em>). So let <em>cnt</em> = (number of 1's in binary repersentation of <em>M</em>), then the number of perfect sets which has <em>M</em> as its greatest element is determined by <em>cnt</em> . Well, this is the step I can't come up with a solution(actually the target is to find the number of perfect sets which has <code>2^cnt-1</code> as its greatest element).</p><p>Then the last step is simple. We can apply something like doubling algorithm on the problem.</p><p>We are asked to find the number of perfect sets with all the elements not greater than <em>N</em> . Let's suppose <em>N+1</em> is a power of 2 then its easy to calculate how many numbers not greater than <em>N</em> has <em>cnt</em> = 1,2,...m where m is the length of <em>N</em> in binary representation. That's just simple combinatoric number <em>C(n,i) (1<=i<=n)</em> . And if we have done the previous step, it's easy to get the result.</p><p>Then think about common cases of <em>N</em> . Let's take the highest bit of N and since all above bits are determined, the number of 1's will just add a constant value. So calculate this part and subtract that highest bit of <em>N</em> and do the same thing on remaining value of <em>N</em> , until <em>N=0</em> . At that time we will get the correct answer. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159944 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159944 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159944\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159945\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/rexdf\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/23738/avatar/797fa665fbe1ca78.jpg'/> </a>\n <div><a href=\"/profile/rexdf\" title=\"Specialist rexdf\" class=\"rated-user user-cyan\">rexdf</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 12:36\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159945\" href=\"?#comment-159945\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159945\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"23738\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159945\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>dp[1] = 1, dp[v] = sum{dp[t] | dist(1,t) = dist(1,v) — 1}, then dp[2] is our answer. What's v means? what's '|' means? What's dp[v] means?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159945 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159945 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159945\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159949\" commentParentId=\"159945\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/sancho\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/85894/avatar/e31a4b24327c1000.jpg'/> </a>\n <div><a href=\"/profile/sancho\" title=\"Candidate Master sancho\" class=\"rated-user user-violet\">sancho</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 13:10\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159949\" href=\"?#comment-159949\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159945\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159949\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"85894\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159949\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>v — vertex, answer for which we are getting at this moment, | — means "such as", dp[v] — number of ways from 1 vertex to this one</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159949 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159949 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159949\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159947\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lol12\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/lol12\" title=\"Specialist lol12\" class=\"rated-user user-cyan\">lol12</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 13:04\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159947\" href=\"?#comment-159947\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159947\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"10\"\r\n data-commentUserId=\"152356\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+10</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159947\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can someone please explain solution of Div2-D. Thanx</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159947 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159947 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159947\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"160020\" commentParentId=\"159947\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/YaleZ\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/24526/avatar/5b17db1affad55a5.jpg'/> </a>\n <div><a href=\"/profile/YaleZ\" title=\"Expert YaleZ\" class=\"rated-user user-blue\">YaleZ</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/05/2014 07:07\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-160020\" href=\"?#comment-160020\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159947\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"160020\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"9\"\r\n data-commentUserId=\"24526\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+9</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-160020\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>You can think about binnary. Such as (13)10=(1101)2=((1+(2+0)*2)+1)*2+1</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-160020 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-160020 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-160020\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"469976\" commentParentId=\"159947\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/roll_no_1\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/631859/avatar/36d157f91f64fe7f.jpg'/> </a>\n <div><a href=\"/profile/roll_no_1\" title=\"Master roll_no_1\" class=\"rated-user user-orange\">roll_no_1</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Nov/09/2018 17:27\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-469976\" href=\"?#comment-469976\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159947\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"469976\" revisionCount=\"4\" revision=\"4\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">4</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"469976\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"631859\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-469976\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Here's my implementation of the editorialist's explanation of Div-2 D / Div-1 B: <a href=\"/contest/388/submission/45480077\" title=\"Submission 45480077 by roll_no_1\">45480077</a>. I implemented the layers as [1], [1, 1], [2, 1, 1], [4, 2, 1, 1] and so on.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-469976 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-469976 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-469976\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159967\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/BENYAM1N\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/84938/avatar/d2ae2657d8898e38.jpg'/> </a>\n <div><a href=\"/profile/BENYAM1N\" title=\"Master BENYAM1N\" class=\"rated-user user-orange\">BENYAM1N</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 15:51\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159967\" href=\"?#comment-159967\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159967\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"13\"\r\n data-commentUserId=\"84938\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+13</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159967\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Very good contest and nice editorial. Hope from now on I see more contests from you.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159967 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159967 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159967\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159984\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/kojak_\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/57722/avatar/38990eea59bc188e.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/kojak_\" title=\"Newbie kojak_\" class=\"rated-user user-gray\">kojak_</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 18:34\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159984\" href=\"?#comment-159984\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159984\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"57722\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159984\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Did anyone come up with a DP solution for Div.2 C/ Div.1 A?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159984 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159984 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159984\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"160012\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/IgorKoval\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/51322/avatar/afc854fff49f072a.jpg'/> </a>\n <div><a href=\"/profile/IgorKoval\" title=\"Candidate Master IgorKoval\" class=\"rated-user user-violet\">IgorKoval</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 23:17\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-160012\" href=\"?#comment-160012\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"160012\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"11\"\r\n data-commentUserId=\"51322\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+11</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-160012\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Объясните, пожалуйста, разбор задачи "388D — Fox and Perfect Sets" на пальцах. Как-нибудь без Гаусса и базисов. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-160012 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-160012 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-160012\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"160016\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Mr.ink\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Mr.ink\" title=\"Expert Mr.ink\" class=\"rated-user user-blue\">Mr.ink</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/05/2014 01:08\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-160016\" href=\"?#comment-160016\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"160016\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"128876\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-160016\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>fox and card games is a great problem.thanks!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-160016 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-160016 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-160016\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"160037\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/yaswanth\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/yaswanth\" title=\"Specialist yaswanth\" class=\"rated-user user-cyan\">yaswanth</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/05/2014 18:38\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-160037\" href=\"?#comment-160037\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"160037\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"9\"\r\n data-commentUserId=\"96196\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+9</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-160037\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can anyone explain div2 C question? I did not understand the editorial.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-160037 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-160037 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-160037\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"160063\" commentParentId=\"160037\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/YaleZ\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/24526/avatar/5b17db1affad55a5.jpg'/> </a>\n <div><a href=\"/profile/YaleZ\" title=\"Expert YaleZ\" class=\"rated-user user-blue\">YaleZ</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/06/2014 05:46\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-160063\" href=\"?#comment-160063\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-160037\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"160063\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"24526\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-160063\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>s[i]>=i/k -> k*s[i]>=i There are i boxes' strength smaller than i-th box. So we need to check if the boxes before i-th can be held.</p><p>(I don't know whether I have understood correctly...)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-160063 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-160063 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-160063\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"160053\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/yada\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/142663/avatar/49901b54d1c5f019.jpg'/> </a>\n <div><a href=\"/profile/yada\" title=\"Candidate Master yada\" class=\"rated-user user-violet\">yada</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/05/2014 23:24\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-160053\" href=\"?#comment-160053\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"160053\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"142663\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-160053\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Great Problem! I really enjoy it.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-160053 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-160053 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-160053\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"364019\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lnzva\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/305672/avatar/cf6c09a214141751.jpg'/> </a>\n <div><a href=\"/profile/lnzva\" title=\"Expert lnzva\" class=\"rated-user user-blue\">lnzva</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/02/2017 22:06\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-364019\" href=\"?#comment-364019\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"364019\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"364019\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"305672\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-364019\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In 388C, I'm having a hard time understanding why Jiro's optimal strategy would be to pick the pile Ciel just picked. Why not pick a pile which has a better bottom part than the one Ciel is picking? According to some comments, Ciel would then pick from the second pile-what if another pile has a much better top part? Could someone please help? I saw this problem first 6 months ago, and I had a hard time understanding why this greedy is correct; I saw this problem again today and am having trouble with it again, with no progress.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-364019 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-364019 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-364019\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"647866\" commentParentId=\"364019\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/_wzx27\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1458283/avatar/7d77b62012ae2398.jpg'/> </a>\n <div><a href=\"/profile/_wzx27\" title=\"Candidate Master _wzx27\" class=\"rated-user user-violet\">_wzx27</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/22/2020 18:33\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-647866\" href=\"?#comment-647866\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-364019\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"647866\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1458283\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-647866\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Let's consider such a two-piles situation:</p><p><em>111100</em></p><p><em>001111</em></p><p>is better for Ciel.</p><p>"1" means this card is picked by Ciel,while "0" by Jiro.</p><p>We know that better for Ciel means worse for Jiro.</p><p>So if</p><p><em>111100</em></p><p><em>001111</em></p><p>is better than</p><p><em>111000</em></p><p><em>000111</em></p><p>for Ciel.</p><p>Then when Ciel picked the <strong>first three cards</strong> from <strong>pile 1</strong>,Jiro can just pick the <strong>last three cards</strong> from <strong>pile 1</strong> and finally lead to the result:</p><p><em>111000</em></p><p><em>000111</em></p><p>which is not better for Ciel.</p><p>Generally, if the final result is not balance(half from top and half from bottom) while balance is better than such result for Jiro, Jiro has the ability to adjust it to be balance.So do Ciel.</p><p>Therefore,it reaches balance.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-647866 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-647866 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-647866\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"407776\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/madhur4127\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/568692/avatar/c7d62cc23c758819.jpg'/> </a>\n <div><a href=\"/profile/madhur4127\" title=\"Specialist madhur4127\" class=\"rated-user user-cyan\">madhur4127</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/15/2018 13:06\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-407776\" href=\"?#comment-407776\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"407776\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"568692\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-407776\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>@<a class=\"rated-user user-red\" href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\">cgy4ever</a>, github link shows 404 error(Page not found). Kindly fix it.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-407776 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-407776 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-407776\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"416354\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/introverted\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/657339/avatar/7a6edb1ecc1d3e09.jpg'/> </a>\n <div><a href=\"/profile/introverted\" title=\"Expert introverted\" class=\"rated-user user-blue\">introverted</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/23/2018 11:48\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-416354\" href=\"?#comment-416354\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"416354\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"657339\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-416354\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I solved the DIV1B problem with simple recursion and Divide and Conquer.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-416354 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-416354 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-416354\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"427890\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Nuu\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/652228/avatar/d59867d6477379dc.jpg'/> </a>\n <div><a href=\"/profile/Nuu\" title=\"Candidate Master Nuu\" class=\"rated-user user-violet\">Nuu</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/01/2018 22:33\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-427890\" href=\"?#comment-427890\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"427890\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"652228\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-427890\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can anyone give me some examples of the similar problems to DivC?? I think this problem is very nice for train brain xD</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-427890 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-427890 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-427890\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"629609\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/The_Alchemist\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1275181/avatar/662970aa05d3dfc5.jpg'/> </a>\n <div><a href=\"/profile/The_Alchemist\" title=\"Expert The_Alchemist\" class=\"rated-user user-blue\">The_Alchemist</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/25/2020 21:47\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-629609\" href=\"?#comment-629609\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"629609\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1275181\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-629609\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I know I am very late but can someone pls explain to me div 2C/div1A. Thanks in advance... </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-629609 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-629609 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-629609\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"641010\" commentParentId=\"629609\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/kstheking\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1160931/avatar/e144fc7b0fdb90b1.jpg'/> </a>\n <div><a href=\"/profile/kstheking\" title=\"Pupil kstheking\" class=\"rated-user user-green\">kstheking</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/13/2020 14:47\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-641010\" href=\"?#comment-641010\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-629609\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"641010\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1160931\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-641010\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p><a href=\"https://codeforces.com/contest/388/submission/83605110\">https://codeforces.com/contest/388/submission/83605110</a> Here you go, if you don't get it feel free to ask</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-641010 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-641010 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-641010\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"644488\" commentParentId=\"641010\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/tanisha_\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/tanisha_\" title=\"Newbie tanisha_\" class=\"rated-user user-gray\">tanisha_</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/18/2020 15:26\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-644488\" href=\"?#comment-644488\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-641010\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"644488\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1500127\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-644488\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>is this any algorithm</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-644488 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-644488 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-644488\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"647627\" commentParentId=\"644488\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/kstheking\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1160931/avatar/e144fc7b0fdb90b1.jpg'/> </a>\n <div><a href=\"/profile/kstheking\" title=\"Pupil kstheking\" class=\"rated-user user-green\">kstheking</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/22/2020 08:40\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-647627\" href=\"?#comment-647627\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-644488\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"647627\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"647627\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1160931\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-647627\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Well you can call it a greedy algorithm, when we try to apply greedy by placing the heaviest block in bottom, a little problem occurs because of blocks of same strength for example in case of 10 2 2 1 1 0 0<br />If you try to apply greedy by choosing the strongest block<br />10 2 2 1<br />1 0<br />0<br />= 3 heaps<br />Which is wrong answer as sometimes we lose opportunity to create lesser heaps, as in this case if we use the second 2 to make another heap we can do better<br />10 2 1 0<br />2 1 0<br />= 2 heaps<br />So I apply greedy in the reverse direction by picking the smallest strength brick and placing below it the next smallest brick, this way the optimal number of heaps will be formed as in above example<br />choose 0, then you need >= 1, choose 1, then you need >= 2, choose 2, then you need >= 3 choose 10<br />repeat until you have chosen all the bricks<br />If you don't get anything, feel free to ask :) </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-647627 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-647627 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-647627\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"702677\" commentParentId=\"647627\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/breddreamer\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/853067/avatar/240684624b57996.jpg'/> </a>\n <div><a href=\"/profile/breddreamer\" title=\"Newbie breddreamer\" class=\"rated-user user-gray\">breddreamer</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/27/2020 13:01\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-702677\" href=\"?#comment-702677\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-647627\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"702677\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"853067\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-702677\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks, It helped me to understand your solution idea. And finally, I solved this one.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-702677 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-702677 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-702677\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"649225\" commentParentId=\"641010\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/The_Alchemist\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1275181/avatar/662970aa05d3dfc5.jpg'/> </a>\n <div><a href=\"/profile/The_Alchemist\" title=\"Expert The_Alchemist\" class=\"rated-user user-blue\">The_Alchemist</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/24/2020 12:04\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-649225\" href=\"?#comment-649225\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-641010\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"649225\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1275181\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-649225\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>thank you.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-649225 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-649225 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-649225\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n <br/>\r\n\r\n<div id=\"editBox-10700\" style=\"width:50em;display:none;\">\r\n <div class=\"previewBody\" style=\"border: 1px solid #d4d4d4; margin-bottom: 0.5em; padding: 0.25em; display:none;\"> </div>\r\n <div style=\"width: 1px\"> </div>\r\n <div class=\"commentLocale\" style=\"position: relative; top: 0.5em;left:4px;display: none;\">\r\n <input type=\"radio\" name=\"locale\" value=\"en\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In English</span>\r\n <input style=\"margin-left:1em\" type=\"radio\" name=\"locale\" value=\"ru\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In Russian</span>\r\n </div>\r\n <textarea data-drafts-id=\"CommentReplyFrame\" class=\"wysiwyg\" name=\"editContent\" rows=\"20\" style=\"width:99%;\"></textarea>\r\n <div class=\"error error__content\"></div>\r\n <div style=\"text-align:center;\">\r\n <input type=\"button\" name=\"preview\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Preview\"/>\r\n <input type=\"button\" name=\"save\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Save\"/>\r\n </div>\r\n</div>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n\r\nvar firstPreview10700 = true;\r\nvar lastPreviewContent10700 = '';\r\n\r\nif (!window.moveCommentRevision) {\r\n moveCommentRevision = function(e, dir) {\r\n var p = e.parent();\r\n var revisionCount = parseInt(p.attr(\"revisionCount\"));\r\n var revision = parseInt(p.attr(\"revision\"));\r\n var next = revision + dir;\r\n var commentId = p.attr(\"commentId\");\r\n if (next >= 1 && next <= revisionCount) {\r\n $.post(\r\n \"/data/comment-data\",\r\n {action: \"revision\", commentId: commentId, revision: next},\r\n function(json) {\r\n if (json.success == \"true\") {\r\n var parentDiv = e;\r\n\r\n while (parentDiv !== null && (parentDiv[0].nodeName.toLowerCase() !== \"td\" || !parentDiv.hasClass(\"right\"))) {\r\n parentDiv = parentDiv.parent();\r\n }\r\n\r\n if (parentDiv === null) {\r\n return;\r\n }\r\n\r\n parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\").html(json.content);\r\n Codeforces.setupSpoilers(parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\"));\r\n p.attr(\"revision\", next);\r\n p.find(\"span.revision\").text(next);\r\n if (next == 1) {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"visible\");\r\n }\r\n if (next == revisionCount) {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"visible\");\r\n }\r\n\r\n window.updateTypography();\r\n MathJax.Hub.Typeset();\r\n } else {\r\n alert(e.error);\r\n }\r\n },\r\n \"json\"\r\n );\r\n }\r\n };\r\n}\r\n\r\n$(\"div[commentableId=10700] a.leftRevision\").click(function () {\r\n window.moveCommentRevision($(this), -1);\r\n return false;\r\n});\r\n\r\n$(\"div[commentableId=10700] a.rightRevision\").click(function () {\r\n window.moveCommentRevision($(this), +1);\r\n return false;\r\n});\r\n\r\n\r\n\r\n });\n </script>\n\r\n\r\n <script src=\"//codeforces.org/s/81027/js/swfobject-2.2.min.js\" type=\"text/javascript\"></script>\n <script src=\"//codeforces.org/s/81027/js/ftaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n if (window.evercookie) {\n var ec = new evercookie({\n history: false,\n silverlight: false,\n baseurl: '',\n asseturi: '/assets',\n phpuri: '/2fdcd78',\n pngPath: '/eps',\n etagPath: '/ees',\n cachePath: '/ecs'\n });\n\n var randomNumber = function () {\n return Math.random().toString(36).substr(2);\n };\n\n var randomToken = function () {\n return (randomNumber() + randomNumber()).substring(0, 18);\n };\n\n window._ftaa = \"\";\n\n ec.get(\"70a7c28f3de\", function (value) {\n window._ftaa = value;\n if (!window._ftaa) {\n window._ftaa = randomToken();\n ec.set(\"70a7c28f3de\", window._ftaa);\n }\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n } else {\n window._ftaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\n <script src=\"//codeforces.org/s/81027/js/bfaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n var fpCallback = function() {\n Fingerprint2.get({}, function(components) {\n window._bfaa = Fingerprint2.x64hash128(components.map(function (pair) { return pair.value }).join(), 31);\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n };\n if (typeof Fingerprint2 !== 'undefined') {\n if (window.requestIdleCallback) {\n requestIdleCallback(fpCallback)\n } else {\n setTimeout(fpCallback, 500)\n }\n } else {\n window._bfaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"a.new-root-comment\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n\r\n $(\".comment-table .reply a\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".vote-for-comment\").mouseover(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").mouseout(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").click(function () {\r\n var vote = $(this);\r\n var commentId = $(this).parent().attr(\"commentid\");\r\n var commentRating = $(this).parent().attr(\"data-commentRating\");\r\n var direction = $(this).attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n $.post(\"/data/comment/vote\", {commentId: commentId, _tta: Codeforces.tta(), vote: direction, commentRating: commentRating}, function(data) {\r\n if (direction != 0 && !ownComment && data[\"success\"] == \"true\") {\r\n vote.parent().find(\".vote-for-comment\").attr(\"voteDirection\", 0);\r\n if (direction == 1)\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n else {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.closest(\".CommentVoteFrame\").find(\".ComplaintFrame\").css(\"display\", \"inline-block\");\r\n }\r\n vote.find(\"img\").attr(\"popacity\", \"1.0\");\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n vote.parent().find(\".commentRating\").html(data[\"commentRating\"]);\r\n }\r\n Codeforces.showMessage(data[\"message\"]);\r\n }, \"json\");\r\n return false;\r\n });\r\n\r\n $(\".negative-comment-vote\").closest(\".comment-table\").addClass(\"comment-bad\");\r\n\r\n $(\".troll-comment-vote\").closest(\".comment\").css(\"display\", \"none\");\r\n\r\n $(\".too-negative-comment-vote\").closest(\".comment-table\").each(function () {\r\n var e = $(this);\r\n e.addClass(\"comment-too-bad\");\r\n var commentId = e.attr(\"commentId\");\r\n $(\"<div class='bad-comment-replacement ttypography'>The comment is hidden because of too negative feedback, click <a href=# class=show-bad-comment-link>here</a> to view it</div>\").appendTo(\r\n e.find(\".right\")\r\n );\r\n e.find(\".comment-content\").hide();\r\n e.find(\".show-bad-comment-link\").click(function () {\r\n e.find(\".comment-content\").show();\r\n e.find(\".bad-comment-replacement\").hide();\r\n return false;\r\n });\r\n });\r\n });\n </script>\n </div>\r\n\r\n <style type=\"text/css\">\r\n .new-comments-box {\r\n padding: 0.5em;\r\n width: 22px;\r\n font-size: 1.3rem;\r\n font-weight: bold !important;\r\n\r\n position: fixed;\r\n top: 40%;\r\n right: 0;\r\n opacity: 0.2;\r\n color: white;\r\n text-align: center;\r\n\r\n border: 1px solid #222;\r\n background-color: #888 !important;\r\n border-radius: 3px;\r\n -moz-border-radius: 3px;\r\n -webkit-border-radius: 3px;\r\n }\r\n\r\n .new-comments-box:hover {\r\n opacity: 1;\r\n }\r\n\r\n .new-comments-box .dir:hover {\r\n background: #3B5998 !important;\r\n cursor: pointer;\r\n }\r\n </style>\r\n\r\n <div class=\"new-comments-box\" data-position=\"outside\" data-index=\"-1\" style=\"display: none;\">\r\n <div class=\"up dir\" title=\"Ctrl+Up\">↑<hr/>\r\n </div>\r\n <div class=\"info\" title=\"New comments\"></div>\r\n <div class=\"down dir\" title=\"Ctrl+Down\">\r\n <hr/>↓\r\n </div>\r\n </div>\r\n\r\n <script>\r\n $(\".show-archived-checkbox\").change(function () {\r\n const checked = $(this).is(\":checked\");\r\n $.post(\"/data/comment-data\", {action: \"setShowArchived\", checked}, function (json) {\r\n if (json[\"success\"] !== \"true\") {\r\n alert(json[\"error\"]);\r\n } else {\r\n if (checked) {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are now displayed\")\r\n } else {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are no longer displayed\")\r\n }\r\n }\r\n });\r\n return false;\r\n });\r\n\r\n function gotoComment(direction) {\r\n var box = $(\".new-comments-box\");\r\n var index = parseInt(box.attr(\"data-index\"));\r\n if (index == -1)\r\n index = 0;\r\n else\r\n index = Math.max(0, Math.min(parseInt(box.find(\".info\").text()) - 1, index + direction));\r\n box.attr(\"data-index\", index);\r\n var comment = $($(\".comment .highlight-blue[commentId]\").get(index));\r\n $('html, body').animate({\r\n 'scrollTop': Math.max(0, comment.offset().top - ($(window).height() - comment.height()) / 2)\r\n });\r\n return false;\r\n }\r\n\r\n $(\".new-comments-box .down\").click(function () {\r\n return gotoComment(1);\r\n });\r\n\r\n $(\".new-comments-box .up\").click(function () {\r\n return gotoComment(-1);\r\n });\r\n\r\n $(document).keydown(function (e) {\r\n var code = (e.keyCode ? e.keyCode : e.which);\r\n if (e.ctrlKey) {\r\n if (code == 38 || code == 40) {\r\n gotoComment(code - 39);\r\n }\r\n }\r\n });\r\n\r\n var newCommentCount = $(\".comment .highlight-blue[commentId]\").length;\r\n if (newCommentCount > 0) {\r\n $(\".new-comments-box .info\").text(newCommentCount);\r\n $(\".new-comments-box\").show();\r\n }\r\n\r\n $('table.comment-table').mouseenter(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").addClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n\r\n $('table.comment-table').mouseleave(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").removeClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n </script>\r\n\r\n\r\n\r\n <script>\r\n function adjustTopicComplainFrames() {\r\n let topicIds = [];\r\n\r\n $(\".has-topic-id\").each(function () {\r\n const $this = $(this);\r\n const topicId = $this.attr(\"topicId\");\r\n if (topicId) {\r\n topicIds.push(topicId);\r\n }\r\n });\r\n\r\n $.post(\"/data/topics\", {\r\n action: \"findComplainableTopicIds\",\r\n topicIds: topicIds.join(\",\")\r\n }, function (json) {\r\n if (json[\"success\"] === \"true\") {\r\n for (const topicId of json[\"complainableTopicIds\"].split(\",\")) {\r\n $(\".has-topic-id[topicId=\" + topicId + \"]\").each(function () {\r\n $(this).find(\".meta .ComplaintFrame\").css(\"display\", \"inline-block\");\r\n });\r\n }\r\n }\r\n }, \"json\");\r\n }\r\n\r\n $(function () {\r\n adjustTopicComplainFrames();\r\n })\r\n </script>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-10684\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 10684, _tta: Codeforces.tta(), topicRevisionId: 36670, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-10684\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 10684, _tta: Codeforces.tta(), topicRevisionId: 36670, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n </div>\r\n </div>\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 22:13:07</span> (h1).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/81027/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/81027/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/81027/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/81027/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-81027.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'812875a2ab4016f4',t:'MTY5NjcwNTk4Ny4yMjQwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"}}},{"rowIdx":1967,"cells":{"problem_id":{"kind":"string","value":"389E"},"contest":{"kind":"string","value":"389"},"problem":{"kind":"string","value":"E"},"lang":{"kind":"string","value":"en"},"problem_title":{"kind":"string","value":"E. Fox and Card Game"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">E. Fox and Card Game</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Fox Ciel is playing a card game with her friend Fox Jiro. There are <span class=\"tex-span\"><i>n</i></span> piles of cards on the table. And there is a positive integer on each card.</p><p>The players take turns and Ciel takes the first turn. In Ciel's turn she takes a card from the top of any non-empty pile, and in Jiro's turn he takes a card from the bottom of any non-empty pile. Each player wants to maximize the total sum of the cards he took. The game ends when all piles become empty.</p><p>Suppose Ciel and Jiro play optimally, what is the score of the game?</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contain an integer <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">1 ≤ <i>n</i> ≤ 100</span>). Each of the next <span class=\"tex-span\"><i>n</i></span> lines contains a description of the pile: the first integer in the line is <span class=\"tex-span\"><i>s</i><sub class=\"lower-index\"><i>i</i></sub></span> (<span class=\"tex-span\">1 ≤ <i>s</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 100</span>) — the number of cards in the <span class=\"tex-span\"><i>i</i></span>-th pile; then follow <span class=\"tex-span\"><i>s</i><sub class=\"lower-index\"><i>i</i></sub></span> positive integers <span class=\"tex-span\"><i>c</i><sub class=\"lower-index\">1</sub></span>, <span class=\"tex-span\"><i>c</i><sub class=\"lower-index\">2</sub></span>, ..., <span class=\"tex-span\"><i>c</i><sub class=\"lower-index\"><i>k</i></sub></span>, ..., <span class=\"tex-span\"><i>c</i><sub class=\"lower-index\"><i>s</i><sub class=\"lower-index\"><i>i</i></sub></sub></span> (<span class=\"tex-span\">1 ≤ <i>c</i><sub class=\"lower-index\"><i>k</i></sub> ≤ 1000</span>) — the sequence of the numbers on the cards listed from top of the current pile to bottom of the pile.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print two integers: the sum of Ciel's cards and the sum of Jiro's cards if they play optimally.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>2<br/>1 100<br/>2 1 10<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>101 10<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>1<br/>9 2 8 6 5 9 4 7 1 3<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>30 15<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3<br/>3 1 3 2<br/>3 5 4 6<br/>2 8 7<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>18 18<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3<br/>3 1000 1000 1000<br/>6 1000 1000 1000 1000 1000 1000<br/>5 1000 1000 1000 1000 1000<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>7000 7000<br/></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>In the first example, Ciel will take the cards with number 100 and 1, Jiro will take the card with number 10.</p><p>In the second example, Ciel will take cards with numbers 2, 8, 6, 5, 9 and Jiro will take cards with numbers 4, 7, 1, 3.</p></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"6063b7b3a3f13001e3b5d9bbb31e59df\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - E - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"f7b10a37dac6b25fba992a730cfa3b90bd8afecf\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - E - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/73366/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/73366/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/73366/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/73366/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/73366/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/73366/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/73366/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/73366/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/73366/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/73366/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/73366/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/73366/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/73366/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/73366/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/sidebar-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/a037fe51637846d9c7c725713cd840ea/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='6063b7b3a3f13001e3b5d9bbb31e59df'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/73366/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/73366/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fcontest%2F389%2Fproblem%2FE%3Flocale%3Den\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"current\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='6063b7b3a3f13001e3b5d9bbb31e59df'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:100%;\"><a style=\"color: black\" href=\"/contest/389\">Codeforces Round 228 (Div. 2)</a></th>\n </tr>\n <tr>\n <td class=\"left bottom\" colspan=\"1\"><span class=\"contest-state-phase\">Finished</span></td>\n </tr>\n </tbody>\n </table>\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Practice?\n <div class=\"top-links\">\n </div>\n </div>\n<div>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Want to solve the contest problems after the official contest ends? Just register for practice and you will be able to submit solutions.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"\" method=\"post\"><input type='hidden' name='csrf_token' value='6063b7b3a3f13001e3b5d9bbb31e59df'/>\r\n <input type=\"hidden\" name=\"action\" value=\"registerForPractice\"/>\r\n <input type=\"submit\" name=\"submit\" value=\"Register for practice\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div> \r\n</div>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox ContestVirtualFrame borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Virtual participation <i class=\"sidebar-caption-icon las la-angle-down\"></i>\r\n\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\" \"\r\n\r\n data-page-url=\"/data/sidebarFrames\"\r\n\r\n>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests.\n\nIf you've seen these problems, a virtual contest is not for you - solve these problems in the archive.\n\nIf you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.\n\nNever use someone else's code, read the tutorials or communicate with other person during a virtual contest.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"/contest/389/virtual\" method=\"get\">\r\n <input type=\"submit\" name=\"submit\" value=\"Start virtual contest\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div>\r\n</div>\r\n <script>\r\n $(function () {\r\n $(\".ContestVirtualFrame .sidebar-caption-icon\").click(function() {\r\n $(this).toggleClass(\"la-angle-down la-angle-right\");\r\n const $target = $(this).parent().next();\r\n $target.toggle();\r\n const dataPageUrl = $target.attr(\"data-page-url\");\r\n const collapsed = $(this).hasClass(\"la-angle-right\");\r\n const params = {\r\n action: \"setCollapsed\",\r\n sidebarFrameSimpleClassName: \"ContestVirtualFrame\",\r\n collapsed\r\n };\r\n $.each($target[0].attributes, function(i, a) {\r\n const name = a.name;\r\n if (name.startsWith(\"data-extra-key-\")) {\r\n const key = a.value;\r\n const keyIndex = parseInt(name.substring(\"data-extra-key-\".length));\r\n const value = $target.attr(\"data-extra-value-\" + keyIndex);\r\n params[key] = value;\r\n }\r\n });\r\n $.post(dataPageUrl, params, function (result) {\r\n if (result[\"success\"] !== \"true\") {\r\n Codeforces.showMessage(\"Failed to save collapsed state.\");\r\n }\r\n }, \"json\");\r\n return false;\r\n });\r\n })\r\n </script>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Problem tags\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Greedy algorithms\">\r\n greedy\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Implementation problems, programming technics, simulation\">\r\n implementation\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Difficulty\">\r\n *2000\r\n</span>\r\n </div>\n <div style=\"clear:both;text-align:right;font-size:1.1rem;\">\r\n <span title=\"Please login into the Codeforces\" class=\"notice\">No tag edit access</span>\r\n </div>\r\n</div>\r\n </div>\n\r\n<form id=\"addTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='6063b7b3a3f13001e3b5d9bbb31e59df'/>\r\n <input name=\"action\" type=\"hidden\" value=\"addTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"6404\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<form id=\"removeTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='6063b7b3a3f13001e3b5d9bbb31e59df'/>\r\n <input name=\"action\" type=\"hidden\" value=\"removeTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"6404\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<script type=\"text/javascript\">\r\n $(\".tag-box img\").click(function () {\r\n var tagName = $(this).attr(\"value\");\r\n Codeforces.confirm(\"Are you sure you want to remove this tag?\", function () {\r\n $(\"#removeTagForm input[name=tagName]\").val(tagName);\r\n $(\"#removeTagForm\").submit();\r\n }, function () {\r\n }, \"Yes\", \"No\");\r\n });\r\n\r\n $(\"#addTagLink\").click(function () {\r\n $(this).hide();\r\n $(\"#addTagLabel\").show();\r\n return false;\r\n });\r\n\r\n $(\"#addTagSelect\").change(function () {\r\n var tagName = $(this).val();\r\n if (tagName === \"\") {\r\n $(\"#addTagLabel\").hide();\r\n $(\"#addTagLink\").show();\r\n } else {\r\n $(\"#addTagForm input[name=tagName]\").val(tagName);\r\n $(\"#addTagForm\").submit();\r\n }\r\n });\r\n</script>\r\n\r\n<style type=\"text/css\">\r\n#new-resource-form tr td {\r\npadding-top: 0.5em;\r\n}\r\n#new-resource-form input:not([type=\"submit\"]) {\r\nfont-size: 0.8em;\r\n}\r\n#new-resource-form select {\r\nfont-size: 0.8em;\r\n}\r\n.new-resource-error {\r\nfont-size: 0.8em;\r\n}\r\n.resource-locale {\r\ncolor: #666;\r\nfont-family: Consolas, \"Andale Mono WT\", \"Andale Mono\", \"Lucida Console\", \"Lucida Sans Typewriter\", \"DejaVu Sans Mono\", \"Bitstream Vera Sans Mono\", \"Liberation Mono\", \"Nimbus Mono L\", Monaco, \"Courier New\", Courier, monospace;\r\n}\r\n</style>\r\n<div class=\"roundbox sidebox sidebar-menu borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Contest materials\n<div class=\"top-links\">\n</div>\n</div>\n<ul>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/10605\" title=\"Codeforces Round #228\" target=\"_blank\">Codeforces Round #228</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"2189:2190\" resourceName=\"Announcement\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/10629\" title=\"Codeforces Round #228 — Editorial\" target=\"_blank\">Tutorial <span class=\"resource-locale\">(en)</span></a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"2191\" resourceName=\"Codeforces Round #228 — Editorial\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n</ul>\r\n</div></div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li class=\"current selectedLava\"><a\r\n href=\"/contest/389\">Problems</a></li>\r\n <li><a\r\n href=\"/contest/389/submit\">Submit Code</a></li>\r\n <li><a\r\n href=\"/contest/389/my\">My Submissions</a></li>\r\n <li><a\r\n href=\"/contest/389/status\">Status</a></li>\r\n <li><a\r\n href=\"/contest/389/hacks\">Hacks</a></li>\r\n <li><a\r\n href=\"/contest/389/room/1\">Room</a></li>\r\n <li><a\r\n href=\"/contest/389/standings\">Standings</a></li>\r\n <li><a\r\n href=\"/contest/389/customtest\">Custom Invocation</a></li>\r\n</ul>\r\n</div>\n\r\n <style>\r\n #facebox .content:has(.diff-popup) {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n }\r\n\r\n .testCaseMarker {\r\n position: absolute;\r\n font-weight: bold;\r\n font-size: 1rem;\r\n }\r\n\r\n .diff-popup {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n display: none;\r\n overflow: auto;\r\n }\r\n\r\n .input-output-copier {\r\n font-size: 1.2rem;\r\n float: right;\r\n color: #888 !important;\r\n cursor: pointer;\r\n border: 1px solid rgb(185, 185, 185);\r\n padding: 3px;\r\n margin: 1px;\r\n line-height: 1.1rem;\r\n text-transform: none;\r\n }\r\n\r\n .input-output-copier:hover {\r\n background-color: #def;\r\n }\r\n\r\n .test-explanation textarea {\r\n width: 100%;\r\n height: 1.5em;\r\n }\r\n\r\n .pending-submission-message {\r\n color: darkorange !important;\r\n }\r\n </style>\r\n <script>\r\n const OPENING_SPACE = String.fromCharCode(1001);\r\n const CLOSING_SPACE = String.fromCharCode(1002);\r\n\r\n const nodeToText = function (node, pre) {\r\n let result = [];\r\n\r\n if (node.tagName === \"SCRIPT\" || node.tagName === \"math\"\r\n || (node.classList && node.classList.contains(\"input-output-copier\")))\r\n return [];\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(OPENING_SPACE);\r\n }\r\n\r\n if (node.nodeType === Node.TEXT_NODE) {\r\n let s = node.textContent;\r\n if (!pre) {\r\n s = s.replace(/\\s+/g, \" \");\r\n }\r\n if (s.length > 0) {\r\n result.push(s);\r\n }\r\n }\r\n\r\n if (pre && node.tagName === \"BR\") {\r\n result.push(\"\\n\");\r\n }\r\n\r\n node.childNodes.forEach(function (child) {\r\n result.push(nodeToText(child, node.tagName === \"PRE\").join(\"\"));\r\n });\r\n\r\n if (node.tagName === \"DIV\"\r\n || node.tagName === \"P\"\r\n || node.tagName === \"PRE\"\r\n || node.tagName === \"UL\"\r\n || node.tagName === \"LI\"\r\n ) {\r\n result.push(\"\\n\");\r\n }\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(CLOSING_SPACE);\r\n }\r\n\r\n return result;\r\n }\r\n\r\n const isSpecial = function (c) {\r\n return c === ',' || c === '.' || c === ';' || c === ')' || c === ' ';\r\n }\r\n\r\n const convertStatementToText = function(statmentNode) {\r\n const text = nodeToText(statmentNode, false).join(\"\").replace(/ +/g, \" \").replace(/\\n\\n+/g, \"\\n\\n\");\r\n let result = [];\r\n for (let i = 0; i < text.length; i++) {\r\n const c = text.charAt(i);\r\n if (c === OPENING_SPACE) {\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"E\" data-uuid=\"ps_bf4136bfc169991d4ead5d7424890fc386c88757\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">E. Fox and Card Game</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Fox Ciel is playing a card game with her friend Fox Jiro. There are <span class=\"tex-span\"><i>n</i></span> piles of cards on the table. And there is a positive integer on each card.</p><p>The players take turns and Ciel takes the first turn. In Ciel's turn she takes a card from the top of any non-empty pile, and in Jiro's turn he takes a card from the bottom of any non-empty pile. Each player wants to maximize the total sum of the cards he took. The game ends when all piles become empty.</p><p>Suppose Ciel and Jiro play optimally, what is the score of the game?</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contain an integer <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">1 ≤ <i>n</i> ≤ 100</span>). Each of the next <span class=\"tex-span\"><i>n</i></span> lines contains a description of the pile: the first integer in the line is <span class=\"tex-span\"><i>s</i><sub class=\"lower-index\"><i>i</i></sub></span> (<span class=\"tex-span\">1 ≤ <i>s</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 100</span>) — the number of cards in the <span class=\"tex-span\"><i>i</i></span>-th pile; then follow <span class=\"tex-span\"><i>s</i><sub class=\"lower-index\"><i>i</i></sub></span> positive integers <span class=\"tex-span\"><i>c</i><sub class=\"lower-index\">1</sub></span>, <span class=\"tex-span\"><i>c</i><sub class=\"lower-index\">2</sub></span>, ..., <span class=\"tex-span\"><i>c</i><sub class=\"lower-index\"><i>k</i></sub></span>, ..., <span class=\"tex-span\"><i>c</i><sub class=\"lower-index\"><i>s</i><sub class=\"lower-index\"><i>i</i></sub></sub></span> (<span class=\"tex-span\">1 ≤ <i>c</i><sub class=\"lower-index\"><i>k</i></sub> ≤ 1000</span>) — the sequence of the numbers on the cards listed from top of the current pile to bottom of the pile.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print two integers: the sum of Ciel's cards and the sum of Jiro's cards if they play optimally.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>2<br />1 100<br />2 1 10<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>101 10<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>1<br />9 2 8 6 5 9 4 7 1 3<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>30 15<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3<br />3 1 3 2<br />3 5 4 6<br />2 8 7<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>18 18<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3<br />3 1000 1000 1000<br />6 1000 1000 1000 1000 1000 1000<br />5 1000 1000 1000 1000 1000<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>7000 7000<br /></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>In the first example, Ciel will take the cards with number 100 and 1, Jiro will take the card with number 10.</p><p>In the second example, Ciel will take cards with numbers 2, 8, 6, 5, 9 and Jiro will take cards with numbers 4, 7, 1, 3.</p></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=E]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== statementText) {\r\n $problem.find(\".diff-notifier\").show();\r\n\r\n $problem.find(\".diff-notifier-close\").click(function() {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n $problem.find(\".diff-notifier\").hide();\r\n });\r\n\r\n $problem.find(\"a.view-changes\").click(function() {\r\n $.post(\"/data/diff\", {action: \"getDiff\", a: previousStatementText, b: statementText}, function (result) {\r\n if (result[\"success\"] === \"true\") {\r\n Codeforces.facebox(\".diff-popup\", \"//codeforces.org/s/73366\");\r\n $(\"#facebox .diff-popup\").html(result[\"diff\"]);\r\n }\r\n }, \"json\");\r\n });\r\n }\r\n } else {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n }\r\n });\r\n });\r\n </script>\r\n\r\n\r\n<script type=\"text/javascript\">\r\n $(document).ready(function () {\r\n window.changedTests = new Set();\r\n\r\n function endsWith(string, suffix) {\r\n return string.indexOf(suffix, string.length - suffix.length) !== -1;\r\n }\r\n\r\n const inputFileDiv = $(\"div.input-file\");\r\n const inputFile = inputFileDiv.text();\r\n const outputFileDiv = $(\"div.output-file\");\r\n const outputFile = outputFileDiv.text();\r\n\r\n\r\n if (!endsWith(inputFile, \"standard input\")\r\n && !endsWith(inputFile, \"standard input\")) {\r\n inputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n if (!endsWith(outputFile, \"standard output\")\r\n && !endsWith(outputFile, \"standard output\")) {\r\n outputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n const titleDiv = $(\"div.header div.title\");\r\n\r\n\r\n\r\n String.prototype.replaceAll = function (search, replace) {\r\n return this.split(search).join(replace);\r\n };\r\n\r\n $(\".sample-test .title\").each(function () {\r\n const preId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n const cpyId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n\r\n $(this).parent().find(\"pre\").attr(\"id\", preId);\r\n const $copy = $(\"<div title='Copy' data-clipboard-target='#\" + preId + \"' id='\" + cpyId + \"' class='input-output-copier'>Copy</div>\");\r\n $(this).append($copy);\r\n\r\n const clipboard = new Clipboard('#' + cpyId, {\r\n text: function (trigger) {\r\n const pre = document.querySelector('#' + preId);\r\n const lines = pre.querySelectorAll(\".test-example-line\");\r\n return Codeforces.filterClipboardText(pre.innerText, lines.length);\r\n }\r\n });\r\n\r\n const isInput = $(this).parent().hasClass(\"input\");\r\n\r\n clipboard.on('success', function (e) {\r\n if (isInput) {\r\n Codeforces.showMessage(\"The example input has been copied into the clipboard\");\r\n } else {\r\n Codeforces.showMessage(\"The example output has been copied into the clipboard\");\r\n }\r\n e.clearSelection();\r\n });\r\n });\r\n\r\n $(\".test-form-item input\").change(function () {\r\n addPendingSubmissionMessage($($(this).closest(\"form\")), \"You changed the answer, do not forget to submit it if you want to save the changes\");\r\n const index = $(this).closest(\".problemindexholder\").attr(\"problemindex\");\r\n let test = \"\";\r\n $(this).closest(\"form input\").each(function () {\r\n const test_ = $(this).attr(\"name\");\r\n if (test_ && test_.substring(0, 4) === \"test\") {\r\n test = test_;\r\n }\r\n });\r\n if (index.length > 0 && test.length > 0) {\r\n const indexTest = index + \"::\" + test;\r\n window.changedTests.add(indexTest);\r\n }\r\n });\r\n\r\n $(window).on('beforeunload', function () {\r\n if (window.changedTests.size > 0) {\r\n return 'Dialog text here';\r\n }\r\n });\r\n\r\n autosize($('.test-explanation textarea'));\r\n\r\n $(\".test-example-line\").hover(function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n let top = 1E20;\r\n let left = 1E20;\r\n let problem = $(this).closest(\".problemindexholder\");\r\n $(this).closest(\".input\").find(\".\" + clazz).css(\"background-color\", \"#FFFDE7\").each(function() {\r\n top = Math.min(top, $(this).offset().top);\r\n left = Math.min(left, $(this).offset().left);\r\n });\r\n let testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n if (testCaseMarker.length === 0) {\r\n const html = \"<div class=\\\"testCaseMarker testCaseMarker_\" + end + \" notice\\\"></div>\";\r\n problem.append($(html));\r\n testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n }\r\n if (testCaseMarker) {\r\n testCaseMarker.show()\r\n .offset({top, left: left - 20})\r\n .text(end);\r\n }\r\n }\r\n }\r\n });\r\n }, function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n $(\".\" + clazz).css(\"background-color\", \"\");\r\n $(this).closest(\".problemindexholder\").find(\".testCaseMarker_\" + end).hide();\r\n }\r\n }\r\n });\r\n });\r\n\r\n });\r\n</script>\r\n\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 05:38:41</span> (j3).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/73366/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/73366/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/73366/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/73366/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-73366.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'8122c4f5ae597b3b',t:'MTY5NjY0NjMyMS41OTgwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"},"long_tags":{"kind":"string","value":"[\"Greedy algorithms\", \"Implementation problems, programming technics, simulation\"]"},"short_tags":{"kind":"string","value":"[\"greedy\", \"implementation\", \"*2000\"]"},"tutorial_link":{"kind":"string","value":"https://codeforces.com/blog/entry/10629"},"tutorial_page":{"kind":"string","value":"\r\n\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"74361418aed3add319d25ce966ceafdf\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"h1\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Codeforces Round #228 — Editorial - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n \n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Codeforces Round #228 — Editorial - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/81027/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/81027/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/81027/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/81027/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/81027/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/81027/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/81027/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/81027/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/81027/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/81027/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/81027/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/81027/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/81027/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/81027/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/573cedc6b04c15481941f418269f4057/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='74361418aed3add319d25ce966ceafdf'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/81027/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fblog%2Fentry%2F10629\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='74361418aed3add319d25ce966ceafdf'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Pay attention\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n <div style=\"text-align:center;border-bottom: 1px solid rgb(185, 185, 185);margin:0 -0.5em 0.5em -0.5em;padding: 0 1em 0.5em 1em;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 1, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:51:54</span><br/><a href=\"/contestRegistration/1876\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n <div style=\"text-align:center;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 2, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:51:54</span><br/><a href=\"/contestRegistration/1877\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='74361418aed3add319d25ce966ceafdf'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n </label>\r\n </div>\r\n <div style=\"padding: 0 1em 1em 1em;text-align:right;\">\r\n <input style=\"height:1.65em;padding:0 0.75em;\" type=\"submit\" value=\"Find\"/>\r\n </div>\r\n </form>\r\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".handleBox\").autocomplete(\"/data/handles\", {\r\n delay: 200,\r\n width: 200,\r\n selectFirst: false,\r\n matchContains: true,\r\n minChars: 3\r\n });\r\n $(\".handleForm\").attr(\"autocomplete\", \"off\").submit(function () {\r\n var link = \"/profile/userHandle\".replace(\r\n \"userHandle\", $(this).find(\".handleBox\").val()\r\n );\r\n window.location = link;\r\n return false;\r\n });\r\n });\n </script>\n\r\n\r\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Recent actions\n <div class=\"top-links\">\n </div>\n </div>\n <div class=\"recent-actions\">\r\n <ul>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/121073\">Meta Hacker Cup 2023 Round 1</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/.Danet\" title=\"Expert .Danet\" class=\"rated-user user-blue\">.Danet</a> →\r\n <a href=\"/blog/entry/121172\">[TLE on pretest1]</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\" class=\"rated-user user-red\">Pyqe</a> →\r\n <a href=\"/blog/entry/121025\">Codeforces Round #902 (Div. 1, Div. 2, based on COMPFEST 15 — Final Round)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pranshu_Pandya\" title=\"Specialist Pranshu_Pandya\" class=\"rated-user user-cyan\">Pranshu_Pandya</a> →\r\n <a href=\"/blog/entry/121171\">An Interesting Tree Problem</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/sszcdjr\" title=\"Master sszcdjr\" class=\"rated-user user-orange\">sszcdjr</a> →\r\n <a href=\"/blog/entry/119859\">Codeforces Round 896 (Div. 1, Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/119880\">It's Happening! Meta Hacker Cup 2023 Schedule</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/DaviddeGea1\" title=\"Expert DaviddeGea1\" class=\"rated-user user-blue\">DaviddeGea1</a> →\r\n <a href=\"/blog/entry/70917\">Number of ways of dividing an array into 2 parts such that sum of each part is > k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bekh\" title=\"Master Bekh\" class=\"rated-user user-orange\">Bekh</a> →\r\n <a href=\"/blog/entry/74245\">Questions and doubts regarding Aliens DP trick</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a> →\r\n <a href=\"/blog/entry/8192\">Codeforces Round #190 — Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/hocky\" title=\"Candidate Master hocky\" class=\"rated-user user-violet\">hocky</a> →\r\n <a href=\"/blog/entry/95323\">FBHC wuining uw Day? Incwease uw stacc size! (ㅅ´ ˘ `)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/liouzhou_101\" title=\"International Master liouzhou_101\" class=\"rated-user user-orange\">liouzhou_101</a> →\r\n <a href=\"/blog/entry/87598\">Editorial of Codeforces Round #700</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/yeon_gist\" title=\"Newbie yeon_gist\" class=\"rated-user user-gray\">yeon_gist</a> →\r\n <a href=\"/blog/entry/121170\">plusMinusPermutation computing error</a>\r\n <img alt=\"Text created or updated\" title=\"Text created or updated\" src=\"//codeforces.org/s/81027/images/icons/x-update-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/altforminuscontribution\" title=\"Newbie altforminuscontribution\" class=\"rated-user user-gray\">altforminuscontribution</a> →\r\n <a href=\"/blog/entry/121162\">My screen get unexpectedly big, what should I do</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/atcoder_official\" title=\"Unrated, atcoder_official\" class=\"rated-user user-black\">atcoder_official</a> →\r\n <a href=\"/blog/entry/121120\">We will hold UNIQUE VISION Programming Contest 2023 Autumn(AtCoder Beginner Contest 323)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/YouStill_DontKnowMeYet\" title=\"Candidate Master YouStill_DontKnowMeYet\" class=\"rated-user user-violet\">YouStill_DontKnowMeYet</a> →\r\n <a href=\"/blog/entry/117659\">[GYM] Al-Baath Collegiate Programming Contest 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/ankancool\" title=\"Expert ankancool\" class=\"rated-user user-blue\">ankancool</a> →\r\n <a href=\"/blog/entry/121136\">Invitation to AstroByte 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/GeZhiyuan\" title=\"Grandmaster GeZhiyuan\" class=\"rated-user user-red\">GeZhiyuan</a> →\r\n <a href=\"/blog/entry/120943\">Codeforces Round 901 (Div. 1, Div. 2) Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a> →\r\n <a href=\"/blog/entry/120772\">PSA: Increase your stack size before the Meta Hacker Cup, here's how</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/dino_merlin\" title=\"Expert dino_merlin\" class=\"rated-user user-blue\">dino_merlin</a> →\r\n <a href=\"/blog/entry/121145\">Intuitive approach for CEOI Kangaroo?</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/icecuber\" title=\"Grandmaster icecuber\" class=\"rated-user user-red\">icecuber</a> →\r\n <a href=\"/blog/entry/70018\">CSES DP section editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bn00b\" title=\"Newbie Bn00b\" class=\"rated-user user-gray\">Bn00b</a> →\r\n <a href=\"/blog/entry/98820\">[FEATURE REQUEST : ATCODER] TOPICS TAGS AND SORTING BY SOLVE COUNT</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a> →\r\n <a href=\"/blog/entry/121163\">AtCoder Regular Contest 166 Announcement</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/windva\" title=\"Grandmaster windva\" class=\"rated-user user-red\">windva</a> →\r\n <a href=\"/blog/entry/120644\">Codeforces Round 899 (Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Misa-Misa\" title=\"Expert Misa-Misa\" class=\"rated-user user-blue\">Misa-Misa</a> →\r\n <a href=\"/blog/entry/121157\">Someone please help me understand this.</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/shivam565\" title=\"Specialist shivam565\" class=\"rated-user user-cyan\">shivam565</a> →\r\n <a href=\"/blog/entry/108348\">Total number of subarrays with sum atmost k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n </ul>\r\n </div>\r\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/recent-actions\">Detailed →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n</div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li><a\r\n href=\"/profile/cgy4ever\">cgy4ever</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/cgy4ever\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/cgy4ever\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/cgy4ever\">Submissions</a></li>\r\n <li><a\r\n href=\"/groups/with/cgy4ever\">Groups</a></li>\r\n <li><a\r\n href=\"/contests/with/cgy4ever\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/cgy4ever\">Problemsetting</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/cgy4ever\" style=\"text-decoration:none;color:black !important;\">cgy4ever's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"10684\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/10629\"> <p>Codeforces Round #228 — Editorial</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a>,\r\n <span class=\"format-humantime\" title=\"Feb/03/2014 22:14\">10 years ago</span>,\r\n \r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p>You can find the editorial and my solutions here: <a href=\"https://github.com/cgy4ever/CF228\">https://github.com/cgy4ever/CF228</a></p><p><a href=\"/contest/389/problem/A\" title=\"Codeforces Round 228 (Div. 2)\">389A - Fox and Number Game</a></p><p>First we know that: in the optimal solution, all number will be equal: otherwise we can pick a and b (a < b) then do b = b — a, it will make the answer better.</p><p>Then we need an observation: after each operation, the GCD (Greatest common divisor) of all number will remain same. It can be proved by this lemma: if g is a divisor of all number of x[], then after the operation, g is still the divisor of these numbers, and vice versa.</p><p>So in the end, all number will become the GCD of x[].</p><p>Another solution that can pass is: While there exist x[i] > x[j], then do x[i] -= x[j]. We can select arbitrary i and j if there exist more than 1 choice.</p><p><a href=\"/contest/389/problem/B\" title=\"Codeforces Round 228 (Div. 2)\">389B - Fox and Cross</a></p><p>Let's define the first # of a shape is the cell contain # that have the lexicographical smallest coordinate. Then the first # of a cross is the top one.</p><p>Then let x be the first # of the given board. (If the board is empty, then we can draw it with zero crosses.) x must be covered by a cross, and x must be the first # of the cross. (You can try 4 other positions, it will cause a lexicographical smaller # in the board than x)</p><p>So we try to cover this x use one cross, if it leads some part of the cross covers a '.', then there will be no solution. If not, we just reduce the number of # in the board by 4, we can do this again and again.</p><p><a href=\"/contest/389/problem/C\" title=\"Codeforces Round 228 (Div. 2)\">389C - Fox and Box Accumulation</a> / <a href=\"/contest/388/problem/A\" title=\"Codeforces Round 228 (Div. 1)\">388A - Fox and Box Accumulation</a></p><p>We need some observation:</p> <ol> <li><p>There exists an optimal solution such that: in any pile, the box on the higher position will have a smaller strength.</p></li> <li><p>Let k be the minimal number of piles, then there exists an optimal solution such that: The height of all piles is n/k or n/k+1 (if n%k=0, then all of them have the height n/k).</p></li> </ol><p>We can prove them by exchange argument: from an optimal solution, swap the boxes in it to make above property holds, and we can ensure it will remain valid while swapping.</p><p>Then for a given k, we can check whether there exist a solution: the i-th (indexed from 0) smallest strength needs to be at least i/k.</p><p>So we can do binary search (or just enumerate, since n is only 100) on k.</p><p><a href=\"/contest/389/problem/D\" title=\"Codeforces Round 228 (Div. 2)\">389D - Fox and Minimal path</a> / <a href=\"/contest/388/problem/B\" title=\"Codeforces Round 228 (Div. 1)\">388B - Fox and Minimal path</a></p><p>First we need to know how to calculate the number of different shortest paths from vertex 1 to vertex 2: it can be done by dp: dp[1] = 1, dp[v] = sum{dp[t] | dist(1,t) = dist(1,v) — 1}, then dp[2] is our answer.</p><p>We need to do dp layer by layer. (first we consider vertexes have distance 1 to node 1, then vertexes have distance 2 to node 1 and so on.) So we can construct the graph layer by layer, and link edges to control the dp value of it.</p><p>My solution is construct the answer by binary express: If k is 19, then we need some vertexes in previous layer such that the dp value is 16, 2 and 1. So we just need a way to construct layer with dp value equals to 2^k.</p><p>In the first layer, it contains one node: 1, it has the dp value 1. In the next layer, we can construct 2 nodes, with dp value equals to 1. (We use [1 1] to denote it). And the next layer is [1 1 2], then [1 1 2 4], [1 1 2 4 8] and so on. So we need about 30 layers such that gets all 2^k where k < 30. It uses about 500 nodes.</p><p><a href=\"/contest/389/problem/E\" title=\"Codeforces Round 228 (Div. 2)\">389E - Fox and Card Game</a> / <a href=\"/contest/388/problem/C\" title=\"Codeforces Round 228 (Div. 1)\">388C - Fox and Card Game</a></p><p>First let's consider the case which all piles have even size. In this case, we can prove: in the optimal play, Ciel will gets all top most half cards of each pile, and Jiro gets the remain cards.</p><p>We can prove by these facts: Ciel have a strategy to ensure she can get this outcome and Jiro also have a strategy to ensure this outcome. (For Jiro this strategy is easy: just pick the card from pile that Ciel have just picked. For Ciel it's a little bit harder.)</p><p>Why we can conclude they are both the optimal strategy? Ciel just can't win more, because if she played with Jiro with above strategy, Jiro will get the bottom half of each pile.</p><p>Then we come back with cases that contain odd size piles. The result is: for odd size pile, Ciel will get the top (s-1)/2 cards and Jiro will get the bottom (s-1)/2 cards. Then what about the middle one? Let's denote S is all such middle cards. Then we define a reduced game: In each turn, they pick one card from S. The optimal play for this game is easy: Ciel gets the max one, and Jiro gets the 2nd largest one, and Ciel gets the 3rd largest one and so on.</p><p>We can prove Ciel have a strategy to get: all top half parts + cards she will get in the optimal play in the reduced game. And Jiro also have a strategy to get: all bottom half parts + cards he will get in the optimal play in the reduced game. And these strategy are optimal.</p><p><a href=\"/contest/388/problem/D\" title=\"Codeforces Round 228 (Div. 1)\">388D - Fox and Perfect Sets</a></p><p>A perfect set correspond to a linear space, so we can use base to represent it. We do the Gauss–Jordan elimination of vectors in that set, and can get an unique base. (Note that we need to to the all process of Gauss–Jordan elimination, including the elimination after it reached upper triangular)</p><p>And we can construct the bases bit by bit from higher bit to lower, for a bit:</p> <ol> <li><p>We can add a vector to the base such that the bit is the highest bit of that vector. And at this time, all other vector will have 0 in this bit.</p></li> <li><p>Otherwise we need to assign this bit of each vector already in the base. If now we have k vector, then we have 2^k choices.</p></li> </ol><p>And when we do this, we need to know what's the maximal vector in this space. It's not hard:</p> <ol> <li><p>If we add a vector, then in the maximal vector, this bit will be 1.</p></li> <li><p>Otherwise, if we don't have any vector in base yet, then this bit will be 0. Otherwise there will be 2^(k-1) choices results in this bit of maximal vector will be 0, and 2^(k-1) choices results in 1.</p></li> </ol><p>So we can solve this task by DP bit by bit.</p><p><a href=\"/contest/388/problem/E\" title=\"Codeforces Round 228 (Div. 1)\">388E - Fox and Meteor Shower</a></p><p>All tasks beside this are very easy to code. And this one focus on implementation.</p><p>We can represent the orbit of each meteor by a line in 3D space. (we use an axis to represent the time, and two axis to represent the position on the plane.)</p><p>Then the problem becomes: we have some lines in 3D space (they are not complete coincide), find a largest clique such that each pair of lines touch at some point.</p><p>We need this observation: If there are 3 lines in the optimal clique, and these 3 lines are not share a common point, then all line in this clique will on a plane.</p><p>By using this observation, we only need to consider 2 cases:</p> <ol> <li><p>All lines in the clique have a common point.</p></li> <li><p>All lines in the clique are on the same plane.</p></li> </ol><p>Both are easy tasks in theory, but it needs some coding.</p><p>There are two ways:</p> <ol> <li><p>Use integer anywhere. Note that the coordinates of intersection can be rational number, but can't be irrational, so we could do this. We can use some way to encode the plane, direction.</p></li> <li><p>Use floating number. To count same number of points, we can sort (x, y, z) by using the following compare function: if (abs(A.x — B.x) > eps){return A.x < B.x} otherwise { if(abs(A.y-B.y)>eps){return A.y < B.y} otherwise return A.z < B.z}.</p></li> </ol></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/388\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 228 (Div. 1)</a> </span>\r\n </div>\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/389\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 228 (Div. 2)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-21-10684\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"21\",\n blogEntryId: \"10629\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-10684\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+45</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-10684\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/cgy4ever\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/cgy4ever\">\n cgy4ever\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Feb/03/2014 22:14\">10 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/10629#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/10629#comments\">\n 44\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"10700\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (39)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159842\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/YaleZ\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/24526/avatar/5b17db1affad55a5.jpg'/> </a>\n <div><a href=\"/profile/YaleZ\" title=\"Expert YaleZ\" class=\"rated-user user-blue\">YaleZ</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2014 22:38\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159842\" href=\"?#comment-159842\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"159842\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"159842\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"24526\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159842\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thank for timely editorial. I think Markdown is better when publish something on Github. Isn't it?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159842 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159842 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159842\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159846\" commentParentId=\"159842\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/cgy4ever\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2014 22:43\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159846\" href=\"?#comment-159846\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159842\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159846\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"11\"\r\n data-commentUserId=\"62\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+11</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159846\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Yes, I'm working on it. :)</p><p>The website seems to be not stable at this time. So I post them in other sites to ensure all people can see it.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159846 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159846 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159846\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159857\" commentParentId=\"159846\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Nodir.Daminov\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/71439/avatar/d6d2016f6dfe5ecd.jpg'/> </a>\n <div><a href=\"/profile/Nodir.Daminov\" title=\"Candidate Master Nodir.Daminov\" class=\"rated-user user-violet\">Nodir.Daminov</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2014 22:58\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159857\" href=\"?#comment-159857\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159846\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159857\" class=\"CommentVoteFrame\"\r\n class=\"too-negative-comment-vote\"\r\n data-commentRating=\"-35\"\r\n data-commentUserId=\"71439\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-35</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159857\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Maaan is it so hard to COPY ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159857 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159857 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159857\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159874\" commentParentId=\"159857\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/cgy4ever\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2014 23:19\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159874\" href=\"?#comment-159874\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159857\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159874\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"12\"\r\n data-commentUserId=\"62\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+12</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159874\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Sorry for the delay.</p><p>When I was submitting my post that contains the editorial, it always returns "Codeforces is now unavailable." so I just can't post it.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159874 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159874 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159874\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159859\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/BishalG\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/60637/avatar/d21ddf49bbd1630c.jpg'/> </a>\n <div><a href=\"/profile/BishalG\" title=\"Expert BishalG\" class=\"rated-user user-blue\">BishalG</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2014 22:58\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159859\" href=\"?#comment-159859\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159859\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"60637\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159859\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Nice problemSets @<a class=\"rated-user user-orange\" href=\"/profile/cgy4ever\" title=\"International Master cgy4ever\">cgy4ever</a> , although I misunderstood the problem-B <a href=\"/contest/389/problem/B\" title=\"Codeforces Round 228 (Div. 2)\">389B - Fox and Cross</a> upto 1 hrs :( </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159859 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159859 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159859\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159867\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Mr.ink\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Mr.ink\" title=\"Expert Mr.ink\" class=\"rated-user user-blue\">Mr.ink</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2014 23:07\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159867\" href=\"?#comment-159867\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159867\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"128876\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159867\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>due to my slow internet speed i can not see your editorial on github because my country internet has problem with https! </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159867 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159867 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159867\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159881\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Mr.ink\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Mr.ink\" title=\"Expert Mr.ink\" class=\"rated-user user-blue\">Mr.ink</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2014 23:38\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159881\" href=\"?#comment-159881\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159881\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"128876\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159881\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>does anyone have a better solution for div2 C problem?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159881 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159881 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159881\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159883\" commentParentId=\"159881\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/t_thirupathi\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/146179/avatar/98c28348196ce4ca.jpg'/> </a>\n <div><a href=\"/profile/t_thirupathi\" title=\"Specialist t_thirupathi\" class=\"rated-user user-cyan\">t_thirupathi</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2014 23:42\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159883\" href=\"?#comment-159883\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159881\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159883\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"146179\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159883\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Have a look at mine <a href=\"/contest/389/submission/5878414\" title=\"Submission 5878414 by t_thirupathi\">5878414</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159883 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159883 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159883\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159909\" commentParentId=\"159883\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/9charles\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/119814/avatar/653156a3153bc2dd.jpg'/> </a>\n <div><a href=\"/profile/9charles\" title=\"Expert 9charles\" class=\"rated-user user-blue\">9charles</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 06:46\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159909\" href=\"?#comment-159909\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159883\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159909\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"119814\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159909\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can you explain it?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159909 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159909 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159909\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159907\" commentParentId=\"159881\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/k790alex\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/119882/avatar/4baeddca65b2b958.jpg'/> </a>\n <div><a href=\"/profile/k790alex\" title=\"Specialist k790alex\" class=\"rated-user user-cyan\">k790alex</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 06:28\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159907\" href=\"?#comment-159907\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159881\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159907\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"119882\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159907\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I don't know if this is a better way but I didt in the contest.</p><p>Start making a pile with the low strength and while possible, look for a box that can support at least 1 box, then at least 2 boxes, 3, etc, repeat it while you have boxes.</p><p>My solution: <a href=\"/contest/389/submission/5879464\" title=\"Submission 5879464 by k790alex\">5879464</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159907 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159907 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159907\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159914\" commentParentId=\"159907\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/YaleZ\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/24526/avatar/5b17db1affad55a5.jpg'/> </a>\n <div><a href=\"/profile/YaleZ\" title=\"Expert YaleZ\" class=\"rated-user user-blue\">YaleZ</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 07:38\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159914\" href=\"?#comment-159914\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159907\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159914\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"24526\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159914\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Greedy is also a nice solution.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159914 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159914 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159914\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159932\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/worfzyq\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/157364/avatar/8f104a361ed91be8.jpg'/> </a>\n <div><a href=\"/profile/worfzyq\" title=\"Expert worfzyq\" class=\"rated-user user-blue\">worfzyq</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 09:52\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159932\" href=\"?#comment-159932\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159932\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"157364\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159932\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>388C — Fox and Card Game This problem is good magic</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159932 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159932 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159932\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159935\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/orchidmajumder\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/63603/avatar/f8db3747466a7168.jpg'/> </a>\n <div><a href=\"/profile/orchidmajumder\" title=\"Specialist orchidmajumder\" class=\"rated-user user-cyan\">orchidmajumder</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 10:07\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159935\" href=\"?#comment-159935\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"159935\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"159935\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"7\"\r\n data-commentUserId=\"63603\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+7</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159935\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>hii everyone,in Div II E,I can't understand why the optimal play for JIRO is to take the bottom most card from the same pile from where CIEL is picking?should not it try to pick the maximum value among all bottom most card at it's every move??</p><p>Please someone explain why the strategy presented in the editorial is optimal.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159935 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159935 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159935\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159948\" commentParentId=\"159935\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Zzyzx\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/86049/avatar/c698ee674460e7eb.jpg'/> </a>\n <div><a href=\"/profile/Zzyzx\" title=\"Expert Zzyzx\" class=\"rated-user user-blue\">Zzyzx</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 13:07\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159948\" href=\"?#comment-159948\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159935\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159948\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"86049\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159948\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Ok, I'm afraid I do not have a rigorous proof for this. I'll just explain to you why I think it is right.</p><p>First of all, we need to understand that both Ciel and Jiro are smart. Now, whenever it is Ciel's turn, he will pick the "best pile" and try to take everything from that pile and then move on to the next "best pile". Jiro knows that his friend Ciel is smart, so he will try to stop him from taking everything. This can be done only if he picks from the same pile that Ciel does.</p><p>But your question is — what if there is a different pile whose bottom-most card is much better than the bottom-most card of the pile from which Ciel is picking right?</p><p>My answer to this is that, this situation will never arise. Because if there is such a pile, then Ciel will try to take that card in the first place and therefore, Ciel will be picking from the same pile that Jiro will want to pick from.</p><p>Am I making sense? Or is there a flaw in my argument?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159948 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159948 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159948\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159952\" commentParentId=\"159948\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/orchidmajumder\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/63603/avatar/f8db3747466a7168.jpg'/> </a>\n <div><a href=\"/profile/orchidmajumder\" title=\"Specialist orchidmajumder\" class=\"rated-user user-cyan\">orchidmajumder</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 13:32\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159952\" href=\"?#comment-159952\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159948\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159952\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"63603\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159952\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Yes I'm also thinking along the same line.Both are playing optimally and if Ciel is chosing any pile then jiro knows that this pile has better cards in the botttom half.So he won't choose ciel to take the advantage and vice versa.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159952 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159952 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159952\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159944\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hzyfr\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/hzyfr\" title=\"Expert hzyfr\" class=\"rated-user user-blue\">hzyfr</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 12:27\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159944\" href=\"?#comment-159944\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159944\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"129936\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159944\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I have a different idea on D div1 <a href=\"/contest/388/problem/D\" title=\"Codeforces Round 228 (Div. 1)\">388D - Fox and Perfect Sets</a> but I failed on getting some relations in one step.</p><p>Let <em>M</em> be the maximum element in set <em>S</em> . Then if <em>S</em> is a perfect set, its elements should have all bits equals <em>0</em> on positions in <em>M's</em> binary representation(otherwise there must exist another element bigger than <em>M</em>). So let <em>cnt</em> = (number of 1's in binary repersentation of <em>M</em>), then the number of perfect sets which has <em>M</em> as its greatest element is determined by <em>cnt</em> . Well, this is the step I can't come up with a solution(actually the target is to find the number of perfect sets which has <code>2^cnt-1</code> as its greatest element).</p><p>Then the last step is simple. We can apply something like doubling algorithm on the problem.</p><p>We are asked to find the number of perfect sets with all the elements not greater than <em>N</em> . Let's suppose <em>N+1</em> is a power of 2 then its easy to calculate how many numbers not greater than <em>N</em> has <em>cnt</em> = 1,2,...m where m is the length of <em>N</em> in binary representation. That's just simple combinatoric number <em>C(n,i) (1<=i<=n)</em> . And if we have done the previous step, it's easy to get the result.</p><p>Then think about common cases of <em>N</em> . Let's take the highest bit of N and since all above bits are determined, the number of 1's will just add a constant value. So calculate this part and subtract that highest bit of <em>N</em> and do the same thing on remaining value of <em>N</em> , until <em>N=0</em> . At that time we will get the correct answer. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159944 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159944 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159944\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159945\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/rexdf\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/23738/avatar/797fa665fbe1ca78.jpg'/> </a>\n <div><a href=\"/profile/rexdf\" title=\"Specialist rexdf\" class=\"rated-user user-cyan\">rexdf</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 12:36\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159945\" href=\"?#comment-159945\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159945\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"23738\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159945\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>dp[1] = 1, dp[v] = sum{dp[t] | dist(1,t) = dist(1,v) — 1}, then dp[2] is our answer. What's v means? what's '|' means? What's dp[v] means?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159945 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159945 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159945\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159949\" commentParentId=\"159945\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/sancho\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/85894/avatar/e31a4b24327c1000.jpg'/> </a>\n <div><a href=\"/profile/sancho\" title=\"Candidate Master sancho\" class=\"rated-user user-violet\">sancho</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 13:10\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159949\" href=\"?#comment-159949\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159945\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159949\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"85894\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159949\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>v — vertex, answer for which we are getting at this moment, | — means "such as", dp[v] — number of ways from 1 vertex to this one</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159949 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159949 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159949\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159947\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lol12\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/lol12\" title=\"Specialist lol12\" class=\"rated-user user-cyan\">lol12</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 13:04\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159947\" href=\"?#comment-159947\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159947\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"10\"\r\n data-commentUserId=\"152356\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+10</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159947\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can someone please explain solution of Div2-D. Thanx</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159947 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159947 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159947\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"160020\" commentParentId=\"159947\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/YaleZ\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/24526/avatar/5b17db1affad55a5.jpg'/> </a>\n <div><a href=\"/profile/YaleZ\" title=\"Expert YaleZ\" class=\"rated-user user-blue\">YaleZ</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/05/2014 07:07\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-160020\" href=\"?#comment-160020\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159947\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"160020\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"9\"\r\n data-commentUserId=\"24526\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+9</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-160020\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>You can think about binnary. Such as (13)10=(1101)2=((1+(2+0)*2)+1)*2+1</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-160020 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-160020 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-160020\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"469976\" commentParentId=\"159947\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/roll_no_1\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/631859/avatar/36d157f91f64fe7f.jpg'/> </a>\n <div><a href=\"/profile/roll_no_1\" title=\"Master roll_no_1\" class=\"rated-user user-orange\">roll_no_1</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Nov/09/2018 17:27\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-469976\" href=\"?#comment-469976\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-159947\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"469976\" revisionCount=\"4\" revision=\"4\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">4</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"469976\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"631859\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-469976\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Here's my implementation of the editorialist's explanation of Div-2 D / Div-1 B: <a href=\"/contest/388/submission/45480077\" title=\"Submission 45480077 by roll_no_1\">45480077</a>. I implemented the layers as [1], [1, 1], [2, 1, 1], [4, 2, 1, 1] and so on.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-469976 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-469976 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-469976\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159967\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/BENYAM1N\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/84938/avatar/d2ae2657d8898e38.jpg'/> </a>\n <div><a href=\"/profile/BENYAM1N\" title=\"Master BENYAM1N\" class=\"rated-user user-orange\">BENYAM1N</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 15:51\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159967\" href=\"?#comment-159967\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159967\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"13\"\r\n data-commentUserId=\"84938\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+13</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159967\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Very good contest and nice editorial. Hope from now on I see more contests from you.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159967 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159967 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159967\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"159984\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/kojak_\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/57722/avatar/38990eea59bc188e.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/kojak_\" title=\"Newbie kojak_\" class=\"rated-user user-gray\">kojak_</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 18:34\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-159984\" href=\"?#comment-159984\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"159984\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"57722\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-159984\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Did anyone come up with a DP solution for Div.2 C/ Div.1 A?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-159984 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-159984 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-159984\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"160012\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/IgorKoval\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/51322/avatar/afc854fff49f072a.jpg'/> </a>\n <div><a href=\"/profile/IgorKoval\" title=\"Candidate Master IgorKoval\" class=\"rated-user user-violet\">IgorKoval</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2014 23:17\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-160012\" href=\"?#comment-160012\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"160012\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"11\"\r\n data-commentUserId=\"51322\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+11</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-160012\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Объясните, пожалуйста, разбор задачи "388D — Fox and Perfect Sets" на пальцах. Как-нибудь без Гаусса и базисов. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-160012 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-160012 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-160012\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"160016\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Mr.ink\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Mr.ink\" title=\"Expert Mr.ink\" class=\"rated-user user-blue\">Mr.ink</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/05/2014 01:08\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-160016\" href=\"?#comment-160016\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"160016\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"128876\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-160016\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>fox and card games is a great problem.thanks!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-160016 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-160016 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-160016\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"160037\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/yaswanth\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/yaswanth\" title=\"Specialist yaswanth\" class=\"rated-user user-cyan\">yaswanth</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/05/2014 18:38\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-160037\" href=\"?#comment-160037\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"160037\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"9\"\r\n data-commentUserId=\"96196\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+9</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-160037\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can anyone explain div2 C question? I did not understand the editorial.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-160037 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-160037 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-160037\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"160063\" commentParentId=\"160037\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/YaleZ\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/24526/avatar/5b17db1affad55a5.jpg'/> </a>\n <div><a href=\"/profile/YaleZ\" title=\"Expert YaleZ\" class=\"rated-user user-blue\">YaleZ</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/06/2014 05:46\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-160063\" href=\"?#comment-160063\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-160037\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"160063\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"24526\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-160063\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>s[i]>=i/k -> k*s[i]>=i There are i boxes' strength smaller than i-th box. So we need to check if the boxes before i-th can be held.</p><p>(I don't know whether I have understood correctly...)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-160063 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-160063 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-160063\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"160053\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/yada\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/142663/avatar/49901b54d1c5f019.jpg'/> </a>\n <div><a href=\"/profile/yada\" title=\"Candidate Master yada\" class=\"rated-user user-violet\">yada</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/05/2014 23:24\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-160053\" href=\"?#comment-160053\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"160053\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"142663\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-160053\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Great Problem! I really enjoy it.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-160053 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-160053 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-160053\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"364019\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lnzva\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/305672/avatar/cf6c09a214141751.jpg'/> </a>\n <div><a href=\"/profile/lnzva\" title=\"Expert lnzva\" class=\"rated-user user-blue\">lnzva</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/02/2017 22:06\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-364019\" href=\"?#comment-364019\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"364019\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"364019\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"305672\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-364019\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In 388C, I'm having a hard time understanding why Jiro's optimal strategy would be to pick the pile Ciel just picked. Why not pick a pile which has a better bottom part than the one Ciel is picking? According to some comments, Ciel would then pick from the second pile-what if another pile has a much better top part? Could someone please help? I saw this problem first 6 months ago, and I had a hard time understanding why this greedy is correct; I saw this problem again today and am having trouble with it again, with no progress.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-364019 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-364019 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-364019\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"647866\" commentParentId=\"364019\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/_wzx27\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1458283/avatar/7d77b62012ae2398.jpg'/> </a>\n <div><a href=\"/profile/_wzx27\" title=\"Candidate Master _wzx27\" class=\"rated-user user-violet\">_wzx27</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/22/2020 18:33\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-647866\" href=\"?#comment-647866\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-364019\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"647866\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1458283\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-647866\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Let's consider such a two-piles situation:</p><p><em>111100</em></p><p><em>001111</em></p><p>is better for Ciel.</p><p>"1" means this card is picked by Ciel,while "0" by Jiro.</p><p>We know that better for Ciel means worse for Jiro.</p><p>So if</p><p><em>111100</em></p><p><em>001111</em></p><p>is better than</p><p><em>111000</em></p><p><em>000111</em></p><p>for Ciel.</p><p>Then when Ciel picked the <strong>first three cards</strong> from <strong>pile 1</strong>,Jiro can just pick the <strong>last three cards</strong> from <strong>pile 1</strong> and finally lead to the result:</p><p><em>111000</em></p><p><em>000111</em></p><p>which is not better for Ciel.</p><p>Generally, if the final result is not balance(half from top and half from bottom) while balance is better than such result for Jiro, Jiro has the ability to adjust it to be balance.So do Ciel.</p><p>Therefore,it reaches balance.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-647866 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-647866 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-647866\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"407776\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/madhur4127\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/568692/avatar/c7d62cc23c758819.jpg'/> </a>\n <div><a href=\"/profile/madhur4127\" title=\"Specialist madhur4127\" class=\"rated-user user-cyan\">madhur4127</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/15/2018 13:06\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-407776\" href=\"?#comment-407776\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"407776\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"568692\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-407776\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>@<a class=\"rated-user user-red\" href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\">cgy4ever</a>, github link shows 404 error(Page not found). Kindly fix it.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-407776 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-407776 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-407776\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"416354\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/introverted\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/657339/avatar/7a6edb1ecc1d3e09.jpg'/> </a>\n <div><a href=\"/profile/introverted\" title=\"Expert introverted\" class=\"rated-user user-blue\">introverted</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/23/2018 11:48\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-416354\" href=\"?#comment-416354\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"416354\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"657339\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-416354\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I solved the DIV1B problem with simple recursion and Divide and Conquer.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-416354 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-416354 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-416354\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"427890\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Nuu\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/652228/avatar/d59867d6477379dc.jpg'/> </a>\n <div><a href=\"/profile/Nuu\" title=\"Candidate Master Nuu\" class=\"rated-user user-violet\">Nuu</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/01/2018 22:33\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-427890\" href=\"?#comment-427890\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"427890\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"652228\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-427890\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can anyone give me some examples of the similar problems to DivC?? I think this problem is very nice for train brain xD</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-427890 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-427890 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-427890\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"629609\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/The_Alchemist\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1275181/avatar/662970aa05d3dfc5.jpg'/> </a>\n <div><a href=\"/profile/The_Alchemist\" title=\"Expert The_Alchemist\" class=\"rated-user user-blue\">The_Alchemist</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/25/2020 21:47\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-629609\" href=\"?#comment-629609\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"629609\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1275181\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-629609\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I know I am very late but can someone pls explain to me div 2C/div1A. Thanks in advance... </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-629609 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-629609 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-629609\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"641010\" commentParentId=\"629609\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/kstheking\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1160931/avatar/e144fc7b0fdb90b1.jpg'/> </a>\n <div><a href=\"/profile/kstheking\" title=\"Pupil kstheking\" class=\"rated-user user-green\">kstheking</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/13/2020 14:47\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-641010\" href=\"?#comment-641010\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-629609\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"641010\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1160931\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-641010\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p><a href=\"https://codeforces.com/contest/388/submission/83605110\">https://codeforces.com/contest/388/submission/83605110</a> Here you go, if you don't get it feel free to ask</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-641010 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-641010 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-641010\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"644488\" commentParentId=\"641010\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/tanisha_\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/tanisha_\" title=\"Newbie tanisha_\" class=\"rated-user user-gray\">tanisha_</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/18/2020 15:26\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-644488\" href=\"?#comment-644488\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-641010\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"644488\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1500127\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-644488\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>is this any algorithm</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-644488 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-644488 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-644488\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"647627\" commentParentId=\"644488\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/kstheking\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1160931/avatar/e144fc7b0fdb90b1.jpg'/> </a>\n <div><a href=\"/profile/kstheking\" title=\"Pupil kstheking\" class=\"rated-user user-green\">kstheking</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/22/2020 08:40\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-647627\" href=\"?#comment-647627\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-644488\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"647627\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"647627\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1160931\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-647627\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Well you can call it a greedy algorithm, when we try to apply greedy by placing the heaviest block in bottom, a little problem occurs because of blocks of same strength for example in case of 10 2 2 1 1 0 0<br />If you try to apply greedy by choosing the strongest block<br />10 2 2 1<br />1 0<br />0<br />= 3 heaps<br />Which is wrong answer as sometimes we lose opportunity to create lesser heaps, as in this case if we use the second 2 to make another heap we can do better<br />10 2 1 0<br />2 1 0<br />= 2 heaps<br />So I apply greedy in the reverse direction by picking the smallest strength brick and placing below it the next smallest brick, this way the optimal number of heaps will be formed as in above example<br />choose 0, then you need >= 1, choose 1, then you need >= 2, choose 2, then you need >= 3 choose 10<br />repeat until you have chosen all the bricks<br />If you don't get anything, feel free to ask :) </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-647627 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-647627 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-647627\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"702677\" commentParentId=\"647627\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/breddreamer\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/853067/avatar/240684624b57996.jpg'/> </a>\n <div><a href=\"/profile/breddreamer\" title=\"Newbie breddreamer\" class=\"rated-user user-gray\">breddreamer</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/27/2020 13:01\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-702677\" href=\"?#comment-702677\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-647627\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"702677\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"853067\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-702677\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks, It helped me to understand your solution idea. And finally, I solved this one.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-702677 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-702677 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-702677\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"649225\" commentParentId=\"641010\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/The_Alchemist\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1275181/avatar/662970aa05d3dfc5.jpg'/> </a>\n <div><a href=\"/profile/The_Alchemist\" title=\"Expert The_Alchemist\" class=\"rated-user user-blue\">The_Alchemist</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/24/2020 12:04\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-649225\" href=\"?#comment-649225\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-641010\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"649225\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1275181\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-649225\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>thank you.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-649225 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-649225 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-649225\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n <br/>\r\n\r\n<div id=\"editBox-10700\" style=\"width:50em;display:none;\">\r\n <div class=\"previewBody\" style=\"border: 1px solid #d4d4d4; margin-bottom: 0.5em; padding: 0.25em; display:none;\"> </div>\r\n <div style=\"width: 1px\"> </div>\r\n <div class=\"commentLocale\" style=\"position: relative; top: 0.5em;left:4px;display: none;\">\r\n <input type=\"radio\" name=\"locale\" value=\"en\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In English</span>\r\n <input style=\"margin-left:1em\" type=\"radio\" name=\"locale\" value=\"ru\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In Russian</span>\r\n </div>\r\n <textarea data-drafts-id=\"CommentReplyFrame\" class=\"wysiwyg\" name=\"editContent\" rows=\"20\" style=\"width:99%;\"></textarea>\r\n <div class=\"error error__content\"></div>\r\n <div style=\"text-align:center;\">\r\n <input type=\"button\" name=\"preview\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Preview\"/>\r\n <input type=\"button\" name=\"save\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Save\"/>\r\n </div>\r\n</div>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n\r\nvar firstPreview10700 = true;\r\nvar lastPreviewContent10700 = '';\r\n\r\nif (!window.moveCommentRevision) {\r\n moveCommentRevision = function(e, dir) {\r\n var p = e.parent();\r\n var revisionCount = parseInt(p.attr(\"revisionCount\"));\r\n var revision = parseInt(p.attr(\"revision\"));\r\n var next = revision + dir;\r\n var commentId = p.attr(\"commentId\");\r\n if (next >= 1 && next <= revisionCount) {\r\n $.post(\r\n \"/data/comment-data\",\r\n {action: \"revision\", commentId: commentId, revision: next},\r\n function(json) {\r\n if (json.success == \"true\") {\r\n var parentDiv = e;\r\n\r\n while (parentDiv !== null && (parentDiv[0].nodeName.toLowerCase() !== \"td\" || !parentDiv.hasClass(\"right\"))) {\r\n parentDiv = parentDiv.parent();\r\n }\r\n\r\n if (parentDiv === null) {\r\n return;\r\n }\r\n\r\n parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\").html(json.content);\r\n Codeforces.setupSpoilers(parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\"));\r\n p.attr(\"revision\", next);\r\n p.find(\"span.revision\").text(next);\r\n if (next == 1) {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"visible\");\r\n }\r\n if (next == revisionCount) {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"visible\");\r\n }\r\n\r\n window.updateTypography();\r\n MathJax.Hub.Typeset();\r\n } else {\r\n alert(e.error);\r\n }\r\n },\r\n \"json\"\r\n );\r\n }\r\n };\r\n}\r\n\r\n$(\"div[commentableId=10700] a.leftRevision\").click(function () {\r\n window.moveCommentRevision($(this), -1);\r\n return false;\r\n});\r\n\r\n$(\"div[commentableId=10700] a.rightRevision\").click(function () {\r\n window.moveCommentRevision($(this), +1);\r\n return false;\r\n});\r\n\r\n\r\n\r\n });\n </script>\n\r\n\r\n <script src=\"//codeforces.org/s/81027/js/swfobject-2.2.min.js\" type=\"text/javascript\"></script>\n <script src=\"//codeforces.org/s/81027/js/ftaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n if (window.evercookie) {\n var ec = new evercookie({\n history: false,\n silverlight: false,\n baseurl: '',\n asseturi: '/assets',\n phpuri: '/2fdcd78',\n pngPath: '/eps',\n etagPath: '/ees',\n cachePath: '/ecs'\n });\n\n var randomNumber = function () {\n return Math.random().toString(36).substr(2);\n };\n\n var randomToken = function () {\n return (randomNumber() + randomNumber()).substring(0, 18);\n };\n\n window._ftaa = \"\";\n\n ec.get(\"70a7c28f3de\", function (value) {\n window._ftaa = value;\n if (!window._ftaa) {\n window._ftaa = randomToken();\n ec.set(\"70a7c28f3de\", window._ftaa);\n }\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n } else {\n window._ftaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\n <script src=\"//codeforces.org/s/81027/js/bfaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n var fpCallback = function() {\n Fingerprint2.get({}, function(components) {\n window._bfaa = Fingerprint2.x64hash128(components.map(function (pair) { return pair.value }).join(), 31);\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n };\n if (typeof Fingerprint2 !== 'undefined') {\n if (window.requestIdleCallback) {\n requestIdleCallback(fpCallback)\n } else {\n setTimeout(fpCallback, 500)\n }\n } else {\n window._bfaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"a.new-root-comment\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n\r\n $(\".comment-table .reply a\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".vote-for-comment\").mouseover(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").mouseout(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").click(function () {\r\n var vote = $(this);\r\n var commentId = $(this).parent().attr(\"commentid\");\r\n var commentRating = $(this).parent().attr(\"data-commentRating\");\r\n var direction = $(this).attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n $.post(\"/data/comment/vote\", {commentId: commentId, _tta: Codeforces.tta(), vote: direction, commentRating: commentRating}, function(data) {\r\n if (direction != 0 && !ownComment && data[\"success\"] == \"true\") {\r\n vote.parent().find(\".vote-for-comment\").attr(\"voteDirection\", 0);\r\n if (direction == 1)\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n else {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.closest(\".CommentVoteFrame\").find(\".ComplaintFrame\").css(\"display\", \"inline-block\");\r\n }\r\n vote.find(\"img\").attr(\"popacity\", \"1.0\");\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n vote.parent().find(\".commentRating\").html(data[\"commentRating\"]);\r\n }\r\n Codeforces.showMessage(data[\"message\"]);\r\n }, \"json\");\r\n return false;\r\n });\r\n\r\n $(\".negative-comment-vote\").closest(\".comment-table\").addClass(\"comment-bad\");\r\n\r\n $(\".troll-comment-vote\").closest(\".comment\").css(\"display\", \"none\");\r\n\r\n $(\".too-negative-comment-vote\").closest(\".comment-table\").each(function () {\r\n var e = $(this);\r\n e.addClass(\"comment-too-bad\");\r\n var commentId = e.attr(\"commentId\");\r\n $(\"<div class='bad-comment-replacement ttypography'>The comment is hidden because of too negative feedback, click <a href=# class=show-bad-comment-link>here</a> to view it</div>\").appendTo(\r\n e.find(\".right\")\r\n );\r\n e.find(\".comment-content\").hide();\r\n e.find(\".show-bad-comment-link\").click(function () {\r\n e.find(\".comment-content\").show();\r\n e.find(\".bad-comment-replacement\").hide();\r\n return false;\r\n });\r\n });\r\n });\n </script>\n </div>\r\n\r\n <style type=\"text/css\">\r\n .new-comments-box {\r\n padding: 0.5em;\r\n width: 22px;\r\n font-size: 1.3rem;\r\n font-weight: bold !important;\r\n\r\n position: fixed;\r\n top: 40%;\r\n right: 0;\r\n opacity: 0.2;\r\n color: white;\r\n text-align: center;\r\n\r\n border: 1px solid #222;\r\n background-color: #888 !important;\r\n border-radius: 3px;\r\n -moz-border-radius: 3px;\r\n -webkit-border-radius: 3px;\r\n }\r\n\r\n .new-comments-box:hover {\r\n opacity: 1;\r\n }\r\n\r\n .new-comments-box .dir:hover {\r\n background: #3B5998 !important;\r\n cursor: pointer;\r\n }\r\n </style>\r\n\r\n <div class=\"new-comments-box\" data-position=\"outside\" data-index=\"-1\" style=\"display: none;\">\r\n <div class=\"up dir\" title=\"Ctrl+Up\">↑<hr/>\r\n </div>\r\n <div class=\"info\" title=\"New comments\"></div>\r\n <div class=\"down dir\" title=\"Ctrl+Down\">\r\n <hr/>↓\r\n </div>\r\n </div>\r\n\r\n <script>\r\n $(\".show-archived-checkbox\").change(function () {\r\n const checked = $(this).is(\":checked\");\r\n $.post(\"/data/comment-data\", {action: \"setShowArchived\", checked}, function (json) {\r\n if (json[\"success\"] !== \"true\") {\r\n alert(json[\"error\"]);\r\n } else {\r\n if (checked) {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are now displayed\")\r\n } else {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are no longer displayed\")\r\n }\r\n }\r\n });\r\n return false;\r\n });\r\n\r\n function gotoComment(direction) {\r\n var box = $(\".new-comments-box\");\r\n var index = parseInt(box.attr(\"data-index\"));\r\n if (index == -1)\r\n index = 0;\r\n else\r\n index = Math.max(0, Math.min(parseInt(box.find(\".info\").text()) - 1, index + direction));\r\n box.attr(\"data-index\", index);\r\n var comment = $($(\".comment .highlight-blue[commentId]\").get(index));\r\n $('html, body').animate({\r\n 'scrollTop': Math.max(0, comment.offset().top - ($(window).height() - comment.height()) / 2)\r\n });\r\n return false;\r\n }\r\n\r\n $(\".new-comments-box .down\").click(function () {\r\n return gotoComment(1);\r\n });\r\n\r\n $(\".new-comments-box .up\").click(function () {\r\n return gotoComment(-1);\r\n });\r\n\r\n $(document).keydown(function (e) {\r\n var code = (e.keyCode ? e.keyCode : e.which);\r\n if (e.ctrlKey) {\r\n if (code == 38 || code == 40) {\r\n gotoComment(code - 39);\r\n }\r\n }\r\n });\r\n\r\n var newCommentCount = $(\".comment .highlight-blue[commentId]\").length;\r\n if (newCommentCount > 0) {\r\n $(\".new-comments-box .info\").text(newCommentCount);\r\n $(\".new-comments-box\").show();\r\n }\r\n\r\n $('table.comment-table').mouseenter(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").addClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n\r\n $('table.comment-table').mouseleave(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").removeClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n </script>\r\n\r\n\r\n\r\n <script>\r\n function adjustTopicComplainFrames() {\r\n let topicIds = [];\r\n\r\n $(\".has-topic-id\").each(function () {\r\n const $this = $(this);\r\n const topicId = $this.attr(\"topicId\");\r\n if (topicId) {\r\n topicIds.push(topicId);\r\n }\r\n });\r\n\r\n $.post(\"/data/topics\", {\r\n action: \"findComplainableTopicIds\",\r\n topicIds: topicIds.join(\",\")\r\n }, function (json) {\r\n if (json[\"success\"] === \"true\") {\r\n for (const topicId of json[\"complainableTopicIds\"].split(\",\")) {\r\n $(\".has-topic-id[topicId=\" + topicId + \"]\").each(function () {\r\n $(this).find(\".meta .ComplaintFrame\").css(\"display\", \"inline-block\");\r\n });\r\n }\r\n }\r\n }, \"json\");\r\n }\r\n\r\n $(function () {\r\n adjustTopicComplainFrames();\r\n })\r\n </script>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-10684\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 10684, _tta: Codeforces.tta(), topicRevisionId: 36670, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-10684\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 10684, _tta: Codeforces.tta(), topicRevisionId: 36670, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n </div>\r\n </div>\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 22:13:07</span> (h1).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/81027/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/81027/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/81027/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/81027/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-81027.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'812875a2ab4016f4',t:'MTY5NjcwNTk4Ny4yMjQwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"}}},{"rowIdx":1968,"cells":{"problem_id":{"kind":"string","value":"390A"},"contest":{"kind":"string","value":"390"},"problem":{"kind":"string","value":"A"},"lang":{"kind":"string","value":"en"},"problem_title":{"kind":"string","value":"A. Inna and Alarm Clock"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">A. Inna and Alarm Clock</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Inna loves sleeping very much, so she needs <span class=\"tex-span\"><i>n</i></span> alarm clocks in total to wake up. Let's suppose that Inna's room is a <span class=\"tex-span\">100 × 100</span> square with the lower left corner at point <span class=\"tex-span\">(0, 0)</span> and with the upper right corner at point <span class=\"tex-span\">(100, 100)</span>. Then the alarm clocks are points with integer coordinates in this square.</p><p>The morning has come. All <span class=\"tex-span\"><i>n</i></span> alarm clocks in Inna's room are ringing, so Inna wants to turn them off. For that Inna has come up with an amusing game:</p><ul> <li> First Inna chooses a type of segments that she will use throughout the game. The segments can be either vertical or horizontal. </li><li> Then Inna makes multiple moves. In a single move, Inna can paint a segment of any length on the plane, she chooses its type at the beginning of the game (either vertical or horizontal), then all alarm clocks that are on this segment switch off. The game ends when all the alarm clocks are switched off. </li></ul><p>Inna is very sleepy, so she wants to get through the alarm clocks as soon as possible. Help her, find the minimum number of moves in the game that she needs to turn off all the alarm clocks!</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line of the input contains integer <span class=\"tex-span\"><i>n</i></span> <span class=\"tex-span\">(1 ≤ <i>n</i> ≤ 10<sup class=\"upper-index\">5</sup>)</span> — the number of the alarm clocks. The next <span class=\"tex-span\"><i>n</i></span> lines describe the clocks: the <span class=\"tex-span\"><i>i</i></span>-th line contains two integers <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span>, <span class=\"tex-span\"><i>y</i><sub class=\"lower-index\"><i>i</i></sub></span> — the coordinates of the <span class=\"tex-span\"><i>i</i></span>-th alarm clock <span class=\"tex-span\">(0 ≤ <i>x</i><sub class=\"lower-index\"><i>i</i></sub>, <i>y</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 100)</span>.</p><p>Note that a single point in the room can contain any number of alarm clocks and the alarm clocks can lie on the sides of the square that represents the room.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>In a single line print a single integer — the minimum number of segments Inna will have to draw if she acts optimally.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>4<br/>0 0<br/>0 1<br/>0 2<br/>1 0<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>2<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>4<br/>0 0<br/>0 1<br/>1 0<br/>1 1<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>2<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>4<br/>1 1<br/>1 2<br/>2 3<br/>3 3<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>3<br/></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>In the first sample, Inna first chooses type \"vertical segments\", and then she makes segments with ends at : <span class=\"tex-span\">(0, 0)</span>, <span class=\"tex-span\">(0, 2)</span>; and, for example, <span class=\"tex-span\">(1, 0)</span>, <span class=\"tex-span\">(1, 1)</span>. If she paints horizontal segments, she will need at least 3 segments.</p><p>In the third sample it is important to note that Inna doesn't have the right to change the type of the segments during the game. That's why she will need 3 horizontal or 3 vertical segments to end the game.</p></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"af70441cc8ec8616981a48a45b0c56f5\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - A - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"d468883313d2f01f0365840b13075e5c5bb1675c\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - A - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/73366/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/73366/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/73366/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/73366/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/73366/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/73366/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/73366/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/73366/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/73366/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/73366/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/73366/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/73366/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/73366/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/73366/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/sidebar-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/a037fe51637846d9c7c725713cd840ea/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='af70441cc8ec8616981a48a45b0c56f5'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/73366/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/73366/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fcontest%2F390%2Fproblem%2FA%3Flocale%3Den\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"current\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='af70441cc8ec8616981a48a45b0c56f5'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:100%;\"><a style=\"color: black\" href=\"/contest/390\">Codeforces Round 229 (Div. 2)</a></th>\n </tr>\n <tr>\n <td class=\"left bottom\" colspan=\"1\"><span class=\"contest-state-phase\">Finished</span></td>\n </tr>\n </tbody>\n </table>\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Practice?\n <div class=\"top-links\">\n </div>\n </div>\n<div>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Want to solve the contest problems after the official contest ends? Just register for practice and you will be able to submit solutions.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"\" method=\"post\"><input type='hidden' name='csrf_token' value='af70441cc8ec8616981a48a45b0c56f5'/>\r\n <input type=\"hidden\" name=\"action\" value=\"registerForPractice\"/>\r\n <input type=\"submit\" name=\"submit\" value=\"Register for practice\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div> \r\n</div>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox ContestVirtualFrame borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Virtual participation <i class=\"sidebar-caption-icon las la-angle-down\"></i>\r\n\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\" \"\r\n\r\n data-page-url=\"/data/sidebarFrames\"\r\n\r\n>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests.\n\nIf you've seen these problems, a virtual contest is not for you - solve these problems in the archive.\n\nIf you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.\n\nNever use someone else's code, read the tutorials or communicate with other person during a virtual contest.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"/contest/390/virtual\" method=\"get\">\r\n <input type=\"submit\" name=\"submit\" value=\"Start virtual contest\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div>\r\n</div>\r\n <script>\r\n $(function () {\r\n $(\".ContestVirtualFrame .sidebar-caption-icon\").click(function() {\r\n $(this).toggleClass(\"la-angle-down la-angle-right\");\r\n const $target = $(this).parent().next();\r\n $target.toggle();\r\n const dataPageUrl = $target.attr(\"data-page-url\");\r\n const collapsed = $(this).hasClass(\"la-angle-right\");\r\n const params = {\r\n action: \"setCollapsed\",\r\n sidebarFrameSimpleClassName: \"ContestVirtualFrame\",\r\n collapsed\r\n };\r\n $.each($target[0].attributes, function(i, a) {\r\n const name = a.name;\r\n if (name.startsWith(\"data-extra-key-\")) {\r\n const key = a.value;\r\n const keyIndex = parseInt(name.substring(\"data-extra-key-\".length));\r\n const value = $target.attr(\"data-extra-value-\" + keyIndex);\r\n params[key] = value;\r\n }\r\n });\r\n $.post(dataPageUrl, params, function (result) {\r\n if (result[\"success\"] !== \"true\") {\r\n Codeforces.showMessage(\"Failed to save collapsed state.\");\r\n }\r\n }, \"json\");\r\n return false;\r\n });\r\n })\r\n </script>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Problem tags\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Implementation problems, programming technics, simulation\">\r\n implementation\r\n</span>\r\n </div>\n <div style=\"clear:both;text-align:right;font-size:1.1rem;\">\r\n <span title=\"Please login into the Codeforces\" class=\"notice\">No tag edit access</span>\r\n </div>\r\n</div>\r\n </div>\n\r\n<form id=\"addTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='af70441cc8ec8616981a48a45b0c56f5'/>\r\n <input name=\"action\" type=\"hidden\" value=\"addTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"6702\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<form id=\"removeTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='af70441cc8ec8616981a48a45b0c56f5'/>\r\n <input name=\"action\" type=\"hidden\" value=\"removeTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"6702\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<script type=\"text/javascript\">\r\n $(\".tag-box img\").click(function () {\r\n var tagName = $(this).attr(\"value\");\r\n Codeforces.confirm(\"Are you sure you want to remove this tag?\", function () {\r\n $(\"#removeTagForm input[name=tagName]\").val(tagName);\r\n $(\"#removeTagForm\").submit();\r\n }, function () {\r\n }, \"Yes\", \"No\");\r\n });\r\n\r\n $(\"#addTagLink\").click(function () {\r\n $(this).hide();\r\n $(\"#addTagLabel\").show();\r\n return false;\r\n });\r\n\r\n $(\"#addTagSelect\").change(function () {\r\n var tagName = $(this).val();\r\n if (tagName === \"\") {\r\n $(\"#addTagLabel\").hide();\r\n $(\"#addTagLink\").show();\r\n } else {\r\n $(\"#addTagForm input[name=tagName]\").val(tagName);\r\n $(\"#addTagForm\").submit();\r\n }\r\n });\r\n</script>\r\n\r\n<style type=\"text/css\">\r\n#new-resource-form tr td {\r\npadding-top: 0.5em;\r\n}\r\n#new-resource-form input:not([type=\"submit\"]) {\r\nfont-size: 0.8em;\r\n}\r\n#new-resource-form select {\r\nfont-size: 0.8em;\r\n}\r\n.new-resource-error {\r\nfont-size: 0.8em;\r\n}\r\n.resource-locale {\r\ncolor: #666;\r\nfont-family: Consolas, \"Andale Mono WT\", \"Andale Mono\", \"Lucida Console\", \"Lucida Sans Typewriter\", \"DejaVu Sans Mono\", \"Bitstream Vera Sans Mono\", \"Liberation Mono\", \"Nimbus Mono L\", Monaco, \"Courier New\", Courier, monospace;\r\n}\r\n</style>\r\n<div class=\"roundbox sidebox sidebar-menu borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Contest materials\n<div class=\"top-links\">\n</div>\n</div>\n<ul>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/64453\" title=\"Editorial (Unofficial)\" target=\"_blank\">Editorial (Unofficial) <span class=\"resource-locale\">(en)</span></a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"17239\" resourceName=\"Editorial (Unofficial)\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n</ul>\r\n</div></div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li class=\"current selectedLava\"><a\r\n href=\"/contest/390\">Problems</a></li>\r\n <li><a\r\n href=\"/contest/390/submit\">Submit Code</a></li>\r\n <li><a\r\n href=\"/contest/390/my\">My Submissions</a></li>\r\n <li><a\r\n href=\"/contest/390/status\">Status</a></li>\r\n <li><a\r\n href=\"/contest/390/hacks\">Hacks</a></li>\r\n <li><a\r\n href=\"/contest/390/room/1\">Room</a></li>\r\n <li><a\r\n href=\"/contest/390/standings\">Standings</a></li>\r\n <li><a\r\n href=\"/contest/390/customtest\">Custom Invocation</a></li>\r\n</ul>\r\n</div>\n\r\n <style>\r\n #facebox .content:has(.diff-popup) {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n }\r\n\r\n .testCaseMarker {\r\n position: absolute;\r\n font-weight: bold;\r\n font-size: 1rem;\r\n }\r\n\r\n .diff-popup {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n display: none;\r\n overflow: auto;\r\n }\r\n\r\n .input-output-copier {\r\n font-size: 1.2rem;\r\n float: right;\r\n color: #888 !important;\r\n cursor: pointer;\r\n border: 1px solid rgb(185, 185, 185);\r\n padding: 3px;\r\n margin: 1px;\r\n line-height: 1.1rem;\r\n text-transform: none;\r\n }\r\n\r\n .input-output-copier:hover {\r\n background-color: #def;\r\n }\r\n\r\n .test-explanation textarea {\r\n width: 100%;\r\n height: 1.5em;\r\n }\r\n\r\n .pending-submission-message {\r\n color: darkorange !important;\r\n }\r\n </style>\r\n <script>\r\n const OPENING_SPACE = String.fromCharCode(1001);\r\n const CLOSING_SPACE = String.fromCharCode(1002);\r\n\r\n const nodeToText = function (node, pre) {\r\n let result = [];\r\n\r\n if (node.tagName === \"SCRIPT\" || node.tagName === \"math\"\r\n || (node.classList && node.classList.contains(\"input-output-copier\")))\r\n return [];\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(OPENING_SPACE);\r\n }\r\n\r\n if (node.nodeType === Node.TEXT_NODE) {\r\n let s = node.textContent;\r\n if (!pre) {\r\n s = s.replace(/\\s+/g, \" \");\r\n }\r\n if (s.length > 0) {\r\n result.push(s);\r\n }\r\n }\r\n\r\n if (pre && node.tagName === \"BR\") {\r\n result.push(\"\\n\");\r\n }\r\n\r\n node.childNodes.forEach(function (child) {\r\n result.push(nodeToText(child, node.tagName === \"PRE\").join(\"\"));\r\n });\r\n\r\n if (node.tagName === \"DIV\"\r\n || node.tagName === \"P\"\r\n || node.tagName === \"PRE\"\r\n || node.tagName === \"UL\"\r\n || node.tagName === \"LI\"\r\n ) {\r\n result.push(\"\\n\");\r\n }\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(CLOSING_SPACE);\r\n }\r\n\r\n return result;\r\n }\r\n\r\n const isSpecial = function (c) {\r\n return c === ',' || c === '.' || c === ';' || c === ')' || c === ' ';\r\n }\r\n\r\n const convertStatementToText = function(statmentNode) {\r\n const text = nodeToText(statmentNode, false).join(\"\").replace(/ +/g, \" \").replace(/\\n\\n+/g, \"\\n\\n\");\r\n let result = [];\r\n for (let i = 0; i < text.length; i++) {\r\n const c = text.charAt(i);\r\n if (c === OPENING_SPACE) {\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"A\" data-uuid=\"ps_a9470242a6c191057f55fb386b01894ddf71ba00\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">A. Inna and Alarm Clock</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Inna loves sleeping very much, so she needs <span class=\"tex-span\"><i>n</i></span> alarm clocks in total to wake up. Let's suppose that Inna's room is a <span class=\"tex-span\">100 × 100</span> square with the lower left corner at point <span class=\"tex-span\">(0, 0)</span> and with the upper right corner at point <span class=\"tex-span\">(100, 100)</span>. Then the alarm clocks are points with integer coordinates in this square.</p><p>The morning has come. All <span class=\"tex-span\"><i>n</i></span> alarm clocks in Inna's room are ringing, so Inna wants to turn them off. For that Inna has come up with an amusing game:</p><ul> <li> First Inna chooses a type of segments that she will use throughout the game. The segments can be either vertical or horizontal. </li><li> Then Inna makes multiple moves. In a single move, Inna can paint a segment of any length on the plane, she chooses its type at the beginning of the game (either vertical or horizontal), then all alarm clocks that are on this segment switch off. The game ends when all the alarm clocks are switched off. </li></ul><p>Inna is very sleepy, so she wants to get through the alarm clocks as soon as possible. Help her, find the minimum number of moves in the game that she needs to turn off all the alarm clocks!</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line of the input contains integer <span class=\"tex-span\"><i>n</i></span> <span class=\"tex-span\">(1 ≤ <i>n</i> ≤ 10<sup class=\"upper-index\">5</sup>)</span> — the number of the alarm clocks. The next <span class=\"tex-span\"><i>n</i></span> lines describe the clocks: the <span class=\"tex-span\"><i>i</i></span>-th line contains two integers <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span>, <span class=\"tex-span\"><i>y</i><sub class=\"lower-index\"><i>i</i></sub></span> — the coordinates of the <span class=\"tex-span\"><i>i</i></span>-th alarm clock <span class=\"tex-span\">(0 ≤ <i>x</i><sub class=\"lower-index\"><i>i</i></sub>, <i>y</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 100)</span>.</p><p>Note that a single point in the room can contain any number of alarm clocks and the alarm clocks can lie on the sides of the square that represents the room.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>In a single line print a single integer — the minimum number of segments Inna will have to draw if she acts optimally.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>4<br />0 0<br />0 1<br />0 2<br />1 0<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>2<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>4<br />0 0<br />0 1<br />1 0<br />1 1<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>2<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>4<br />1 1<br />1 2<br />2 3<br />3 3<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>3<br /></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>In the first sample, Inna first chooses type "vertical segments", and then she makes segments with ends at : <span class=\"tex-span\">(0, 0)</span>, <span class=\"tex-span\">(0, 2)</span>; and, for example, <span class=\"tex-span\">(1, 0)</span>, <span class=\"tex-span\">(1, 1)</span>. If she paints horizontal segments, she will need at least 3 segments.</p><p>In the third sample it is important to note that Inna doesn't have the right to change the type of the segments during the game. That's why she will need 3 horizontal or 3 vertical segments to end the game.</p></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=A]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== statementText) {\r\n $problem.find(\".diff-notifier\").show();\r\n\r\n $problem.find(\".diff-notifier-close\").click(function() {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n $problem.find(\".diff-notifier\").hide();\r\n });\r\n\r\n $problem.find(\"a.view-changes\").click(function() {\r\n $.post(\"/data/diff\", {action: \"getDiff\", a: previousStatementText, b: statementText}, function (result) {\r\n if (result[\"success\"] === \"true\") {\r\n Codeforces.facebox(\".diff-popup\", \"//codeforces.org/s/73366\");\r\n $(\"#facebox .diff-popup\").html(result[\"diff\"]);\r\n }\r\n }, \"json\");\r\n });\r\n }\r\n } else {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n }\r\n });\r\n });\r\n </script>\r\n\r\n\r\n<script type=\"text/javascript\">\r\n $(document).ready(function () {\r\n window.changedTests = new Set();\r\n\r\n function endsWith(string, suffix) {\r\n return string.indexOf(suffix, string.length - suffix.length) !== -1;\r\n }\r\n\r\n const inputFileDiv = $(\"div.input-file\");\r\n const inputFile = inputFileDiv.text();\r\n const outputFileDiv = $(\"div.output-file\");\r\n const outputFile = outputFileDiv.text();\r\n\r\n\r\n if (!endsWith(inputFile, \"standard input\")\r\n && !endsWith(inputFile, \"standard input\")) {\r\n inputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n if (!endsWith(outputFile, \"standard output\")\r\n && !endsWith(outputFile, \"standard output\")) {\r\n outputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n const titleDiv = $(\"div.header div.title\");\r\n\r\n\r\n\r\n String.prototype.replaceAll = function (search, replace) {\r\n return this.split(search).join(replace);\r\n };\r\n\r\n $(\".sample-test .title\").each(function () {\r\n const preId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n const cpyId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n\r\n $(this).parent().find(\"pre\").attr(\"id\", preId);\r\n const $copy = $(\"<div title='Copy' data-clipboard-target='#\" + preId + \"' id='\" + cpyId + \"' class='input-output-copier'>Copy</div>\");\r\n $(this).append($copy);\r\n\r\n const clipboard = new Clipboard('#' + cpyId, {\r\n text: function (trigger) {\r\n const pre = document.querySelector('#' + preId);\r\n const lines = pre.querySelectorAll(\".test-example-line\");\r\n return Codeforces.filterClipboardText(pre.innerText, lines.length);\r\n }\r\n });\r\n\r\n const isInput = $(this).parent().hasClass(\"input\");\r\n\r\n clipboard.on('success', function (e) {\r\n if (isInput) {\r\n Codeforces.showMessage(\"The example input has been copied into the clipboard\");\r\n } else {\r\n Codeforces.showMessage(\"The example output has been copied into the clipboard\");\r\n }\r\n e.clearSelection();\r\n });\r\n });\r\n\r\n $(\".test-form-item input\").change(function () {\r\n addPendingSubmissionMessage($($(this).closest(\"form\")), \"You changed the answer, do not forget to submit it if you want to save the changes\");\r\n const index = $(this).closest(\".problemindexholder\").attr(\"problemindex\");\r\n let test = \"\";\r\n $(this).closest(\"form input\").each(function () {\r\n const test_ = $(this).attr(\"name\");\r\n if (test_ && test_.substring(0, 4) === \"test\") {\r\n test = test_;\r\n }\r\n });\r\n if (index.length > 0 && test.length > 0) {\r\n const indexTest = index + \"::\" + test;\r\n window.changedTests.add(indexTest);\r\n }\r\n });\r\n\r\n $(window).on('beforeunload', function () {\r\n if (window.changedTests.size > 0) {\r\n return 'Dialog text here';\r\n }\r\n });\r\n\r\n autosize($('.test-explanation textarea'));\r\n\r\n $(\".test-example-line\").hover(function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n let top = 1E20;\r\n let left = 1E20;\r\n let problem = $(this).closest(\".problemindexholder\");\r\n $(this).closest(\".input\").find(\".\" + clazz).css(\"background-color\", \"#FFFDE7\").each(function() {\r\n top = Math.min(top, $(this).offset().top);\r\n left = Math.min(left, $(this).offset().left);\r\n });\r\n let testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n if (testCaseMarker.length === 0) {\r\n const html = \"<div class=\\\"testCaseMarker testCaseMarker_\" + end + \" notice\\\"></div>\";\r\n problem.append($(html));\r\n testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n }\r\n if (testCaseMarker) {\r\n testCaseMarker.show()\r\n .offset({top, left: left - 20})\r\n .text(end);\r\n }\r\n }\r\n }\r\n });\r\n }, function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n $(\".\" + clazz).css(\"background-color\", \"\");\r\n $(this).closest(\".problemindexholder\").find(\".testCaseMarker_\" + end).hide();\r\n }\r\n }\r\n });\r\n });\r\n\r\n });\r\n</script>\r\n\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 05:38:42</span> (j3).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/73366/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/73366/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/73366/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/73366/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-73366.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'8122c4fd9c4d9d3a',t:'MTY5NjY0NjMyMi45NTAwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"},"long_tags":{"kind":"string","value":"[\"Implementation problems, programming technics, simulation\"]"},"short_tags":{"kind":"string","value":"[\"implementation\"]"},"tutorial_link":{"kind":"string","value":"https://codeforces.com/blog/entry/64453"},"tutorial_page":{"kind":"string","value":"\r\n\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"642864061f7f8f253cd15a412d138165\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"h1\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Codeforces Round #229 (Div. 2) Editorial [Unofficial] - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n \n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Codeforces Round #229 (Div. 2) Editorial [Unofficial] - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/81027/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/81027/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/81027/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/81027/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/81027/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/81027/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/81027/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/81027/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/81027/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/81027/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/81027/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/81027/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/81027/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/81027/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/573cedc6b04c15481941f418269f4057/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='642864061f7f8f253cd15a412d138165'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/81027/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fblog%2Fentry%2F64453\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='642864061f7f8f253cd15a412d138165'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Pay attention\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n <div style=\"text-align:center;border-bottom: 1px solid rgb(185, 185, 185);margin:0 -0.5em 0.5em -0.5em;padding: 0 1em 0.5em 1em;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 1, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:51:52</span><br/><a href=\"/contestRegistration/1876\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n <div style=\"text-align:center;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 2, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:51:52</span><br/><a href=\"/contestRegistration/1877\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='642864061f7f8f253cd15a412d138165'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n </label>\r\n </div>\r\n <div style=\"padding: 0 1em 1em 1em;text-align:right;\">\r\n <input style=\"height:1.65em;padding:0 0.75em;\" type=\"submit\" value=\"Find\"/>\r\n </div>\r\n </form>\r\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".handleBox\").autocomplete(\"/data/handles\", {\r\n delay: 200,\r\n width: 200,\r\n selectFirst: false,\r\n matchContains: true,\r\n minChars: 3\r\n });\r\n $(\".handleForm\").attr(\"autocomplete\", \"off\").submit(function () {\r\n var link = \"/profile/userHandle\".replace(\r\n \"userHandle\", $(this).find(\".handleBox\").val()\r\n );\r\n window.location = link;\r\n return false;\r\n });\r\n });\n </script>\n\r\n\r\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Recent actions\n <div class=\"top-links\">\n </div>\n </div>\n <div class=\"recent-actions\">\r\n <ul>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/121073\">Meta Hacker Cup 2023 Round 1</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/.Danet\" title=\"Expert .Danet\" class=\"rated-user user-blue\">.Danet</a> →\r\n <a href=\"/blog/entry/121172\">[TLE on pretest1]</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\" class=\"rated-user user-red\">Pyqe</a> →\r\n <a href=\"/blog/entry/121025\">Codeforces Round #902 (Div. 1, Div. 2, based on COMPFEST 15 — Final Round)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pranshu_Pandya\" title=\"Specialist Pranshu_Pandya\" class=\"rated-user user-cyan\">Pranshu_Pandya</a> →\r\n <a href=\"/blog/entry/121171\">An Interesting Tree Problem</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/sszcdjr\" title=\"Master sszcdjr\" class=\"rated-user user-orange\">sszcdjr</a> →\r\n <a href=\"/blog/entry/119859\">Codeforces Round 896 (Div. 1, Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/119880\">It's Happening! Meta Hacker Cup 2023 Schedule</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/DaviddeGea1\" title=\"Expert DaviddeGea1\" class=\"rated-user user-blue\">DaviddeGea1</a> →\r\n <a href=\"/blog/entry/70917\">Number of ways of dividing an array into 2 parts such that sum of each part is > k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bekh\" title=\"Master Bekh\" class=\"rated-user user-orange\">Bekh</a> →\r\n <a href=\"/blog/entry/74245\">Questions and doubts regarding Aliens DP trick</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a> →\r\n <a href=\"/blog/entry/8192\">Codeforces Round #190 — Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/hocky\" title=\"Candidate Master hocky\" class=\"rated-user user-violet\">hocky</a> →\r\n <a href=\"/blog/entry/95323\">FBHC wuining uw Day? Incwease uw stacc size! (ㅅ´ ˘ `)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/liouzhou_101\" title=\"International Master liouzhou_101\" class=\"rated-user user-orange\">liouzhou_101</a> →\r\n <a href=\"/blog/entry/87598\">Editorial of Codeforces Round #700</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/yeon_gist\" title=\"Newbie yeon_gist\" class=\"rated-user user-gray\">yeon_gist</a> →\r\n <a href=\"/blog/entry/121170\">plusMinusPermutation computing error</a>\r\n <img alt=\"Text created or updated\" title=\"Text created or updated\" src=\"//codeforces.org/s/81027/images/icons/x-update-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/altforminuscontribution\" title=\"Newbie altforminuscontribution\" class=\"rated-user user-gray\">altforminuscontribution</a> →\r\n <a href=\"/blog/entry/121162\">My screen get unexpectedly big, what should I do</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/atcoder_official\" title=\"Unrated, atcoder_official\" class=\"rated-user user-black\">atcoder_official</a> →\r\n <a href=\"/blog/entry/121120\">We will hold UNIQUE VISION Programming Contest 2023 Autumn(AtCoder Beginner Contest 323)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/YouStill_DontKnowMeYet\" title=\"Candidate Master YouStill_DontKnowMeYet\" class=\"rated-user user-violet\">YouStill_DontKnowMeYet</a> →\r\n <a href=\"/blog/entry/117659\">[GYM] Al-Baath Collegiate Programming Contest 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/ankancool\" title=\"Expert ankancool\" class=\"rated-user user-blue\">ankancool</a> →\r\n <a href=\"/blog/entry/121136\">Invitation to AstroByte 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/GeZhiyuan\" title=\"Grandmaster GeZhiyuan\" class=\"rated-user user-red\">GeZhiyuan</a> →\r\n <a href=\"/blog/entry/120943\">Codeforces Round 901 (Div. 1, Div. 2) Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a> →\r\n <a href=\"/blog/entry/120772\">PSA: Increase your stack size before the Meta Hacker Cup, here's how</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/dino_merlin\" title=\"Expert dino_merlin\" class=\"rated-user user-blue\">dino_merlin</a> →\r\n <a href=\"/blog/entry/121145\">Intuitive approach for CEOI Kangaroo?</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/icecuber\" title=\"Grandmaster icecuber\" class=\"rated-user user-red\">icecuber</a> →\r\n <a href=\"/blog/entry/70018\">CSES DP section editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bn00b\" title=\"Newbie Bn00b\" class=\"rated-user user-gray\">Bn00b</a> →\r\n <a href=\"/blog/entry/98820\">[FEATURE REQUEST : ATCODER] TOPICS TAGS AND SORTING BY SOLVE COUNT</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a> →\r\n <a href=\"/blog/entry/121163\">AtCoder Regular Contest 166 Announcement</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/windva\" title=\"Grandmaster windva\" class=\"rated-user user-red\">windva</a> →\r\n <a href=\"/blog/entry/120644\">Codeforces Round 899 (Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Misa-Misa\" title=\"Expert Misa-Misa\" class=\"rated-user user-blue\">Misa-Misa</a> →\r\n <a href=\"/blog/entry/121157\">Someone please help me understand this.</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/shivam565\" title=\"Specialist shivam565\" class=\"rated-user user-cyan\">shivam565</a> →\r\n <a href=\"/blog/entry/108348\">Total number of subarrays with sum atmost k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n </ul>\r\n </div>\r\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/recent-actions\">Detailed →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n</div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li><a\r\n href=\"/profile/AkiLotus\">AkiLotus</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/AkiLotus\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/AkiLotus\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/AkiLotus\">Submissions</a></li>\r\n <li><a\r\n href=\"/groups/with/AkiLotus\">Groups</a></li>\r\n <li><a\r\n href=\"/contests/with/AkiLotus\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/AkiLotus\">Problemsetting</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/AkiLotus\" style=\"text-decoration:none;color:black !important;\">AkiLotus's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"64858\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/64453\"> <p>Codeforces Round #229 (Div. 2) Editorial [Unofficial]</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/AkiLotus\" title=\"Master AkiLotus\" class=\"rated-user user-orange\">AkiLotus</a>,\r\n <a href=\"/topic/64858/en4\">history</a>,\r\n <span class=\"format-humantime\" title=\"Jan/11/2019 15:40\">5 years ago</span>,\r\n \r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p><em>Since the original data has been lost during the dark days of Codeforces, no version of the editorial has been re-released, and I feel the round itself is quite educational, so I decided to give a try.</em></p><h2><a href=\"/contest/390/problem/A\" title=\"Codeforces Round 229 (Div. 2)\">390A - Инна и будильники</a></h2> <div class=\"spoiler\"><b class=\"spoiler-title\">Approach</b><div class=\"spoiler-content\" style=\"display: none;\"><p>The criterion shows that we can only use either vertical segments or horizontal segments.<br />Since there is no limit on the segments' length, we can see that it's always optimal to use a segment with infinite length (or may be known as a line).</p><p>We can see that the vertical line <span class=\"tex-span\"><i>x</i> = <i>a</i></span> will span through every alarm clocks standing at positions with x-coordinate being equal to <span class=\"tex-span\"><i>a</i></span>. In a similar manner, the horizontal line <span class=\"tex-span\"><i>y</i> = <i>b</i></span> will span through every alarm clocks standing at positions with y-coordinate being equal to <span class=\"tex-span\"><i>b</i></span>.</p><p>So, if we use vertical lines, the number of segments used will be the number of distinct values of x-coordinates found in the data. Similarly, the number of horizontal segments used will be the number of distinct values of y-coordinates found.</p><p>The process can be implemented by a counting array, or a map.</p><p>Time complexity: <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/e98e669660e295d23c96117b197140d3a3709707.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> for regular arrays, or <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/df2dace9ef526732e09735cc52a919faad47f167.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> for maps.</p></div></div> <div class=\"spoiler\"><b class=\"spoiler-title\">Solution 1 (Map)</b><div class=\"spoiler-content\" style=\"display: none;\"><p>Submission link: <a href=\"/contest/390/submission/48214007\" title=\"Посылка 48214007 от AkiLotus\">48214007</a></p> <div class=\"spoiler\"><b class=\"spoiler-title\">Source code in plain text</b><div class=\"spoiler-content\" style=\"display: none;\"><pre><code>#pragma GCC optimize("Ofast")\n\n#include <bits/stdc++.h>\nusing namespace std;\n\n#define endl '\\n'\nmt19937 rng32(chrono::steady_clock::now().time_since_epoch().count());\nmt19937_64 rng64(chrono::steady_clock::now().time_since_epoch().count());\n\nint main(int argc, char* argv[]) {\n\tios_base::sync_with_stdio(0); cin.tie(NULL);\n\t\n\tint n; cin >> n;\n\t\n\tmap<int, int> cntx, cnty;\n\t\n\twhile (n--) {\n\t\tint x, y;\n\t\tcin >> x >> y;\n\t\tcntx[x]++; cnty[y]++;\n\t}\n\t\n\tcout << min(cntx.size(), cnty.size()) << endl;\n\t\n\treturn 0;\n}\n</code></pre></div></div></div></div> <div class=\"spoiler\"><b class=\"spoiler-title\">Solution 2 (Array)</b><div class=\"spoiler-content\" style=\"display: none;\"><p>Submission link: <a href=\"/contest/390/submission/48213984\" title=\"Посылка 48213984 от AkiLotus\">48213984</a></p> <div class=\"spoiler\"><b class=\"spoiler-title\">Source code in plain text</b><div class=\"spoiler-content\" style=\"display: none;\"><pre><code>#pragma GCC optimize("Ofast")\n\n#include <bits/stdc++.h>\nusing namespace std;\n\n#define endl '\\n'\nmt19937 rng32(chrono::steady_clock::now().time_since_epoch().count());\nmt19937_64 rng64(chrono::steady_clock::now().time_since_epoch().count());\n\nint main(int argc, char* argv[]) {\n\tios_base::sync_with_stdio(0); cin.tie(NULL);\n\t\n\tint n; cin >> n;\n\t\n\tvector<int> cntx(101, 0);\n\tvector<int> cnty(101, 0);\n\t\n\twhile (n--) {\n\t\tint x, y;\n\t\tcin >> x >> y;\n\t\tcntx[x]++; cnty[y]++;\n\t}\n\t\n\tint distinctx = 0, distincty = 0;\n\tfor (int i=0; i<101; i++) {\n\t distinctx += (cntx[i] > 0);\n\t distincty += (cnty[i] > 0);\n\t}\n\t\n\tcout << min(distinctx, distincty) << endl;\n\t\n\treturn 0;\n}\n</code></pre></div></div></div></div><h2><a href=\"/contest/390/problem/B\" title=\"Codeforces Round 229 (Div. 2)\">390B - Инна, Дима и песня</a></h2> <div class=\"spoiler\"><b class=\"spoiler-title\">Approach</b><div class=\"spoiler-content\" style=\"display: none;\"><p>From the constraints given, for the <span class=\"tex-span\"><i>i</i></span>-th song, provided there exists corresponding <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span> and <span class=\"tex-span\"><i>y</i><sub class=\"lower-index\"><i>i</i></sub></span> values, then the following inequality must hold: <span class=\"tex-span\">2 ≤ <i>x</i><sub class=\"lower-index\"><i>i</i></sub> + <i>y</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 2·<i>a</i><sub class=\"lower-index\"><i>i</i></sub></span>.<br />Thus, if any <span class=\"tex-span\"><i>b</i><sub class=\"lower-index\"><i>i</i></sub></span> is either lower than <span class=\"tex-span\">2</span> or higher than <span class=\"tex-span\">2·<i>a</i><sub class=\"lower-index\"><i>i</i></sub></span>, then no <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span> and <span class=\"tex-span\"><i>y</i><sub class=\"lower-index\"><i>i</i></sub></span> can be found, thus, Sereja's joy will surely decrease by <span class=\"tex-span\">1</span>.</p><p>Amongst all pairs of <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/cb276cd4dc36f23b69b51abe41e17841282ed42c.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> that <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub> + <i>y</i><sub class=\"lower-index\"><i>i</i></sub> = <i>b</i><sub class=\"lower-index\"><i>i</i></sub></span>, the pair with the highest value of <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub>·<i>y</i><sub class=\"lower-index\"><i>i</i></sub></span> will be one with the equal value of <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub> = <i>y</i><sub class=\"lower-index\"><i>i</i></sub></span> (this can be proven by the famous AM-GM inequality).<br />Thus, if <span class=\"tex-span\"><i>b</i><sub class=\"lower-index\"><i>i</i></sub></span> is divisible by <span class=\"tex-span\">2</span>, we can easily pick <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/4ebbc716337dc5b987bc678f95685e3b6e874bfa.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />.<br />Also, from this, we can see (either intuitively or with static proofs) that the lower the difference between <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span> and <span class=\"tex-span\"><i>y</i><sub class=\"lower-index\"><i>i</i></sub></span> is, the higher the value <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub>·<i>y</i><sub class=\"lower-index\"><i>i</i></sub></span> will be. Thus, in case <span class=\"tex-span\"><i>b</i><sub class=\"lower-index\"><i>i</i></sub></span> being odd, the most optimal pair will be <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/4bc158af48fdad3d0dba7ead977ad08c6efd4343.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> or <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/443272cf5829fac4b5f9b1d92d3319449b0a967a.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> (the order doesn't matter here).</p><p>Time complexity: <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/e50d121c611e249696d85ac98167ee3dfa4ba3f3.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />.</p></div></div> <div class=\"spoiler\"><b class=\"spoiler-title\">Solution</b><div class=\"spoiler-content\" style=\"display: none;\"><p>Submission link: <a href=\"/contest/390/submission/48212208\" title=\"Посылка 48212208 от AkiLotus\">48212208</a></p> <div class=\"spoiler\"><b class=\"spoiler-title\">Source code in plain text</b><div class=\"spoiler-content\" style=\"display: none;\"><pre><code>#pragma GCC optimize("Ofast")\n\n#include <bits/stdc++.h>\nusing namespace std;\n\n#define endl '\\n'\nmt19937 rng32(chrono::steady_clock::now().time_since_epoch().count());\nmt19937_64 rng64(chrono::steady_clock::now().time_since_epoch().count());\n\nint main(int argc, char* argv[]) {\n\tios_base::sync_with_stdio(0); cin.tie(NULL);\n\t\n\tint n; cin >> n;\n\t\n\tvector<int> a(n), b(n);\n\tfor (auto &z: a) cin >> z;\n\tfor (auto &z: b) cin >> z;\n\t\n\tlong long Joy = 0;\n\tfor (int i=0; i<n; i++) {\n\t\tif (b[i] < 2 || b[i] > a[i] * 2) {Joy--; continue;}\n\t\tint x = b[i] / 2, y = b[i] - x;\n\t\tJoy += 1LL * x * y;\n\t}\n\tcout << Joy << endl;\n\t\n\treturn 0;\n}\n</code></pre></div></div></div></div><h2><a href=\"/contest/390/problem/C\" title=\"Codeforces Round 229 (Div. 2)\">390C - Инна и коробки с конфетами</a></h2> <div class=\"spoiler\"><b class=\"spoiler-title\">Approach</b><div class=\"spoiler-content\" style=\"display: none;\"><p>The query content looks pretty confusing at first, to be honest.<br />Since <span class=\"tex-span\"><i>k</i></span> is static throughout a scenario, we can group the boxes into <span class=\"tex-span\"><i>k</i></span> groups, the <span class=\"tex-span\"><i>z</i></span>-th box (in this editorial let's assume that the indices of the boxes start from <span class=\"tex-span\">0</span>) falls into group number <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/78bea9063020ea155fff32a481842014c32d98ba.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />.</p><p>Then, each query can be simplified as this: "Is that true that among the boxes with numbers from <span class=\"tex-span\"><i>l</i><sub class=\"lower-index\"><i>i</i></sub></span> to <span class=\"tex-span\"><i>r</i><sub class=\"lower-index\"><i>i</i></sub></span>, inclusive, the candies lie <strong>only</strong> in boxes of group <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/d252f9b61b64c0b830c9c0c1c3cda0fca9d00085.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />?</p><p>To make sure the answer for a query being "Yes", Dima has to remove candies from all candied-box in all groups other than <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/d252f9b61b64c0b830c9c0c1c3cda0fca9d00085.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />, while in that exact group, fill every empty box with a candy. Obviously, we'll consider boxes with indices between <span class=\"tex-span\"><i>l</i><sub class=\"lower-index\"><i>i</i></sub></span> and <span class=\"tex-span\"><i>r</i><sub class=\"lower-index\"><i>i</i></sub></span> inclusively only.</p><p>We can make <span class=\"tex-span\"><i>k</i></span> lists, the <span class=\"tex-span\"><i>t</i></span>-th (<span class=\"tex-span\">0</span>-indexed) list stores the indices of candied boxes in group <span class=\"tex-span\"><i>t</i></span>.</p><p>We'll process with each query as the following:</p> <ul> <li>Obviously, given from the criteria, each range will consist of exactly <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/830bdc9804371cb3a60ae9359bb9fe58149ae26d.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> boxes per each group. Let's denote <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/0220b561b0de8bb761315bed9f765526b1a82a12.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />.</li> <li>Traverse all groups, for the <span class=\"tex-span\"><i>t</i></span>-th group (again, <span class=\"tex-span\">0</span>-indexed), let's denote <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>t</i></sub></span> as the number of candied boxes of group <span class=\"tex-span\"><i>t</i></span> in the given range. This value can be calculated quickly through binary searching the constructed lists above.</li> <li>If group <span class=\"tex-span\"><i>t</i></span> is not the group being demanded to have candies (group <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/d252f9b61b64c0b830c9c0c1c3cda0fca9d00085.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />), we'll need to perform <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>t</i></sub></span> actions (removing candies). Otherwise, we'll need to perform <span class=\"tex-span\"><i>A</i> - <i>x</i><sub class=\"lower-index\"><i>t</i></sub></span> actions (adding candies to empty boxes).</li> </ul><p>Time complexity: <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/83fab29132fa3970fad25e1e222dfe177167bae6.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />.</p></div></div> <div class=\"spoiler\"><b class=\"spoiler-title\">Solution</b><div class=\"spoiler-content\" style=\"display: none;\"><p>Submission link: <a href=\"/contest/390/submission/48213932\" title=\"Посылка 48213932 от AkiLotus\">48213932</a></p> <div class=\"spoiler\"><b class=\"spoiler-title\">Source code in plain text</b><div class=\"spoiler-content\" style=\"display: none;\"><pre><code>#pragma GCC optimize("Ofast")\n\n#include <bits/stdc++.h>\nusing namespace std;\n\n#define endl '\\n'\nmt19937 rng32(chrono::steady_clock::now().time_since_epoch().count());\nmt19937_64 rng64(chrono::steady_clock::now().time_since_epoch().count());\n\nint main(int argc, char* argv[]) {\n\tios_base::sync_with_stdio(0); cin.tie(NULL);\n\t\n\tint n, k, w; string s;\n\tcin >> n >> k >> w >> s;\n\t\n\tvector< vector<int> > CandyGrp(k);\n\t\n\tfor (int i=0; i<n; i++) {\n\t if (s[i] == '0') continue;\n\t CandyGrp[i % k].push_back(i);\n\t}\n\t\n\twhile (w--) {\n\t int l, r;\n\t\tcin >> l >> r; l--; r--;\n\t\t\n\t\tint res = 0;\n\t\tint demandedGroup = (l + k - 1) % k;\n\t\tint BoxesPerGroup = (r - l + 1) / k;\n\t\t\n\t\tfor (int id=0; id<k; id++) {\n\t\t \n\t\t\tint x = lower_bound(CandyGrp[id].begin(), CandyGrp[id].end(), l) - CandyGrp[id].begin();\n\t\t\tint y = upper_bound(CandyGrp[id].begin(), CandyGrp[id].end(), r) - CandyGrp[id].begin();\n\t\t\t\n\t\t\tif (id == demandedGroup) {\n\t\t\t res += (BoxesPerGroup - (y - x));\n\t\t\t}\n\t\t\telse res += (y - x);\n\t\t}\n\t\t\n\t\tcout << res << endl;\n\t}\n\t\n\treturn 0;\n}\n</code></pre></div></div></div></div><h2><a href=\"/contest/390/problem/D\" title=\"Codeforces Round 229 (Div. 2)\">390D - Инна и матрица конфет</a></h2> <div class=\"spoiler\"><b class=\"spoiler-title\">Approach</b><div class=\"spoiler-content\" style=\"display: none;\"><p>We can see that the most optimal placement will be choosing <span class=\"tex-span\"><i>k</i></span> cells being nearest to cell <span class=\"tex-span\">(1, 1)</span> (yup, including <span class=\"tex-span\">(1, 1)</span> itself).<br />To find these <span class=\"tex-span\"><i>k</i></span> points, we can simply do a BFS starting from <span class=\"tex-span\">(1, 1)</span>, with traceback feature to construct the paths to get to those cells.<br />However, keep in mind that any cell being candied will later on become obstacles for the following paths. Thus, to avoid blocking yourself, you should transfer candies to the farthest cells first, then getting closer. Thus, cell <span class=\"tex-span\">(1, 1)</span> will be the last one being filled with candy.</p><p>Time complexity: <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/464cbb240e8ae8db0420805250b0ac00f29c8f7b.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> or <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/be7d2fc31b8207bf6178bb14a23b362773fd4c75.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />, based on implementation (I myself did <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/be7d2fc31b8207bf6178bb14a23b362773fd4c75.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />, since the difference isn't too much).</p></div></div> <div class=\"spoiler\"><b class=\"spoiler-title\">Solution</b><div class=\"spoiler-content\" style=\"display: none;\"><p>Submission link: <a href=\"/contest/390/submission/48213856\" title=\"Посылка 48213856 от AkiLotus\">48213856</a></p> <div class=\"spoiler\"><b class=\"spoiler-title\">Source code in plain text</b><div class=\"spoiler-content\" style=\"display: none;\"><pre><code>#pragma GCC optimize("Ofast")\n\n#include <bits/stdc++.h>\nusing namespace std;\n\n#define endl '\\n'\nmt19937 rng32(chrono::steady_clock::now().time_since_epoch().count());\nmt19937_64 rng64(chrono::steady_clock::now().time_since_epoch().count());\n\nint dx[] = {-1, +0, +0, +1};\nint dy[] = {+0, -1, +1, +0};\npair<int, int> Default = {-1, -1};\n\nint main(int argc, char* argv[]) {\n\tios_base::sync_with_stdio(0); cin.tie(NULL);\n\t\n\tint n, m, k; cin >> n >> m >> k;\n\t\n\tvector<vector<int>> Dist(n+2, vector<int>(m+2, 4444));\n\tvector<vector<pair<int, int>>> Last(n+2, vector<pair<int, int>>(m+2, Default));\n \n\tstack<pair<int, int>> Cells;\n\tint cost = 0;\n\t\n\tqueue<pair<int, int>> Q;\n\tQ.push({1, 1}); Dist[1][1] = 1;\n\t\n\twhile (!Q.empty() && Cells.size() < k) {\n\t\tpair<int, int> C = Q.front(); Q.pop();\n\t\tCells.push(C); int x = C.first, y = C.second;\n\t\t\n\t\tcost += Dist[x][y];\n\t\t\n\t\tfor (int dir=0; dir<4; dir++) {\n\t\t\tif (x + dx[dir] < 1 || x + dx[dir] > n) continue;\n\t\t\tif (y + dy[dir] < 1 || y + dy[dir] > m) continue;\n\t\t\t\n\t\t\tif (Dist[x+dx[dir]][y+dy[dir]] != 4444) continue;\n\t\t\t\n\t\t\tDist[x+dx[dir]][y+dy[dir]] = Dist[x][y] + 1;\n\t\t\tQ.push({x + dx[dir], y + dy[dir]});\n\t\t\tLast[x+dx[dir]][y+dy[dir]] = C;\n\t\t}\n\t}\n\t\n\tcout << cost << endl;\n\t\n\twhile (!Cells.empty()) {\n\t\tint x = Cells.top().first, y = Cells.top().second; Cells.pop();\n\t\tstack<pair<int, int>> Traceback;\n\t\t\n\t\twhile (x != -1 && y != -1) {\n\t\t\tTraceback.push({x, y});\n\t\t\tpair<int, int> NextCell = Last[x][y];\n\t\t\tx = NextCell.first; y = NextCell.second;\n\t\t}\n\t\t\n\t\twhile (!Traceback.empty()) {\n\t\t\tpair<int, int> CurCell = Traceback.top();\n\t\t\tTraceback.pop();\n\t\t\tcout << "(" << CurCell.first << ", " << CurCell.second << ") ";\n\t\t}\n\t\tcout << endl;\n\t}\n\t\n\treturn 0;\n}\n</code></pre></div></div></div></div><h2><a href=\"/contest/390/problem/E\" title=\"Codeforces Round 229 (Div. 2)\">390E - Инна и большая матрица конфет</a></h2> <div class=\"spoiler\"><b class=\"spoiler-title\">Approach</b><div class=\"spoiler-content\" style=\"display: none;\"><p>Let's denote <span class=\"tex-span\"><i>A</i></span> as the total number of candies on the board, <span class=\"tex-span\"><i>R</i><sub class=\"lower-index\"><i>i</i></sub></span> as the total number of candies on the <span class=\"tex-span\"><i>i</i></span>-th row (<span class=\"tex-span\">1 ≤ <i>i</i> ≤ <i>n</i></span>), <span class=\"tex-span\"><i>C</i><sub class=\"lower-index\"><i>j</i></sub></span> as the total number of candies on the <span class=\"tex-span\"><i>j</i></span>-th column (<span class=\"tex-span\">1 ≤ <i>j</i> ≤ <i>m</i></span>).</p><p>Also, let's denote <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/b38d7b9a33912f8ddf2960acee5927b6bfd14cb9.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> and <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/01d697cc3de45d71c1ae7efa08207ea0fbe4c73b.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />.</p><p>Let's considered the 2nd type of query first. Denoting the answer for the query as <span class=\"tex-span\"><i>f</i>(<i>x</i><sub class=\"lower-index\">1</sub>, <i>y</i><sub class=\"lower-index\">1</sub>, <i>x</i><sub class=\"lower-index\">2</sub>, <i>y</i><sub class=\"lower-index\">2</sub>)</span>, we can see that <span class=\"tex-span\"><i>f</i>(<i>x</i><sub class=\"lower-index\">1</sub>, <i>y</i><sub class=\"lower-index\">1</sub>, <i>x</i><sub class=\"lower-index\">2</sub>, <i>y</i><sub class=\"lower-index\">2</sub>) = <i>R</i>(<i>x</i><sub class=\"lower-index\">1</sub>, <i>x</i><sub class=\"lower-index\">2</sub>) + <i>C</i>(<i>y</i><sub class=\"lower-index\">1</sub>, <i>y</i><sub class=\"lower-index\">2</sub>) - <i>A</i></span> (you can draw a simple diagram and validate this function).</p><p>Thus, the problem is now reduced to calculating <span class=\"tex-span\"><i>R</i>(<i>x</i><sub class=\"lower-index\">1</sub>, <i>x</i><sub class=\"lower-index\">2</sub>)</span>, <span class=\"tex-span\"><i>C</i>(<i>y</i><sub class=\"lower-index\">1</sub>, <i>y</i><sub class=\"lower-index\">2</sub>)</span> and <span class=\"tex-span\"><i>A</i></span>:</p> <ul> <li><span class=\"tex-span\"><i>A</i></span> can be easily calculated. After each query of the 1st type with parameters <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">1</sub></span>, <span class=\"tex-span\"><i>y</i><sub class=\"lower-index\">1</sub></span>, <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">2</sub></span>, <span class=\"tex-span\"><i>y</i><sub class=\"lower-index\">2</sub></span>, <span class=\"tex-span\"><i>v</i></span>; <span class=\"tex-span\"><i>A</i></span> will be increased by <span class=\"tex-span\"><i>v</i>·(<i>x</i><sub class=\"lower-index\">2</sub> - <i>x</i><sub class=\"lower-index\">1</sub> + 1)·(<i>y</i><sub class=\"lower-index\">2</sub> - <i>y</i><sub class=\"lower-index\">1</sub> + 1)</span>.</li> <li>The calculation of <span class=\"tex-span\"><i>R</i>(<i>x</i><sub class=\"lower-index\">1</sub>, <i>x</i><sub class=\"lower-index\">2</sub>)</span> and <span class=\"tex-span\"><i>C</i>(<i>y</i><sub class=\"lower-index\">1</sub>, <i>y</i><sub class=\"lower-index\">2</sub>)</span> makes us thinking about some kinds of data structures that support range sum update and range sum query. Segment trees and Fenwick trees can both work on that. Personally I used segment trees, they fit in just right for the memory limit (I implemented it by vectors, regular arrays will obviously be safer).</li> </ul><p>Time complexity: <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/88dba0191e24dada9126d8d5b164d4ade4f556d6.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />.</p></div></div> <div class=\"spoiler\"><b class=\"spoiler-title\">Solution</b><div class=\"spoiler-content\" style=\"display: none;\"><p>Submission link: <a href=\"/contest/390/submission/48213830\" title=\"Посылка 48213830 от AkiLotus\">48213830</a></p> <div class=\"spoiler\"><b class=\"spoiler-title\">Source code in plain text</b><div class=\"spoiler-content\" style=\"display: none;\"><pre><code>#pragma GCC optimize("Ofast")\n\n#include <bits/stdc++.h>\nusing namespace std;\n\n#define endl '\\n'\nmt19937 rng32(chrono::steady_clock::now().time_since_epoch().count());\nmt19937_64 rng64(chrono::steady_clock::now().time_since_epoch().count());\n\nstruct SegTree_Sum {\n\tint n; vector<long long> Tree, Lazy;\n\tSegTree_Sum() {}\n\tSegTree_Sum(int _n) {\n\t\tn = _n;\n\t\tTree.resize(n*4);\n\t\tLazy.resize(n*4);\n\t}\n\t\n\tvoid Propagate(int node, int st, int en) {\n\t\tif (Lazy[node] == 0) return;\n\t\tTree[node] += Lazy[node] * (en - st + 1);\n\t\tif (st != en) {\n\t\t\tLazy[node*2+1] += Lazy[node];\n\t\t\tLazy[node*2+2] += Lazy[node];\n\t\t}\n\t\tLazy[node] = 0;\n\t}\n\t\n\tvoid Update(int node, int st, int en, int L, int R, long long val) {\n\t\tPropagate(node, st, en);\n\t\tif (en < st || R < st || en < L) return;\n\t\tif (L <= st && en <= R) {\n\t\t\tLazy[node] += val;\n\t\t\tPropagate(node, st, en); return;\n\t\t}\n\t\tUpdate(node*2+1, st, (st+en)/2+0, L, R, val);\n\t\tUpdate(node*2+2, (st+en)/2+1, en, L, R, val);\n\t\tTree[node] = Tree[node*2+1] + Tree[node*2+2];\n\t}\n\t\n\tlong long Sum(int node, int st, int en, int L, int R) {\n\t\tPropagate(node, st, en);\n\t\tif (en < st || R < st || en < L) return 0LL;\n\t\tif (L <= st && en <= R) return Tree[node];\n\t\tlong long p1 = Sum(node*2+1, st, (st+en)/2+0, L, R);\n\t\tlong long p2 = Sum(node*2+2, (st+en)/2+1, en, L, R);\n\t\treturn (p1 + p2);\n\t}\n\t\n\tvoid RangeUpdate(int L, int R, long long val) {\n\t\tUpdate(0, 0, n-1, L, R, val);\n\t}\n\t\n\tlong long RangeSum(int L, int R) {\n\t\treturn Sum(0, 0, n-1, L, R);\n\t}\n};\n\nint main(int argc, char* argv[]) {\n\tios_base::sync_with_stdio(0); cin.tie(NULL);\n\t\n\tint n, m, w; cin >> n >> m >> w;\n\t\n\tlong long TotalCandies = 0;\n\t\n\tSegTree_Sum TreeRow = SegTree_Sum(n);\n\tSegTree_Sum TreeCol = SegTree_Sum(m);\n\t\n\twhile (w--) {\n\t\tint t, x1, y1, x2, y2;\n\t\tcin >> t >> x1 >> y1 >> x2 >> y2;\n\t\t\n\t\tif (t == 0) {\n\t\t\tint v; cin >> v;\n\t\t\t\n\t\t\tTotalCandies += 1LL * (x2 - x1 + 1) * (y2 - y1 + 1) * v;\n\t\t\t\n\t\t\tTreeRow.RangeUpdate(x1, x2, 1LL * v * (y2 - y1 + 1));\n\t\t\tTreeCol.RangeUpdate(y1, y2, 1LL * v * (x2 - x1 + 1));\n\t\t}\n\t\telse if (t == 1) {\n\t\t\tlong long res = 0;\n\t\t\t\n\t\t\tres += TreeRow.RangeSum(x1, x2);\n\t\t\tres += TreeCol.RangeSum(y1, y2);\n\t\t\tres -= TotalCandies;\n\t\t\t\n\t\t\tcout << res << endl;\n\t\t}\n\t}\n\t\n\treturn 0;\n}\n</code></pre></div></div></div></div></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/390\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 229 (Div. 2)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-87995-64858\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"87995\",\n blogEntryId: \"64453\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n <div style=\"font-size: 1.1rem;line-height: 11px;\">\r\n <img style=\"vertical-align: middle;\" src=\"//codeforces.org/s/81027/images/blog/tags.png\" title=\"Tags\" alt=\"Tags\"/>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=codeforces\" class=\"tag notice\" style=\"text-decoration: none;\">codeforces</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=229\" class=\"tag notice\" style=\"text-decoration: none;\">229</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=editorial\" class=\"tag notice\" style=\"text-decoration: none;\">editorial</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=second+division\" class=\"tag notice\" style=\"text-decoration: none;\">second division</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=unofficial\" class=\"tag notice\" style=\"text-decoration: none;\">unofficial</a>\r\n </span>\r\n </div>\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-64858\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+37</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-64858\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/AkiLotus\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/AkiLotus\">\n AkiLotus\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Jan/11/2019 15:40\">5 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/64453#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/64453#comments\">\n 7\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"67789\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (7)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"483591\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/stringray\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/575608/avatar/2902babcf56868a2.jpg'/> </a>\n <div><a href=\"/profile/stringray\" title=\"Expert stringray\" class=\"rated-user user-blue\">stringray</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/11/2019 16:50\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-483591\" href=\"?#comment-483591\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"483591\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"575608\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-483591\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>thanks.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-483591 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-483591 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-483591\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"483886\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/caojiangxia\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/374616/avatar/c98eb6a36d8f2853.jpg'/> </a>\n <div><a href=\"/profile/caojiangxia\" title=\"Expert caojiangxia\" class=\"rated-user user-blue\">caojiangxia</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/12/2019 08:51\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-483886\" href=\"?#comment-483886\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"483886\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"374616\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-483886\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Good Job</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-483886 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-483886 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-483886\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"484101\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/MaliceX\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/763085/avatar/45ebf84daf0a0fb6.jpg'/> </a>\n <div><a href=\"/profile/MaliceX\" title=\"Candidate Master MaliceX\" class=\"rated-user user-violet\">MaliceX</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/12/2019 18:35\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-484101\" href=\"?#comment-484101\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"484101\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"11\"\r\n data-commentUserId=\"763085\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+11</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-484101\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Already the account with most ACs in the country, what a hard-working person!</p><p>Did you find this contest by accident or have you done it all the way back there ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-484101 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-484101 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-484101\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"484104\" commentParentId=\"484101\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/AkiLotus\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/562732/avatar/374a86575dcbea6a.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/AkiLotus\" title=\"Master AkiLotus\" class=\"rated-user user-orange\">AkiLotus</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/12/2019 18:36\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-484104\" href=\"?#comment-484104\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-484101\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"484104\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"13\"\r\n data-commentUserId=\"562732\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+13</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-484104\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I just came across it while searching for some relaxing undone contest to do virtual, then I found this :D</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-484104 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-484104 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-484104\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"484114\" commentParentId=\"484104\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/MaliceX\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/763085/avatar/45ebf84daf0a0fb6.jpg'/> </a>\n <div><a href=\"/profile/MaliceX\" title=\"Candidate Master MaliceX\" class=\"rated-user user-violet\">MaliceX</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/12/2019 19:01\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-484114\" href=\"?#comment-484114\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-484104\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"484114\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"763085\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-484114\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>What is your motivation to train so hard ? I want to be as good as you are, but I'm so lazy xD</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-484114 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-484114 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-484114\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"484116\" commentParentId=\"484114\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/AkiLotus\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/562732/avatar/374a86575dcbea6a.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/AkiLotus\" title=\"Master AkiLotus\" class=\"rated-user user-orange\">AkiLotus</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/12/2019 19:04\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-484116\" href=\"?#comment-484116\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-484114\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"484116\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"13\"\r\n data-commentUserId=\"562732\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+13</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-484116\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I'm quite of a guy with innate self-motivating ability :D</p><p>Also, tbh, I have only stepped into CP since college, which is way late compared to many other guys. To fill the gap, guess I have no better choice but double my efforts ;)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-484116 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-484116 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-484116\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"486236\" commentParentId=\"484116\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/SonDinh\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/722820/avatar/14ca0ac05fda3ca0.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/SonDinh\" title=\"Expert SonDinh\" class=\"rated-user user-blue\">SonDinh</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/22/2019 17:13\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-486236\" href=\"?#comment-486236\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-484116\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"486236\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"722820\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-486236\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I really admire you, how much time do you spend a day to practise CP?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-486236 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-486236 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-486236\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n <br/>\r\n\r\n<div id=\"editBox-67789\" style=\"width:50em;display:none;\">\r\n <div class=\"previewBody\" style=\"border: 1px solid #d4d4d4; margin-bottom: 0.5em; padding: 0.25em; display:none;\"> </div>\r\n <div style=\"width: 1px\"> </div>\r\n <div class=\"commentLocale\" style=\"position: relative; top: 0.5em;left:4px;display: none;\">\r\n <input type=\"radio\" name=\"locale\" value=\"en\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In English</span>\r\n <input style=\"margin-left:1em\" type=\"radio\" name=\"locale\" value=\"ru\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In Russian</span>\r\n </div>\r\n <textarea data-drafts-id=\"CommentReplyFrame\" class=\"wysiwyg\" name=\"editContent\" rows=\"20\" style=\"width:99%;\"></textarea>\r\n <div class=\"error error__content\"></div>\r\n <div style=\"text-align:center;\">\r\n <input type=\"button\" name=\"preview\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Preview\"/>\r\n <input type=\"button\" name=\"save\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Save\"/>\r\n </div>\r\n</div>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n\r\nvar firstPreview67789 = true;\r\nvar lastPreviewContent67789 = '';\r\n\r\nif (!window.moveCommentRevision) {\r\n moveCommentRevision = function(e, dir) {\r\n var p = e.parent();\r\n var revisionCount = parseInt(p.attr(\"revisionCount\"));\r\n var revision = parseInt(p.attr(\"revision\"));\r\n var next = revision + dir;\r\n var commentId = p.attr(\"commentId\");\r\n if (next >= 1 && next <= revisionCount) {\r\n $.post(\r\n \"/data/comment-data\",\r\n {action: \"revision\", commentId: commentId, revision: next},\r\n function(json) {\r\n if (json.success == \"true\") {\r\n var parentDiv = e;\r\n\r\n while (parentDiv !== null && (parentDiv[0].nodeName.toLowerCase() !== \"td\" || !parentDiv.hasClass(\"right\"))) {\r\n parentDiv = parentDiv.parent();\r\n }\r\n\r\n if (parentDiv === null) {\r\n return;\r\n }\r\n\r\n parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\").html(json.content);\r\n Codeforces.setupSpoilers(parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\"));\r\n p.attr(\"revision\", next);\r\n p.find(\"span.revision\").text(next);\r\n if (next == 1) {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"visible\");\r\n }\r\n if (next == revisionCount) {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"visible\");\r\n }\r\n\r\n window.updateTypography();\r\n MathJax.Hub.Typeset();\r\n } else {\r\n alert(e.error);\r\n }\r\n },\r\n \"json\"\r\n );\r\n }\r\n };\r\n}\r\n\r\n$(\"div[commentableId=67789] a.leftRevision\").click(function () {\r\n window.moveCommentRevision($(this), -1);\r\n return false;\r\n});\r\n\r\n$(\"div[commentableId=67789] a.rightRevision\").click(function () {\r\n window.moveCommentRevision($(this), +1);\r\n return false;\r\n});\r\n\r\n\r\n\r\n });\n </script>\n\r\n\r\n <script src=\"//codeforces.org/s/81027/js/swfobject-2.2.min.js\" type=\"text/javascript\"></script>\n <script src=\"//codeforces.org/s/81027/js/ftaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n if (window.evercookie) {\n var ec = new evercookie({\n history: false,\n silverlight: false,\n baseurl: '',\n asseturi: '/assets',\n phpuri: '/2fdcd78',\n pngPath: '/eps',\n etagPath: '/ees',\n cachePath: '/ecs'\n });\n\n var randomNumber = function () {\n return Math.random().toString(36).substr(2);\n };\n\n var randomToken = function () {\n return (randomNumber() + randomNumber()).substring(0, 18);\n };\n\n window._ftaa = \"\";\n\n ec.get(\"70a7c28f3de\", function (value) {\n window._ftaa = value;\n if (!window._ftaa) {\n window._ftaa = randomToken();\n ec.set(\"70a7c28f3de\", window._ftaa);\n }\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n } else {\n window._ftaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\n <script src=\"//codeforces.org/s/81027/js/bfaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n var fpCallback = function() {\n Fingerprint2.get({}, function(components) {\n window._bfaa = Fingerprint2.x64hash128(components.map(function (pair) { return pair.value }).join(), 31);\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n };\n if (typeof Fingerprint2 !== 'undefined') {\n if (window.requestIdleCallback) {\n requestIdleCallback(fpCallback)\n } else {\n setTimeout(fpCallback, 500)\n }\n } else {\n window._bfaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"a.new-root-comment\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n\r\n $(\".comment-table .reply a\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".vote-for-comment\").mouseover(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").mouseout(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").click(function () {\r\n var vote = $(this);\r\n var commentId = $(this).parent().attr(\"commentid\");\r\n var commentRating = $(this).parent().attr(\"data-commentRating\");\r\n var direction = $(this).attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n $.post(\"/data/comment/vote\", {commentId: commentId, _tta: Codeforces.tta(), vote: direction, commentRating: commentRating}, function(data) {\r\n if (direction != 0 && !ownComment && data[\"success\"] == \"true\") {\r\n vote.parent().find(\".vote-for-comment\").attr(\"voteDirection\", 0);\r\n if (direction == 1)\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n else {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.closest(\".CommentVoteFrame\").find(\".ComplaintFrame\").css(\"display\", \"inline-block\");\r\n }\r\n vote.find(\"img\").attr(\"popacity\", \"1.0\");\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n vote.parent().find(\".commentRating\").html(data[\"commentRating\"]);\r\n }\r\n Codeforces.showMessage(data[\"message\"]);\r\n }, \"json\");\r\n return false;\r\n });\r\n\r\n $(\".negative-comment-vote\").closest(\".comment-table\").addClass(\"comment-bad\");\r\n\r\n $(\".troll-comment-vote\").closest(\".comment\").css(\"display\", \"none\");\r\n\r\n $(\".too-negative-comment-vote\").closest(\".comment-table\").each(function () {\r\n var e = $(this);\r\n e.addClass(\"comment-too-bad\");\r\n var commentId = e.attr(\"commentId\");\r\n $(\"<div class='bad-comment-replacement ttypography'>The comment is hidden because of too negative feedback, click <a href=# class=show-bad-comment-link>here</a> to view it</div>\").appendTo(\r\n e.find(\".right\")\r\n );\r\n e.find(\".comment-content\").hide();\r\n e.find(\".show-bad-comment-link\").click(function () {\r\n e.find(\".comment-content\").show();\r\n e.find(\".bad-comment-replacement\").hide();\r\n return false;\r\n });\r\n });\r\n });\n </script>\n </div>\r\n\r\n <style type=\"text/css\">\r\n .new-comments-box {\r\n padding: 0.5em;\r\n width: 22px;\r\n font-size: 1.3rem;\r\n font-weight: bold !important;\r\n\r\n position: fixed;\r\n top: 40%;\r\n right: 0;\r\n opacity: 0.2;\r\n color: white;\r\n text-align: center;\r\n\r\n border: 1px solid #222;\r\n background-color: #888 !important;\r\n border-radius: 3px;\r\n -moz-border-radius: 3px;\r\n -webkit-border-radius: 3px;\r\n }\r\n\r\n .new-comments-box:hover {\r\n opacity: 1;\r\n }\r\n\r\n .new-comments-box .dir:hover {\r\n background: #3B5998 !important;\r\n cursor: pointer;\r\n }\r\n </style>\r\n\r\n <div class=\"new-comments-box\" data-position=\"outside\" data-index=\"-1\" style=\"display: none;\">\r\n <div class=\"up dir\" title=\"Ctrl+Up\">↑<hr/>\r\n </div>\r\n <div class=\"info\" title=\"New comments\"></div>\r\n <div class=\"down dir\" title=\"Ctrl+Down\">\r\n <hr/>↓\r\n </div>\r\n </div>\r\n\r\n <script>\r\n $(\".show-archived-checkbox\").change(function () {\r\n const checked = $(this).is(\":checked\");\r\n $.post(\"/data/comment-data\", {action: \"setShowArchived\", checked}, function (json) {\r\n if (json[\"success\"] !== \"true\") {\r\n alert(json[\"error\"]);\r\n } else {\r\n if (checked) {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are now displayed\")\r\n } else {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are no longer displayed\")\r\n }\r\n }\r\n });\r\n return false;\r\n });\r\n\r\n function gotoComment(direction) {\r\n var box = $(\".new-comments-box\");\r\n var index = parseInt(box.attr(\"data-index\"));\r\n if (index == -1)\r\n index = 0;\r\n else\r\n index = Math.max(0, Math.min(parseInt(box.find(\".info\").text()) - 1, index + direction));\r\n box.attr(\"data-index\", index);\r\n var comment = $($(\".comment .highlight-blue[commentId]\").get(index));\r\n $('html, body').animate({\r\n 'scrollTop': Math.max(0, comment.offset().top - ($(window).height() - comment.height()) / 2)\r\n });\r\n return false;\r\n }\r\n\r\n $(\".new-comments-box .down\").click(function () {\r\n return gotoComment(1);\r\n });\r\n\r\n $(\".new-comments-box .up\").click(function () {\r\n return gotoComment(-1);\r\n });\r\n\r\n $(document).keydown(function (e) {\r\n var code = (e.keyCode ? e.keyCode : e.which);\r\n if (e.ctrlKey) {\r\n if (code == 38 || code == 40) {\r\n gotoComment(code - 39);\r\n }\r\n }\r\n });\r\n\r\n var newCommentCount = $(\".comment .highlight-blue[commentId]\").length;\r\n if (newCommentCount > 0) {\r\n $(\".new-comments-box .info\").text(newCommentCount);\r\n $(\".new-comments-box\").show();\r\n }\r\n\r\n $('table.comment-table').mouseenter(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").addClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n\r\n $('table.comment-table').mouseleave(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").removeClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n </script>\r\n\r\n\r\n\r\n <script>\r\n function adjustTopicComplainFrames() {\r\n let topicIds = [];\r\n\r\n $(\".has-topic-id\").each(function () {\r\n const $this = $(this);\r\n const topicId = $this.attr(\"topicId\");\r\n if (topicId) {\r\n topicIds.push(topicId);\r\n }\r\n });\r\n\r\n $.post(\"/data/topics\", {\r\n action: \"findComplainableTopicIds\",\r\n topicIds: topicIds.join(\",\")\r\n }, function (json) {\r\n if (json[\"success\"] === \"true\") {\r\n for (const topicId of json[\"complainableTopicIds\"].split(\",\")) {\r\n $(\".has-topic-id[topicId=\" + topicId + \"]\").each(function () {\r\n $(this).find(\".meta .ComplaintFrame\").css(\"display\", \"inline-block\");\r\n });\r\n }\r\n }\r\n }, \"json\");\r\n }\r\n\r\n $(function () {\r\n adjustTopicComplainFrames();\r\n })\r\n </script>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-64858\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 64858, _tta: Codeforces.tta(), topicRevisionId: 152874, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-64858\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 64858, _tta: Codeforces.tta(), topicRevisionId: 152874, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n </div>\r\n </div>\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 22:13:08</span> (h1).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/81027/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/81027/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/81027/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/81027/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-81027.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'812875abea0b9d76',t:'MTY5NjcwNTk4OC41NjQwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"}}},{"rowIdx":1969,"cells":{"problem_id":{"kind":"string","value":"390B"},"contest":{"kind":"string","value":"390"},"problem":{"kind":"string","value":"B"},"lang":{"kind":"string","value":"en"},"problem_title":{"kind":"string","value":"B. Inna, Dima and Song"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">B. Inna, Dima and Song</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Inna is a great piano player and Dima is a modest guitar player. Dima has recently written a song and they want to play it together. Of course, Sereja wants to listen to the song very much. </p><p>A song is a sequence of notes. Dima and Inna want to play each note at the same time. At that, they can play the <span class=\"tex-span\"><i>i</i></span>-th note at volume <span class=\"tex-span\"><i>v</i></span> (<span class=\"tex-span\">1 ≤ <i>v</i> ≤ <i>a</i><sub class=\"lower-index\"><i>i</i></sub></span>; <span class=\"tex-span\"><i>v</i></span> is an integer) both on the piano and the guitar. They should retain harmony, so the total volume with which the <span class=\"tex-span\"><i>i</i></span>-th note was played on the guitar and the piano must equal <span class=\"tex-span\"><i>b</i><sub class=\"lower-index\"><i>i</i></sub></span>. If Dima and Inna cannot play a note by the described rules, they skip it and Sereja's joy drops by 1. But if Inna and Dima play the <span class=\"tex-span\"><i>i</i></span>-th note at volumes <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span> and <span class=\"tex-span\"><i>y</i><sub class=\"lower-index\"><i>i</i></sub></span> <span class=\"tex-span\">(<i>x</i><sub class=\"lower-index\"><i>i</i></sub> + <i>y</i><sub class=\"lower-index\"><i>i</i></sub> = <i>b</i><sub class=\"lower-index\"><i>i</i></sub>)</span> correspondingly, Sereja's joy rises by <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub>·<i>y</i><sub class=\"lower-index\"><i>i</i></sub></span>. </p><p>Sereja has just returned home from the university and his current joy is 0. Help Dima and Inna play the song so as to maximize Sereja's total joy after listening to the whole song!</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line of the input contains integer <span class=\"tex-span\"><i>n</i></span> <span class=\"tex-span\">(1 ≤ <i>n</i> ≤ 10<sup class=\"upper-index\">5</sup>)</span> — the number of notes in the song. The second line contains <span class=\"tex-span\"><i>n</i></span> integers <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> <span class=\"tex-span\">(1 ≤ <i>a</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 10<sup class=\"upper-index\">6</sup>)</span>. The third line contains <span class=\"tex-span\"><i>n</i></span> integers <span class=\"tex-span\"><i>b</i><sub class=\"lower-index\"><i>i</i></sub></span> <span class=\"tex-span\">(1 ≤ <i>b</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 10<sup class=\"upper-index\">6</sup>)</span>.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>In a single line print an integer — the maximum possible joy Sereja feels after he listens to a song.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>3<br/>1 1 2<br/>2 2 3<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>4<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>1<br/>2<br/>5<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>-1<br/></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>In the first sample, Dima and Inna play the first two notes at volume <span class=\"tex-span\">1</span> (<span class=\"tex-span\">1 + 1 = 2</span>, the condition holds), they should play the last note at volumes <span class=\"tex-span\">1</span> and <span class=\"tex-span\">2</span>. Sereja's total joy equals: <span class=\"tex-span\">1·1 + 1·1 + 1·2 = 4</span>.</p><p>In the second sample, there is no such pair <span class=\"tex-span\">(<i>x</i>, <i>y</i>)</span>, that <span class=\"tex-span\">1 ≤ <i>x</i>, <i>y</i> ≤ 2</span>, <span class=\"tex-span\"><i>x</i> + <i>y</i> = 5</span>, so Dima and Inna skip a note. Sereja's total joy equals -1.</p></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"77a5713215519bf438eb1daf11e47824\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - B - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"d468883313d2f01f0365840b13075e5c5bb1675c\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - B - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/73366/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/73366/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/73366/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/73366/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/73366/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/73366/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/73366/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/73366/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/73366/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/73366/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/73366/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/73366/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/73366/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/73366/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/sidebar-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/a037fe51637846d9c7c725713cd840ea/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='77a5713215519bf438eb1daf11e47824'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/73366/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/73366/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fcontest%2F390%2Fproblem%2FB%3Flocale%3Den\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"current\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='77a5713215519bf438eb1daf11e47824'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:100%;\"><a style=\"color: black\" href=\"/contest/390\">Codeforces Round 229 (Div. 2)</a></th>\n </tr>\n <tr>\n <td class=\"left bottom\" colspan=\"1\"><span class=\"contest-state-phase\">Finished</span></td>\n </tr>\n </tbody>\n </table>\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Practice?\n <div class=\"top-links\">\n </div>\n </div>\n<div>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Want to solve the contest problems after the official contest ends? Just register for practice and you will be able to submit solutions.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"\" method=\"post\"><input type='hidden' name='csrf_token' value='77a5713215519bf438eb1daf11e47824'/>\r\n <input type=\"hidden\" name=\"action\" value=\"registerForPractice\"/>\r\n <input type=\"submit\" name=\"submit\" value=\"Register for practice\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div> \r\n</div>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox ContestVirtualFrame borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Virtual participation <i class=\"sidebar-caption-icon las la-angle-down\"></i>\r\n\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\" \"\r\n\r\n data-page-url=\"/data/sidebarFrames\"\r\n\r\n>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests.\n\nIf you've seen these problems, a virtual contest is not for you - solve these problems in the archive.\n\nIf you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.\n\nNever use someone else's code, read the tutorials or communicate with other person during a virtual contest.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"/contest/390/virtual\" method=\"get\">\r\n <input type=\"submit\" name=\"submit\" value=\"Start virtual contest\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div>\r\n</div>\r\n <script>\r\n $(function () {\r\n $(\".ContestVirtualFrame .sidebar-caption-icon\").click(function() {\r\n $(this).toggleClass(\"la-angle-down la-angle-right\");\r\n const $target = $(this).parent().next();\r\n $target.toggle();\r\n const dataPageUrl = $target.attr(\"data-page-url\");\r\n const collapsed = $(this).hasClass(\"la-angle-right\");\r\n const params = {\r\n action: \"setCollapsed\",\r\n sidebarFrameSimpleClassName: \"ContestVirtualFrame\",\r\n collapsed\r\n };\r\n $.each($target[0].attributes, function(i, a) {\r\n const name = a.name;\r\n if (name.startsWith(\"data-extra-key-\")) {\r\n const key = a.value;\r\n const keyIndex = parseInt(name.substring(\"data-extra-key-\".length));\r\n const value = $target.attr(\"data-extra-value-\" + keyIndex);\r\n params[key] = value;\r\n }\r\n });\r\n $.post(dataPageUrl, params, function (result) {\r\n if (result[\"success\"] !== \"true\") {\r\n Codeforces.showMessage(\"Failed to save collapsed state.\");\r\n }\r\n }, \"json\");\r\n return false;\r\n });\r\n })\r\n </script>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Problem tags\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Implementation problems, programming technics, simulation\">\r\n implementation\r\n</span>\r\n </div>\n <div style=\"clear:both;text-align:right;font-size:1.1rem;\">\r\n <span title=\"Please login into the Codeforces\" class=\"notice\">No tag edit access</span>\r\n </div>\r\n</div>\r\n </div>\n\r\n<form id=\"addTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='77a5713215519bf438eb1daf11e47824'/>\r\n <input name=\"action\" type=\"hidden\" value=\"addTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"6703\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<form id=\"removeTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='77a5713215519bf438eb1daf11e47824'/>\r\n <input name=\"action\" type=\"hidden\" value=\"removeTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"6703\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<script type=\"text/javascript\">\r\n $(\".tag-box img\").click(function () {\r\n var tagName = $(this).attr(\"value\");\r\n Codeforces.confirm(\"Are you sure you want to remove this tag?\", function () {\r\n $(\"#removeTagForm input[name=tagName]\").val(tagName);\r\n $(\"#removeTagForm\").submit();\r\n }, function () {\r\n }, \"Yes\", \"No\");\r\n });\r\n\r\n $(\"#addTagLink\").click(function () {\r\n $(this).hide();\r\n $(\"#addTagLabel\").show();\r\n return false;\r\n });\r\n\r\n $(\"#addTagSelect\").change(function () {\r\n var tagName = $(this).val();\r\n if (tagName === \"\") {\r\n $(\"#addTagLabel\").hide();\r\n $(\"#addTagLink\").show();\r\n } else {\r\n $(\"#addTagForm input[name=tagName]\").val(tagName);\r\n $(\"#addTagForm\").submit();\r\n }\r\n });\r\n</script>\r\n\r\n<style type=\"text/css\">\r\n#new-resource-form tr td {\r\npadding-top: 0.5em;\r\n}\r\n#new-resource-form input:not([type=\"submit\"]) {\r\nfont-size: 0.8em;\r\n}\r\n#new-resource-form select {\r\nfont-size: 0.8em;\r\n}\r\n.new-resource-error {\r\nfont-size: 0.8em;\r\n}\r\n.resource-locale {\r\ncolor: #666;\r\nfont-family: Consolas, \"Andale Mono WT\", \"Andale Mono\", \"Lucida Console\", \"Lucida Sans Typewriter\", \"DejaVu Sans Mono\", \"Bitstream Vera Sans Mono\", \"Liberation Mono\", \"Nimbus Mono L\", Monaco, \"Courier New\", Courier, monospace;\r\n}\r\n</style>\r\n<div class=\"roundbox sidebox sidebar-menu borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Contest materials\n<div class=\"top-links\">\n</div>\n</div>\n<ul>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/64453\" title=\"Editorial (Unofficial)\" target=\"_blank\">Editorial (Unofficial) <span class=\"resource-locale\">(en)</span></a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"17239\" resourceName=\"Editorial (Unofficial)\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n</ul>\r\n</div></div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li class=\"current selectedLava\"><a\r\n href=\"/contest/390\">Problems</a></li>\r\n <li><a\r\n href=\"/contest/390/submit\">Submit Code</a></li>\r\n <li><a\r\n href=\"/contest/390/my\">My Submissions</a></li>\r\n <li><a\r\n href=\"/contest/390/status\">Status</a></li>\r\n <li><a\r\n href=\"/contest/390/hacks\">Hacks</a></li>\r\n <li><a\r\n href=\"/contest/390/room/1\">Room</a></li>\r\n <li><a\r\n href=\"/contest/390/standings\">Standings</a></li>\r\n <li><a\r\n href=\"/contest/390/customtest\">Custom Invocation</a></li>\r\n</ul>\r\n</div>\n\r\n <style>\r\n #facebox .content:has(.diff-popup) {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n }\r\n\r\n .testCaseMarker {\r\n position: absolute;\r\n font-weight: bold;\r\n font-size: 1rem;\r\n }\r\n\r\n .diff-popup {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n display: none;\r\n overflow: auto;\r\n }\r\n\r\n .input-output-copier {\r\n font-size: 1.2rem;\r\n float: right;\r\n color: #888 !important;\r\n cursor: pointer;\r\n border: 1px solid rgb(185, 185, 185);\r\n padding: 3px;\r\n margin: 1px;\r\n line-height: 1.1rem;\r\n text-transform: none;\r\n }\r\n\r\n .input-output-copier:hover {\r\n background-color: #def;\r\n }\r\n\r\n .test-explanation textarea {\r\n width: 100%;\r\n height: 1.5em;\r\n }\r\n\r\n .pending-submission-message {\r\n color: darkorange !important;\r\n }\r\n </style>\r\n <script>\r\n const OPENING_SPACE = String.fromCharCode(1001);\r\n const CLOSING_SPACE = String.fromCharCode(1002);\r\n\r\n const nodeToText = function (node, pre) {\r\n let result = [];\r\n\r\n if (node.tagName === \"SCRIPT\" || node.tagName === \"math\"\r\n || (node.classList && node.classList.contains(\"input-output-copier\")))\r\n return [];\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(OPENING_SPACE);\r\n }\r\n\r\n if (node.nodeType === Node.TEXT_NODE) {\r\n let s = node.textContent;\r\n if (!pre) {\r\n s = s.replace(/\\s+/g, \" \");\r\n }\r\n if (s.length > 0) {\r\n result.push(s);\r\n }\r\n }\r\n\r\n if (pre && node.tagName === \"BR\") {\r\n result.push(\"\\n\");\r\n }\r\n\r\n node.childNodes.forEach(function (child) {\r\n result.push(nodeToText(child, node.tagName === \"PRE\").join(\"\"));\r\n });\r\n\r\n if (node.tagName === \"DIV\"\r\n || node.tagName === \"P\"\r\n || node.tagName === \"PRE\"\r\n || node.tagName === \"UL\"\r\n || node.tagName === \"LI\"\r\n ) {\r\n result.push(\"\\n\");\r\n }\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(CLOSING_SPACE);\r\n }\r\n\r\n return result;\r\n }\r\n\r\n const isSpecial = function (c) {\r\n return c === ',' || c === '.' || c === ';' || c === ')' || c === ' ';\r\n }\r\n\r\n const convertStatementToText = function(statmentNode) {\r\n const text = nodeToText(statmentNode, false).join(\"\").replace(/ +/g, \" \").replace(/\\n\\n+/g, \"\\n\\n\");\r\n let result = [];\r\n for (let i = 0; i < text.length; i++) {\r\n const c = text.charAt(i);\r\n if (c === OPENING_SPACE) {\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"B\" data-uuid=\"ps_e84f58f038f8e5e803d719b11ab509714d850c57\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">B. Inna, Dima and Song</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Inna is a great piano player and Dima is a modest guitar player. Dima has recently written a song and they want to play it together. Of course, Sereja wants to listen to the song very much. </p><p>A song is a sequence of notes. Dima and Inna want to play each note at the same time. At that, they can play the <span class=\"tex-span\"><i>i</i></span>-th note at volume <span class=\"tex-span\"><i>v</i></span> (<span class=\"tex-span\">1 ≤ <i>v</i> ≤ <i>a</i><sub class=\"lower-index\"><i>i</i></sub></span>; <span class=\"tex-span\"><i>v</i></span> is an integer) both on the piano and the guitar. They should retain harmony, so the total volume with which the <span class=\"tex-span\"><i>i</i></span>-th note was played on the guitar and the piano must equal <span class=\"tex-span\"><i>b</i><sub class=\"lower-index\"><i>i</i></sub></span>. If Dima and Inna cannot play a note by the described rules, they skip it and Sereja's joy drops by 1. But if Inna and Dima play the <span class=\"tex-span\"><i>i</i></span>-th note at volumes <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span> and <span class=\"tex-span\"><i>y</i><sub class=\"lower-index\"><i>i</i></sub></span> <span class=\"tex-span\">(<i>x</i><sub class=\"lower-index\"><i>i</i></sub> + <i>y</i><sub class=\"lower-index\"><i>i</i></sub> = <i>b</i><sub class=\"lower-index\"><i>i</i></sub>)</span> correspondingly, Sereja's joy rises by <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub>·<i>y</i><sub class=\"lower-index\"><i>i</i></sub></span>. </p><p>Sereja has just returned home from the university and his current joy is 0. Help Dima and Inna play the song so as to maximize Sereja's total joy after listening to the whole song!</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line of the input contains integer <span class=\"tex-span\"><i>n</i></span> <span class=\"tex-span\">(1 ≤ <i>n</i> ≤ 10<sup class=\"upper-index\">5</sup>)</span> — the number of notes in the song. The second line contains <span class=\"tex-span\"><i>n</i></span> integers <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> <span class=\"tex-span\">(1 ≤ <i>a</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 10<sup class=\"upper-index\">6</sup>)</span>. The third line contains <span class=\"tex-span\"><i>n</i></span> integers <span class=\"tex-span\"><i>b</i><sub class=\"lower-index\"><i>i</i></sub></span> <span class=\"tex-span\">(1 ≤ <i>b</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 10<sup class=\"upper-index\">6</sup>)</span>.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>In a single line print an integer — the maximum possible joy Sereja feels after he listens to a song.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>3<br />1 1 2<br />2 2 3<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>4<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>1<br />2<br />5<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>-1<br /></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>In the first sample, Dima and Inna play the first two notes at volume <span class=\"tex-span\">1</span> (<span class=\"tex-span\">1 + 1 = 2</span>, the condition holds), they should play the last note at volumes <span class=\"tex-span\">1</span> and <span class=\"tex-span\">2</span>. Sereja's total joy equals: <span class=\"tex-span\">1·1 + 1·1 + 1·2 = 4</span>.</p><p>In the second sample, there is no such pair <span class=\"tex-span\">(<i>x</i>, <i>y</i>)</span>, that <span class=\"tex-span\">1 ≤ <i>x</i>, <i>y</i> ≤ 2</span>, <span class=\"tex-span\"><i>x</i> + <i>y</i> = 5</span>, so Dima and Inna skip a note. Sereja's total joy equals -1.</p></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=B]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== statementText) {\r\n $problem.find(\".diff-notifier\").show();\r\n\r\n $problem.find(\".diff-notifier-close\").click(function() {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n $problem.find(\".diff-notifier\").hide();\r\n });\r\n\r\n $problem.find(\"a.view-changes\").click(function() {\r\n $.post(\"/data/diff\", {action: \"getDiff\", a: previousStatementText, b: statementText}, function (result) {\r\n if (result[\"success\"] === \"true\") {\r\n Codeforces.facebox(\".diff-popup\", \"//codeforces.org/s/73366\");\r\n $(\"#facebox .diff-popup\").html(result[\"diff\"]);\r\n }\r\n }, \"json\");\r\n });\r\n }\r\n } else {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n }\r\n });\r\n });\r\n </script>\r\n\r\n\r\n<script type=\"text/javascript\">\r\n $(document).ready(function () {\r\n window.changedTests = new Set();\r\n\r\n function endsWith(string, suffix) {\r\n return string.indexOf(suffix, string.length - suffix.length) !== -1;\r\n }\r\n\r\n const inputFileDiv = $(\"div.input-file\");\r\n const inputFile = inputFileDiv.text();\r\n const outputFileDiv = $(\"div.output-file\");\r\n const outputFile = outputFileDiv.text();\r\n\r\n\r\n if (!endsWith(inputFile, \"standard input\")\r\n && !endsWith(inputFile, \"standard input\")) {\r\n inputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n if (!endsWith(outputFile, \"standard output\")\r\n && !endsWith(outputFile, \"standard output\")) {\r\n outputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n const titleDiv = $(\"div.header div.title\");\r\n\r\n\r\n\r\n String.prototype.replaceAll = function (search, replace) {\r\n return this.split(search).join(replace);\r\n };\r\n\r\n $(\".sample-test .title\").each(function () {\r\n const preId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n const cpyId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n\r\n $(this).parent().find(\"pre\").attr(\"id\", preId);\r\n const $copy = $(\"<div title='Copy' data-clipboard-target='#\" + preId + \"' id='\" + cpyId + \"' class='input-output-copier'>Copy</div>\");\r\n $(this).append($copy);\r\n\r\n const clipboard = new Clipboard('#' + cpyId, {\r\n text: function (trigger) {\r\n const pre = document.querySelector('#' + preId);\r\n const lines = pre.querySelectorAll(\".test-example-line\");\r\n return Codeforces.filterClipboardText(pre.innerText, lines.length);\r\n }\r\n });\r\n\r\n const isInput = $(this).parent().hasClass(\"input\");\r\n\r\n clipboard.on('success', function (e) {\r\n if (isInput) {\r\n Codeforces.showMessage(\"The example input has been copied into the clipboard\");\r\n } else {\r\n Codeforces.showMessage(\"The example output has been copied into the clipboard\");\r\n }\r\n e.clearSelection();\r\n });\r\n });\r\n\r\n $(\".test-form-item input\").change(function () {\r\n addPendingSubmissionMessage($($(this).closest(\"form\")), \"You changed the answer, do not forget to submit it if you want to save the changes\");\r\n const index = $(this).closest(\".problemindexholder\").attr(\"problemindex\");\r\n let test = \"\";\r\n $(this).closest(\"form input\").each(function () {\r\n const test_ = $(this).attr(\"name\");\r\n if (test_ && test_.substring(0, 4) === \"test\") {\r\n test = test_;\r\n }\r\n });\r\n if (index.length > 0 && test.length > 0) {\r\n const indexTest = index + \"::\" + test;\r\n window.changedTests.add(indexTest);\r\n }\r\n });\r\n\r\n $(window).on('beforeunload', function () {\r\n if (window.changedTests.size > 0) {\r\n return 'Dialog text here';\r\n }\r\n });\r\n\r\n autosize($('.test-explanation textarea'));\r\n\r\n $(\".test-example-line\").hover(function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n let top = 1E20;\r\n let left = 1E20;\r\n let problem = $(this).closest(\".problemindexholder\");\r\n $(this).closest(\".input\").find(\".\" + clazz).css(\"background-color\", \"#FFFDE7\").each(function() {\r\n top = Math.min(top, $(this).offset().top);\r\n left = Math.min(left, $(this).offset().left);\r\n });\r\n let testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n if (testCaseMarker.length === 0) {\r\n const html = \"<div class=\\\"testCaseMarker testCaseMarker_\" + end + \" notice\\\"></div>\";\r\n problem.append($(html));\r\n testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n }\r\n if (testCaseMarker) {\r\n testCaseMarker.show()\r\n .offset({top, left: left - 20})\r\n .text(end);\r\n }\r\n }\r\n }\r\n });\r\n }, function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n $(\".\" + clazz).css(\"background-color\", \"\");\r\n $(this).closest(\".problemindexholder\").find(\".testCaseMarker_\" + end).hide();\r\n }\r\n }\r\n });\r\n });\r\n\r\n });\r\n</script>\r\n\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 05:38:44</span> (j3).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/73366/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/73366/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/73366/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/73366/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-73366.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'8122c5060b3c3380',t:'MTY5NjY0NjMyNC4yNTkwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"},"long_tags":{"kind":"string","value":"[\"Implementation problems, programming technics, simulation\"]"},"short_tags":{"kind":"string","value":"[\"implementation\"]"},"tutorial_link":{"kind":"string","value":"https://codeforces.com/blog/entry/64453"},"tutorial_page":{"kind":"string","value":"\r\n\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"642864061f7f8f253cd15a412d138165\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"h1\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Codeforces Round #229 (Div. 2) Editorial [Unofficial] - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n \n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Codeforces Round #229 (Div. 2) Editorial [Unofficial] - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/81027/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/81027/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/81027/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/81027/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/81027/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/81027/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/81027/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/81027/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/81027/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/81027/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/81027/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/81027/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/81027/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/81027/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/573cedc6b04c15481941f418269f4057/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='642864061f7f8f253cd15a412d138165'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/81027/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fblog%2Fentry%2F64453\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='642864061f7f8f253cd15a412d138165'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Pay attention\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n <div style=\"text-align:center;border-bottom: 1px solid rgb(185, 185, 185);margin:0 -0.5em 0.5em -0.5em;padding: 0 1em 0.5em 1em;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 1, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:51:52</span><br/><a href=\"/contestRegistration/1876\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n <div style=\"text-align:center;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 2, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:51:52</span><br/><a href=\"/contestRegistration/1877\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='642864061f7f8f253cd15a412d138165'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n </label>\r\n </div>\r\n <div style=\"padding: 0 1em 1em 1em;text-align:right;\">\r\n <input style=\"height:1.65em;padding:0 0.75em;\" type=\"submit\" value=\"Find\"/>\r\n </div>\r\n </form>\r\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".handleBox\").autocomplete(\"/data/handles\", {\r\n delay: 200,\r\n width: 200,\r\n selectFirst: false,\r\n matchContains: true,\r\n minChars: 3\r\n });\r\n $(\".handleForm\").attr(\"autocomplete\", \"off\").submit(function () {\r\n var link = \"/profile/userHandle\".replace(\r\n \"userHandle\", $(this).find(\".handleBox\").val()\r\n );\r\n window.location = link;\r\n return false;\r\n });\r\n });\n </script>\n\r\n\r\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Recent actions\n <div class=\"top-links\">\n </div>\n </div>\n <div class=\"recent-actions\">\r\n <ul>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/121073\">Meta Hacker Cup 2023 Round 1</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/.Danet\" title=\"Expert .Danet\" class=\"rated-user user-blue\">.Danet</a> →\r\n <a href=\"/blog/entry/121172\">[TLE on pretest1]</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\" class=\"rated-user user-red\">Pyqe</a> →\r\n <a href=\"/blog/entry/121025\">Codeforces Round #902 (Div. 1, Div. 2, based on COMPFEST 15 — Final Round)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pranshu_Pandya\" title=\"Specialist Pranshu_Pandya\" class=\"rated-user user-cyan\">Pranshu_Pandya</a> →\r\n <a href=\"/blog/entry/121171\">An Interesting Tree Problem</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/sszcdjr\" title=\"Master sszcdjr\" class=\"rated-user user-orange\">sszcdjr</a> →\r\n <a href=\"/blog/entry/119859\">Codeforces Round 896 (Div. 1, Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/119880\">It's Happening! Meta Hacker Cup 2023 Schedule</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/DaviddeGea1\" title=\"Expert DaviddeGea1\" class=\"rated-user user-blue\">DaviddeGea1</a> →\r\n <a href=\"/blog/entry/70917\">Number of ways of dividing an array into 2 parts such that sum of each part is > k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bekh\" title=\"Master Bekh\" class=\"rated-user user-orange\">Bekh</a> →\r\n <a href=\"/blog/entry/74245\">Questions and doubts regarding Aliens DP trick</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a> →\r\n <a href=\"/blog/entry/8192\">Codeforces Round #190 — Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/hocky\" title=\"Candidate Master hocky\" class=\"rated-user user-violet\">hocky</a> →\r\n <a href=\"/blog/entry/95323\">FBHC wuining uw Day? Incwease uw stacc size! (ㅅ´ ˘ `)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/liouzhou_101\" title=\"International Master liouzhou_101\" class=\"rated-user user-orange\">liouzhou_101</a> →\r\n <a href=\"/blog/entry/87598\">Editorial of Codeforces Round #700</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/yeon_gist\" title=\"Newbie yeon_gist\" class=\"rated-user user-gray\">yeon_gist</a> →\r\n <a href=\"/blog/entry/121170\">plusMinusPermutation computing error</a>\r\n <img alt=\"Text created or updated\" title=\"Text created or updated\" src=\"//codeforces.org/s/81027/images/icons/x-update-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/altforminuscontribution\" title=\"Newbie altforminuscontribution\" class=\"rated-user user-gray\">altforminuscontribution</a> →\r\n <a href=\"/blog/entry/121162\">My screen get unexpectedly big, what should I do</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/atcoder_official\" title=\"Unrated, atcoder_official\" class=\"rated-user user-black\">atcoder_official</a> →\r\n <a href=\"/blog/entry/121120\">We will hold UNIQUE VISION Programming Contest 2023 Autumn(AtCoder Beginner Contest 323)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/YouStill_DontKnowMeYet\" title=\"Candidate Master YouStill_DontKnowMeYet\" class=\"rated-user user-violet\">YouStill_DontKnowMeYet</a> →\r\n <a href=\"/blog/entry/117659\">[GYM] Al-Baath Collegiate Programming Contest 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/ankancool\" title=\"Expert ankancool\" class=\"rated-user user-blue\">ankancool</a> →\r\n <a href=\"/blog/entry/121136\">Invitation to AstroByte 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/GeZhiyuan\" title=\"Grandmaster GeZhiyuan\" class=\"rated-user user-red\">GeZhiyuan</a> →\r\n <a href=\"/blog/entry/120943\">Codeforces Round 901 (Div. 1, Div. 2) Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a> →\r\n <a href=\"/blog/entry/120772\">PSA: Increase your stack size before the Meta Hacker Cup, here's how</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/dino_merlin\" title=\"Expert dino_merlin\" class=\"rated-user user-blue\">dino_merlin</a> →\r\n <a href=\"/blog/entry/121145\">Intuitive approach for CEOI Kangaroo?</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/icecuber\" title=\"Grandmaster icecuber\" class=\"rated-user user-red\">icecuber</a> →\r\n <a href=\"/blog/entry/70018\">CSES DP section editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bn00b\" title=\"Newbie Bn00b\" class=\"rated-user user-gray\">Bn00b</a> →\r\n <a href=\"/blog/entry/98820\">[FEATURE REQUEST : ATCODER] TOPICS TAGS AND SORTING BY SOLVE COUNT</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a> →\r\n <a href=\"/blog/entry/121163\">AtCoder Regular Contest 166 Announcement</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/windva\" title=\"Grandmaster windva\" class=\"rated-user user-red\">windva</a> →\r\n <a href=\"/blog/entry/120644\">Codeforces Round 899 (Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Misa-Misa\" title=\"Expert Misa-Misa\" class=\"rated-user user-blue\">Misa-Misa</a> →\r\n <a href=\"/blog/entry/121157\">Someone please help me understand this.</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/shivam565\" title=\"Specialist shivam565\" class=\"rated-user user-cyan\">shivam565</a> →\r\n <a href=\"/blog/entry/108348\">Total number of subarrays with sum atmost k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n </ul>\r\n </div>\r\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/recent-actions\">Detailed →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n</div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li><a\r\n href=\"/profile/AkiLotus\">AkiLotus</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/AkiLotus\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/AkiLotus\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/AkiLotus\">Submissions</a></li>\r\n <li><a\r\n href=\"/groups/with/AkiLotus\">Groups</a></li>\r\n <li><a\r\n href=\"/contests/with/AkiLotus\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/AkiLotus\">Problemsetting</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/AkiLotus\" style=\"text-decoration:none;color:black !important;\">AkiLotus's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"64858\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/64453\"> <p>Codeforces Round #229 (Div. 2) Editorial [Unofficial]</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/AkiLotus\" title=\"Master AkiLotus\" class=\"rated-user user-orange\">AkiLotus</a>,\r\n <a href=\"/topic/64858/en4\">history</a>,\r\n <span class=\"format-humantime\" title=\"Jan/11/2019 15:40\">5 years ago</span>,\r\n \r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p><em>Since the original data has been lost during the dark days of Codeforces, no version of the editorial has been re-released, and I feel the round itself is quite educational, so I decided to give a try.</em></p><h2><a href=\"/contest/390/problem/A\" title=\"Codeforces Round 229 (Div. 2)\">390A - Инна и будильники</a></h2> <div class=\"spoiler\"><b class=\"spoiler-title\">Approach</b><div class=\"spoiler-content\" style=\"display: none;\"><p>The criterion shows that we can only use either vertical segments or horizontal segments.<br />Since there is no limit on the segments' length, we can see that it's always optimal to use a segment with infinite length (or may be known as a line).</p><p>We can see that the vertical line <span class=\"tex-span\"><i>x</i> = <i>a</i></span> will span through every alarm clocks standing at positions with x-coordinate being equal to <span class=\"tex-span\"><i>a</i></span>. In a similar manner, the horizontal line <span class=\"tex-span\"><i>y</i> = <i>b</i></span> will span through every alarm clocks standing at positions with y-coordinate being equal to <span class=\"tex-span\"><i>b</i></span>.</p><p>So, if we use vertical lines, the number of segments used will be the number of distinct values of x-coordinates found in the data. Similarly, the number of horizontal segments used will be the number of distinct values of y-coordinates found.</p><p>The process can be implemented by a counting array, or a map.</p><p>Time complexity: <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/e98e669660e295d23c96117b197140d3a3709707.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> for regular arrays, or <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/df2dace9ef526732e09735cc52a919faad47f167.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> for maps.</p></div></div> <div class=\"spoiler\"><b class=\"spoiler-title\">Solution 1 (Map)</b><div class=\"spoiler-content\" style=\"display: none;\"><p>Submission link: <a href=\"/contest/390/submission/48214007\" title=\"Посылка 48214007 от AkiLotus\">48214007</a></p> <div class=\"spoiler\"><b class=\"spoiler-title\">Source code in plain text</b><div class=\"spoiler-content\" style=\"display: none;\"><pre><code>#pragma GCC optimize("Ofast")\n\n#include <bits/stdc++.h>\nusing namespace std;\n\n#define endl '\\n'\nmt19937 rng32(chrono::steady_clock::now().time_since_epoch().count());\nmt19937_64 rng64(chrono::steady_clock::now().time_since_epoch().count());\n\nint main(int argc, char* argv[]) {\n\tios_base::sync_with_stdio(0); cin.tie(NULL);\n\t\n\tint n; cin >> n;\n\t\n\tmap<int, int> cntx, cnty;\n\t\n\twhile (n--) {\n\t\tint x, y;\n\t\tcin >> x >> y;\n\t\tcntx[x]++; cnty[y]++;\n\t}\n\t\n\tcout << min(cntx.size(), cnty.size()) << endl;\n\t\n\treturn 0;\n}\n</code></pre></div></div></div></div> <div class=\"spoiler\"><b class=\"spoiler-title\">Solution 2 (Array)</b><div class=\"spoiler-content\" style=\"display: none;\"><p>Submission link: <a href=\"/contest/390/submission/48213984\" title=\"Посылка 48213984 от AkiLotus\">48213984</a></p> <div class=\"spoiler\"><b class=\"spoiler-title\">Source code in plain text</b><div class=\"spoiler-content\" style=\"display: none;\"><pre><code>#pragma GCC optimize("Ofast")\n\n#include <bits/stdc++.h>\nusing namespace std;\n\n#define endl '\\n'\nmt19937 rng32(chrono::steady_clock::now().time_since_epoch().count());\nmt19937_64 rng64(chrono::steady_clock::now().time_since_epoch().count());\n\nint main(int argc, char* argv[]) {\n\tios_base::sync_with_stdio(0); cin.tie(NULL);\n\t\n\tint n; cin >> n;\n\t\n\tvector<int> cntx(101, 0);\n\tvector<int> cnty(101, 0);\n\t\n\twhile (n--) {\n\t\tint x, y;\n\t\tcin >> x >> y;\n\t\tcntx[x]++; cnty[y]++;\n\t}\n\t\n\tint distinctx = 0, distincty = 0;\n\tfor (int i=0; i<101; i++) {\n\t distinctx += (cntx[i] > 0);\n\t distincty += (cnty[i] > 0);\n\t}\n\t\n\tcout << min(distinctx, distincty) << endl;\n\t\n\treturn 0;\n}\n</code></pre></div></div></div></div><h2><a href=\"/contest/390/problem/B\" title=\"Codeforces Round 229 (Div. 2)\">390B - Инна, Дима и песня</a></h2> <div class=\"spoiler\"><b class=\"spoiler-title\">Approach</b><div class=\"spoiler-content\" style=\"display: none;\"><p>From the constraints given, for the <span class=\"tex-span\"><i>i</i></span>-th song, provided there exists corresponding <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span> and <span class=\"tex-span\"><i>y</i><sub class=\"lower-index\"><i>i</i></sub></span> values, then the following inequality must hold: <span class=\"tex-span\">2 ≤ <i>x</i><sub class=\"lower-index\"><i>i</i></sub> + <i>y</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 2·<i>a</i><sub class=\"lower-index\"><i>i</i></sub></span>.<br />Thus, if any <span class=\"tex-span\"><i>b</i><sub class=\"lower-index\"><i>i</i></sub></span> is either lower than <span class=\"tex-span\">2</span> or higher than <span class=\"tex-span\">2·<i>a</i><sub class=\"lower-index\"><i>i</i></sub></span>, then no <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span> and <span class=\"tex-span\"><i>y</i><sub class=\"lower-index\"><i>i</i></sub></span> can be found, thus, Sereja's joy will surely decrease by <span class=\"tex-span\">1</span>.</p><p>Amongst all pairs of <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/cb276cd4dc36f23b69b51abe41e17841282ed42c.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> that <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub> + <i>y</i><sub class=\"lower-index\"><i>i</i></sub> = <i>b</i><sub class=\"lower-index\"><i>i</i></sub></span>, the pair with the highest value of <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub>·<i>y</i><sub class=\"lower-index\"><i>i</i></sub></span> will be one with the equal value of <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub> = <i>y</i><sub class=\"lower-index\"><i>i</i></sub></span> (this can be proven by the famous AM-GM inequality).<br />Thus, if <span class=\"tex-span\"><i>b</i><sub class=\"lower-index\"><i>i</i></sub></span> is divisible by <span class=\"tex-span\">2</span>, we can easily pick <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/4ebbc716337dc5b987bc678f95685e3b6e874bfa.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />.<br />Also, from this, we can see (either intuitively or with static proofs) that the lower the difference between <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span> and <span class=\"tex-span\"><i>y</i><sub class=\"lower-index\"><i>i</i></sub></span> is, the higher the value <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub>·<i>y</i><sub class=\"lower-index\"><i>i</i></sub></span> will be. Thus, in case <span class=\"tex-span\"><i>b</i><sub class=\"lower-index\"><i>i</i></sub></span> being odd, the most optimal pair will be <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/4bc158af48fdad3d0dba7ead977ad08c6efd4343.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> or <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/443272cf5829fac4b5f9b1d92d3319449b0a967a.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> (the order doesn't matter here).</p><p>Time complexity: <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/e50d121c611e249696d85ac98167ee3dfa4ba3f3.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />.</p></div></div> <div class=\"spoiler\"><b class=\"spoiler-title\">Solution</b><div class=\"spoiler-content\" style=\"display: none;\"><p>Submission link: <a href=\"/contest/390/submission/48212208\" title=\"Посылка 48212208 от AkiLotus\">48212208</a></p> <div class=\"spoiler\"><b class=\"spoiler-title\">Source code in plain text</b><div class=\"spoiler-content\" style=\"display: none;\"><pre><code>#pragma GCC optimize("Ofast")\n\n#include <bits/stdc++.h>\nusing namespace std;\n\n#define endl '\\n'\nmt19937 rng32(chrono::steady_clock::now().time_since_epoch().count());\nmt19937_64 rng64(chrono::steady_clock::now().time_since_epoch().count());\n\nint main(int argc, char* argv[]) {\n\tios_base::sync_with_stdio(0); cin.tie(NULL);\n\t\n\tint n; cin >> n;\n\t\n\tvector<int> a(n), b(n);\n\tfor (auto &z: a) cin >> z;\n\tfor (auto &z: b) cin >> z;\n\t\n\tlong long Joy = 0;\n\tfor (int i=0; i<n; i++) {\n\t\tif (b[i] < 2 || b[i] > a[i] * 2) {Joy--; continue;}\n\t\tint x = b[i] / 2, y = b[i] - x;\n\t\tJoy += 1LL * x * y;\n\t}\n\tcout << Joy << endl;\n\t\n\treturn 0;\n}\n</code></pre></div></div></div></div><h2><a href=\"/contest/390/problem/C\" title=\"Codeforces Round 229 (Div. 2)\">390C - Инна и коробки с конфетами</a></h2> <div class=\"spoiler\"><b class=\"spoiler-title\">Approach</b><div class=\"spoiler-content\" style=\"display: none;\"><p>The query content looks pretty confusing at first, to be honest.<br />Since <span class=\"tex-span\"><i>k</i></span> is static throughout a scenario, we can group the boxes into <span class=\"tex-span\"><i>k</i></span> groups, the <span class=\"tex-span\"><i>z</i></span>-th box (in this editorial let's assume that the indices of the boxes start from <span class=\"tex-span\">0</span>) falls into group number <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/78bea9063020ea155fff32a481842014c32d98ba.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />.</p><p>Then, each query can be simplified as this: "Is that true that among the boxes with numbers from <span class=\"tex-span\"><i>l</i><sub class=\"lower-index\"><i>i</i></sub></span> to <span class=\"tex-span\"><i>r</i><sub class=\"lower-index\"><i>i</i></sub></span>, inclusive, the candies lie <strong>only</strong> in boxes of group <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/d252f9b61b64c0b830c9c0c1c3cda0fca9d00085.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />?</p><p>To make sure the answer for a query being "Yes", Dima has to remove candies from all candied-box in all groups other than <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/d252f9b61b64c0b830c9c0c1c3cda0fca9d00085.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />, while in that exact group, fill every empty box with a candy. Obviously, we'll consider boxes with indices between <span class=\"tex-span\"><i>l</i><sub class=\"lower-index\"><i>i</i></sub></span> and <span class=\"tex-span\"><i>r</i><sub class=\"lower-index\"><i>i</i></sub></span> inclusively only.</p><p>We can make <span class=\"tex-span\"><i>k</i></span> lists, the <span class=\"tex-span\"><i>t</i></span>-th (<span class=\"tex-span\">0</span>-indexed) list stores the indices of candied boxes in group <span class=\"tex-span\"><i>t</i></span>.</p><p>We'll process with each query as the following:</p> <ul> <li>Obviously, given from the criteria, each range will consist of exactly <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/830bdc9804371cb3a60ae9359bb9fe58149ae26d.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> boxes per each group. Let's denote <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/0220b561b0de8bb761315bed9f765526b1a82a12.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />.</li> <li>Traverse all groups, for the <span class=\"tex-span\"><i>t</i></span>-th group (again, <span class=\"tex-span\">0</span>-indexed), let's denote <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>t</i></sub></span> as the number of candied boxes of group <span class=\"tex-span\"><i>t</i></span> in the given range. This value can be calculated quickly through binary searching the constructed lists above.</li> <li>If group <span class=\"tex-span\"><i>t</i></span> is not the group being demanded to have candies (group <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/d252f9b61b64c0b830c9c0c1c3cda0fca9d00085.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />), we'll need to perform <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>t</i></sub></span> actions (removing candies). Otherwise, we'll need to perform <span class=\"tex-span\"><i>A</i> - <i>x</i><sub class=\"lower-index\"><i>t</i></sub></span> actions (adding candies to empty boxes).</li> </ul><p>Time complexity: <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/83fab29132fa3970fad25e1e222dfe177167bae6.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />.</p></div></div> <div class=\"spoiler\"><b class=\"spoiler-title\">Solution</b><div class=\"spoiler-content\" style=\"display: none;\"><p>Submission link: <a href=\"/contest/390/submission/48213932\" title=\"Посылка 48213932 от AkiLotus\">48213932</a></p> <div class=\"spoiler\"><b class=\"spoiler-title\">Source code in plain text</b><div class=\"spoiler-content\" style=\"display: none;\"><pre><code>#pragma GCC optimize("Ofast")\n\n#include <bits/stdc++.h>\nusing namespace std;\n\n#define endl '\\n'\nmt19937 rng32(chrono::steady_clock::now().time_since_epoch().count());\nmt19937_64 rng64(chrono::steady_clock::now().time_since_epoch().count());\n\nint main(int argc, char* argv[]) {\n\tios_base::sync_with_stdio(0); cin.tie(NULL);\n\t\n\tint n, k, w; string s;\n\tcin >> n >> k >> w >> s;\n\t\n\tvector< vector<int> > CandyGrp(k);\n\t\n\tfor (int i=0; i<n; i++) {\n\t if (s[i] == '0') continue;\n\t CandyGrp[i % k].push_back(i);\n\t}\n\t\n\twhile (w--) {\n\t int l, r;\n\t\tcin >> l >> r; l--; r--;\n\t\t\n\t\tint res = 0;\n\t\tint demandedGroup = (l + k - 1) % k;\n\t\tint BoxesPerGroup = (r - l + 1) / k;\n\t\t\n\t\tfor (int id=0; id<k; id++) {\n\t\t \n\t\t\tint x = lower_bound(CandyGrp[id].begin(), CandyGrp[id].end(), l) - CandyGrp[id].begin();\n\t\t\tint y = upper_bound(CandyGrp[id].begin(), CandyGrp[id].end(), r) - CandyGrp[id].begin();\n\t\t\t\n\t\t\tif (id == demandedGroup) {\n\t\t\t res += (BoxesPerGroup - (y - x));\n\t\t\t}\n\t\t\telse res += (y - x);\n\t\t}\n\t\t\n\t\tcout << res << endl;\n\t}\n\t\n\treturn 0;\n}\n</code></pre></div></div></div></div><h2><a href=\"/contest/390/problem/D\" title=\"Codeforces Round 229 (Div. 2)\">390D - Инна и матрица конфет</a></h2> <div class=\"spoiler\"><b class=\"spoiler-title\">Approach</b><div class=\"spoiler-content\" style=\"display: none;\"><p>We can see that the most optimal placement will be choosing <span class=\"tex-span\"><i>k</i></span> cells being nearest to cell <span class=\"tex-span\">(1, 1)</span> (yup, including <span class=\"tex-span\">(1, 1)</span> itself).<br />To find these <span class=\"tex-span\"><i>k</i></span> points, we can simply do a BFS starting from <span class=\"tex-span\">(1, 1)</span>, with traceback feature to construct the paths to get to those cells.<br />However, keep in mind that any cell being candied will later on become obstacles for the following paths. Thus, to avoid blocking yourself, you should transfer candies to the farthest cells first, then getting closer. Thus, cell <span class=\"tex-span\">(1, 1)</span> will be the last one being filled with candy.</p><p>Time complexity: <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/464cbb240e8ae8db0420805250b0ac00f29c8f7b.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> or <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/be7d2fc31b8207bf6178bb14a23b362773fd4c75.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />, based on implementation (I myself did <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/be7d2fc31b8207bf6178bb14a23b362773fd4c75.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />, since the difference isn't too much).</p></div></div> <div class=\"spoiler\"><b class=\"spoiler-title\">Solution</b><div class=\"spoiler-content\" style=\"display: none;\"><p>Submission link: <a href=\"/contest/390/submission/48213856\" title=\"Посылка 48213856 от AkiLotus\">48213856</a></p> <div class=\"spoiler\"><b class=\"spoiler-title\">Source code in plain text</b><div class=\"spoiler-content\" style=\"display: none;\"><pre><code>#pragma GCC optimize("Ofast")\n\n#include <bits/stdc++.h>\nusing namespace std;\n\n#define endl '\\n'\nmt19937 rng32(chrono::steady_clock::now().time_since_epoch().count());\nmt19937_64 rng64(chrono::steady_clock::now().time_since_epoch().count());\n\nint dx[] = {-1, +0, +0, +1};\nint dy[] = {+0, -1, +1, +0};\npair<int, int> Default = {-1, -1};\n\nint main(int argc, char* argv[]) {\n\tios_base::sync_with_stdio(0); cin.tie(NULL);\n\t\n\tint n, m, k; cin >> n >> m >> k;\n\t\n\tvector<vector<int>> Dist(n+2, vector<int>(m+2, 4444));\n\tvector<vector<pair<int, int>>> Last(n+2, vector<pair<int, int>>(m+2, Default));\n \n\tstack<pair<int, int>> Cells;\n\tint cost = 0;\n\t\n\tqueue<pair<int, int>> Q;\n\tQ.push({1, 1}); Dist[1][1] = 1;\n\t\n\twhile (!Q.empty() && Cells.size() < k) {\n\t\tpair<int, int> C = Q.front(); Q.pop();\n\t\tCells.push(C); int x = C.first, y = C.second;\n\t\t\n\t\tcost += Dist[x][y];\n\t\t\n\t\tfor (int dir=0; dir<4; dir++) {\n\t\t\tif (x + dx[dir] < 1 || x + dx[dir] > n) continue;\n\t\t\tif (y + dy[dir] < 1 || y + dy[dir] > m) continue;\n\t\t\t\n\t\t\tif (Dist[x+dx[dir]][y+dy[dir]] != 4444) continue;\n\t\t\t\n\t\t\tDist[x+dx[dir]][y+dy[dir]] = Dist[x][y] + 1;\n\t\t\tQ.push({x + dx[dir], y + dy[dir]});\n\t\t\tLast[x+dx[dir]][y+dy[dir]] = C;\n\t\t}\n\t}\n\t\n\tcout << cost << endl;\n\t\n\twhile (!Cells.empty()) {\n\t\tint x = Cells.top().first, y = Cells.top().second; Cells.pop();\n\t\tstack<pair<int, int>> Traceback;\n\t\t\n\t\twhile (x != -1 && y != -1) {\n\t\t\tTraceback.push({x, y});\n\t\t\tpair<int, int> NextCell = Last[x][y];\n\t\t\tx = NextCell.first; y = NextCell.second;\n\t\t}\n\t\t\n\t\twhile (!Traceback.empty()) {\n\t\t\tpair<int, int> CurCell = Traceback.top();\n\t\t\tTraceback.pop();\n\t\t\tcout << "(" << CurCell.first << ", " << CurCell.second << ") ";\n\t\t}\n\t\tcout << endl;\n\t}\n\t\n\treturn 0;\n}\n</code></pre></div></div></div></div><h2><a href=\"/contest/390/problem/E\" title=\"Codeforces Round 229 (Div. 2)\">390E - Инна и большая матрица конфет</a></h2> <div class=\"spoiler\"><b class=\"spoiler-title\">Approach</b><div class=\"spoiler-content\" style=\"display: none;\"><p>Let's denote <span class=\"tex-span\"><i>A</i></span> as the total number of candies on the board, <span class=\"tex-span\"><i>R</i><sub class=\"lower-index\"><i>i</i></sub></span> as the total number of candies on the <span class=\"tex-span\"><i>i</i></span>-th row (<span class=\"tex-span\">1 ≤ <i>i</i> ≤ <i>n</i></span>), <span class=\"tex-span\"><i>C</i><sub class=\"lower-index\"><i>j</i></sub></span> as the total number of candies on the <span class=\"tex-span\"><i>j</i></span>-th column (<span class=\"tex-span\">1 ≤ <i>j</i> ≤ <i>m</i></span>).</p><p>Also, let's denote <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/b38d7b9a33912f8ddf2960acee5927b6bfd14cb9.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> and <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/01d697cc3de45d71c1ae7efa08207ea0fbe4c73b.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />.</p><p>Let's considered the 2nd type of query first. Denoting the answer for the query as <span class=\"tex-span\"><i>f</i>(<i>x</i><sub class=\"lower-index\">1</sub>, <i>y</i><sub class=\"lower-index\">1</sub>, <i>x</i><sub class=\"lower-index\">2</sub>, <i>y</i><sub class=\"lower-index\">2</sub>)</span>, we can see that <span class=\"tex-span\"><i>f</i>(<i>x</i><sub class=\"lower-index\">1</sub>, <i>y</i><sub class=\"lower-index\">1</sub>, <i>x</i><sub class=\"lower-index\">2</sub>, <i>y</i><sub class=\"lower-index\">2</sub>) = <i>R</i>(<i>x</i><sub class=\"lower-index\">1</sub>, <i>x</i><sub class=\"lower-index\">2</sub>) + <i>C</i>(<i>y</i><sub class=\"lower-index\">1</sub>, <i>y</i><sub class=\"lower-index\">2</sub>) - <i>A</i></span> (you can draw a simple diagram and validate this function).</p><p>Thus, the problem is now reduced to calculating <span class=\"tex-span\"><i>R</i>(<i>x</i><sub class=\"lower-index\">1</sub>, <i>x</i><sub class=\"lower-index\">2</sub>)</span>, <span class=\"tex-span\"><i>C</i>(<i>y</i><sub class=\"lower-index\">1</sub>, <i>y</i><sub class=\"lower-index\">2</sub>)</span> and <span class=\"tex-span\"><i>A</i></span>:</p> <ul> <li><span class=\"tex-span\"><i>A</i></span> can be easily calculated. After each query of the 1st type with parameters <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">1</sub></span>, <span class=\"tex-span\"><i>y</i><sub class=\"lower-index\">1</sub></span>, <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">2</sub></span>, <span class=\"tex-span\"><i>y</i><sub class=\"lower-index\">2</sub></span>, <span class=\"tex-span\"><i>v</i></span>; <span class=\"tex-span\"><i>A</i></span> will be increased by <span class=\"tex-span\"><i>v</i>·(<i>x</i><sub class=\"lower-index\">2</sub> - <i>x</i><sub class=\"lower-index\">1</sub> + 1)·(<i>y</i><sub class=\"lower-index\">2</sub> - <i>y</i><sub class=\"lower-index\">1</sub> + 1)</span>.</li> <li>The calculation of <span class=\"tex-span\"><i>R</i>(<i>x</i><sub class=\"lower-index\">1</sub>, <i>x</i><sub class=\"lower-index\">2</sub>)</span> and <span class=\"tex-span\"><i>C</i>(<i>y</i><sub class=\"lower-index\">1</sub>, <i>y</i><sub class=\"lower-index\">2</sub>)</span> makes us thinking about some kinds of data structures that support range sum update and range sum query. Segment trees and Fenwick trees can both work on that. Personally I used segment trees, they fit in just right for the memory limit (I implemented it by vectors, regular arrays will obviously be safer).</li> </ul><p>Time complexity: <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/88dba0191e24dada9126d8d5b164d4ade4f556d6.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />.</p></div></div> <div class=\"spoiler\"><b class=\"spoiler-title\">Solution</b><div class=\"spoiler-content\" style=\"display: none;\"><p>Submission link: <a href=\"/contest/390/submission/48213830\" title=\"Посылка 48213830 от AkiLotus\">48213830</a></p> <div class=\"spoiler\"><b class=\"spoiler-title\">Source code in plain text</b><div class=\"spoiler-content\" style=\"display: none;\"><pre><code>#pragma GCC optimize("Ofast")\n\n#include <bits/stdc++.h>\nusing namespace std;\n\n#define endl '\\n'\nmt19937 rng32(chrono::steady_clock::now().time_since_epoch().count());\nmt19937_64 rng64(chrono::steady_clock::now().time_since_epoch().count());\n\nstruct SegTree_Sum {\n\tint n; vector<long long> Tree, Lazy;\n\tSegTree_Sum() {}\n\tSegTree_Sum(int _n) {\n\t\tn = _n;\n\t\tTree.resize(n*4);\n\t\tLazy.resize(n*4);\n\t}\n\t\n\tvoid Propagate(int node, int st, int en) {\n\t\tif (Lazy[node] == 0) return;\n\t\tTree[node] += Lazy[node] * (en - st + 1);\n\t\tif (st != en) {\n\t\t\tLazy[node*2+1] += Lazy[node];\n\t\t\tLazy[node*2+2] += Lazy[node];\n\t\t}\n\t\tLazy[node] = 0;\n\t}\n\t\n\tvoid Update(int node, int st, int en, int L, int R, long long val) {\n\t\tPropagate(node, st, en);\n\t\tif (en < st || R < st || en < L) return;\n\t\tif (L <= st && en <= R) {\n\t\t\tLazy[node] += val;\n\t\t\tPropagate(node, st, en); return;\n\t\t}\n\t\tUpdate(node*2+1, st, (st+en)/2+0, L, R, val);\n\t\tUpdate(node*2+2, (st+en)/2+1, en, L, R, val);\n\t\tTree[node] = Tree[node*2+1] + Tree[node*2+2];\n\t}\n\t\n\tlong long Sum(int node, int st, int en, int L, int R) {\n\t\tPropagate(node, st, en);\n\t\tif (en < st || R < st || en < L) return 0LL;\n\t\tif (L <= st && en <= R) return Tree[node];\n\t\tlong long p1 = Sum(node*2+1, st, (st+en)/2+0, L, R);\n\t\tlong long p2 = Sum(node*2+2, (st+en)/2+1, en, L, R);\n\t\treturn (p1 + p2);\n\t}\n\t\n\tvoid RangeUpdate(int L, int R, long long val) {\n\t\tUpdate(0, 0, n-1, L, R, val);\n\t}\n\t\n\tlong long RangeSum(int L, int R) {\n\t\treturn Sum(0, 0, n-1, L, R);\n\t}\n};\n\nint main(int argc, char* argv[]) {\n\tios_base::sync_with_stdio(0); cin.tie(NULL);\n\t\n\tint n, m, w; cin >> n >> m >> w;\n\t\n\tlong long TotalCandies = 0;\n\t\n\tSegTree_Sum TreeRow = SegTree_Sum(n);\n\tSegTree_Sum TreeCol = SegTree_Sum(m);\n\t\n\twhile (w--) {\n\t\tint t, x1, y1, x2, y2;\n\t\tcin >> t >> x1 >> y1 >> x2 >> y2;\n\t\t\n\t\tif (t == 0) {\n\t\t\tint v; cin >> v;\n\t\t\t\n\t\t\tTotalCandies += 1LL * (x2 - x1 + 1) * (y2 - y1 + 1) * v;\n\t\t\t\n\t\t\tTreeRow.RangeUpdate(x1, x2, 1LL * v * (y2 - y1 + 1));\n\t\t\tTreeCol.RangeUpdate(y1, y2, 1LL * v * (x2 - x1 + 1));\n\t\t}\n\t\telse if (t == 1) {\n\t\t\tlong long res = 0;\n\t\t\t\n\t\t\tres += TreeRow.RangeSum(x1, x2);\n\t\t\tres += TreeCol.RangeSum(y1, y2);\n\t\t\tres -= TotalCandies;\n\t\t\t\n\t\t\tcout << res << endl;\n\t\t}\n\t}\n\t\n\treturn 0;\n}\n</code></pre></div></div></div></div></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/390\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 229 (Div. 2)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-87995-64858\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"87995\",\n blogEntryId: \"64453\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n <div style=\"font-size: 1.1rem;line-height: 11px;\">\r\n <img style=\"vertical-align: middle;\" src=\"//codeforces.org/s/81027/images/blog/tags.png\" title=\"Tags\" alt=\"Tags\"/>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=codeforces\" class=\"tag notice\" style=\"text-decoration: none;\">codeforces</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=229\" class=\"tag notice\" style=\"text-decoration: none;\">229</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=editorial\" class=\"tag notice\" style=\"text-decoration: none;\">editorial</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=second+division\" class=\"tag notice\" style=\"text-decoration: none;\">second division</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=unofficial\" class=\"tag notice\" style=\"text-decoration: none;\">unofficial</a>\r\n </span>\r\n </div>\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-64858\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+37</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-64858\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/AkiLotus\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/AkiLotus\">\n AkiLotus\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Jan/11/2019 15:40\">5 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/64453#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/64453#comments\">\n 7\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"67789\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (7)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"483591\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/stringray\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/575608/avatar/2902babcf56868a2.jpg'/> </a>\n <div><a href=\"/profile/stringray\" title=\"Expert stringray\" class=\"rated-user user-blue\">stringray</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/11/2019 16:50\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-483591\" href=\"?#comment-483591\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"483591\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"575608\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-483591\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>thanks.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-483591 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-483591 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-483591\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"483886\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/caojiangxia\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/374616/avatar/c98eb6a36d8f2853.jpg'/> </a>\n <div><a href=\"/profile/caojiangxia\" title=\"Expert caojiangxia\" class=\"rated-user user-blue\">caojiangxia</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/12/2019 08:51\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-483886\" href=\"?#comment-483886\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"483886\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"374616\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-483886\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Good Job</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-483886 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-483886 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-483886\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"484101\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/MaliceX\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/763085/avatar/45ebf84daf0a0fb6.jpg'/> </a>\n <div><a href=\"/profile/MaliceX\" title=\"Candidate Master MaliceX\" class=\"rated-user user-violet\">MaliceX</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/12/2019 18:35\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-484101\" href=\"?#comment-484101\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"484101\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"11\"\r\n data-commentUserId=\"763085\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+11</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-484101\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Already the account with most ACs in the country, what a hard-working person!</p><p>Did you find this contest by accident or have you done it all the way back there ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-484101 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-484101 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-484101\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"484104\" commentParentId=\"484101\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/AkiLotus\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/562732/avatar/374a86575dcbea6a.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/AkiLotus\" title=\"Master AkiLotus\" class=\"rated-user user-orange\">AkiLotus</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/12/2019 18:36\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-484104\" href=\"?#comment-484104\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-484101\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"484104\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"13\"\r\n data-commentUserId=\"562732\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+13</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-484104\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I just came across it while searching for some relaxing undone contest to do virtual, then I found this :D</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-484104 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-484104 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-484104\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"484114\" commentParentId=\"484104\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/MaliceX\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/763085/avatar/45ebf84daf0a0fb6.jpg'/> </a>\n <div><a href=\"/profile/MaliceX\" title=\"Candidate Master MaliceX\" class=\"rated-user user-violet\">MaliceX</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/12/2019 19:01\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-484114\" href=\"?#comment-484114\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-484104\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"484114\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"763085\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-484114\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>What is your motivation to train so hard ? I want to be as good as you are, but I'm so lazy xD</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-484114 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-484114 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-484114\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"484116\" commentParentId=\"484114\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/AkiLotus\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/562732/avatar/374a86575dcbea6a.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/AkiLotus\" title=\"Master AkiLotus\" class=\"rated-user user-orange\">AkiLotus</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/12/2019 19:04\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-484116\" href=\"?#comment-484116\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-484114\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"484116\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"13\"\r\n data-commentUserId=\"562732\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+13</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-484116\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I'm quite of a guy with innate self-motivating ability :D</p><p>Also, tbh, I have only stepped into CP since college, which is way late compared to many other guys. To fill the gap, guess I have no better choice but double my efforts ;)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-484116 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-484116 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-484116\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"486236\" commentParentId=\"484116\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/SonDinh\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/722820/avatar/14ca0ac05fda3ca0.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/SonDinh\" title=\"Expert SonDinh\" class=\"rated-user user-blue\">SonDinh</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/22/2019 17:13\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-486236\" href=\"?#comment-486236\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-484116\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"486236\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"722820\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-486236\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I really admire you, how much time do you spend a day to practise CP?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-486236 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-486236 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-486236\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n <br/>\r\n\r\n<div id=\"editBox-67789\" style=\"width:50em;display:none;\">\r\n <div class=\"previewBody\" style=\"border: 1px solid #d4d4d4; margin-bottom: 0.5em; padding: 0.25em; display:none;\"> </div>\r\n <div style=\"width: 1px\"> </div>\r\n <div class=\"commentLocale\" style=\"position: relative; top: 0.5em;left:4px;display: none;\">\r\n <input type=\"radio\" name=\"locale\" value=\"en\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In English</span>\r\n <input style=\"margin-left:1em\" type=\"radio\" name=\"locale\" value=\"ru\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In Russian</span>\r\n </div>\r\n <textarea data-drafts-id=\"CommentReplyFrame\" class=\"wysiwyg\" name=\"editContent\" rows=\"20\" style=\"width:99%;\"></textarea>\r\n <div class=\"error error__content\"></div>\r\n <div style=\"text-align:center;\">\r\n <input type=\"button\" name=\"preview\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Preview\"/>\r\n <input type=\"button\" name=\"save\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Save\"/>\r\n </div>\r\n</div>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n\r\nvar firstPreview67789 = true;\r\nvar lastPreviewContent67789 = '';\r\n\r\nif (!window.moveCommentRevision) {\r\n moveCommentRevision = function(e, dir) {\r\n var p = e.parent();\r\n var revisionCount = parseInt(p.attr(\"revisionCount\"));\r\n var revision = parseInt(p.attr(\"revision\"));\r\n var next = revision + dir;\r\n var commentId = p.attr(\"commentId\");\r\n if (next >= 1 && next <= revisionCount) {\r\n $.post(\r\n \"/data/comment-data\",\r\n {action: \"revision\", commentId: commentId, revision: next},\r\n function(json) {\r\n if (json.success == \"true\") {\r\n var parentDiv = e;\r\n\r\n while (parentDiv !== null && (parentDiv[0].nodeName.toLowerCase() !== \"td\" || !parentDiv.hasClass(\"right\"))) {\r\n parentDiv = parentDiv.parent();\r\n }\r\n\r\n if (parentDiv === null) {\r\n return;\r\n }\r\n\r\n parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\").html(json.content);\r\n Codeforces.setupSpoilers(parentDiv.find(\"div.comment-content-\" + commentId + \" .moveup\"));\r\n p.attr(\"revision\", next);\r\n p.find(\"span.revision\").text(next);\r\n if (next == 1) {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.leftRevision\").css(\"visibility\", \"visible\");\r\n }\r\n if (next == revisionCount) {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"hidden\");\r\n } else {\r\n p.find(\"a.rightRevision\").css(\"visibility\", \"visible\");\r\n }\r\n\r\n window.updateTypography();\r\n MathJax.Hub.Typeset();\r\n } else {\r\n alert(e.error);\r\n }\r\n },\r\n \"json\"\r\n );\r\n }\r\n };\r\n}\r\n\r\n$(\"div[commentableId=67789] a.leftRevision\").click(function () {\r\n window.moveCommentRevision($(this), -1);\r\n return false;\r\n});\r\n\r\n$(\"div[commentableId=67789] a.rightRevision\").click(function () {\r\n window.moveCommentRevision($(this), +1);\r\n return false;\r\n});\r\n\r\n\r\n\r\n });\n </script>\n\r\n\r\n <script src=\"//codeforces.org/s/81027/js/swfobject-2.2.min.js\" type=\"text/javascript\"></script>\n <script src=\"//codeforces.org/s/81027/js/ftaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n if (window.evercookie) {\n var ec = new evercookie({\n history: false,\n silverlight: false,\n baseurl: '',\n asseturi: '/assets',\n phpuri: '/2fdcd78',\n pngPath: '/eps',\n etagPath: '/ees',\n cachePath: '/ecs'\n });\n\n var randomNumber = function () {\n return Math.random().toString(36).substr(2);\n };\n\n var randomToken = function () {\n return (randomNumber() + randomNumber()).substring(0, 18);\n };\n\n window._ftaa = \"\";\n\n ec.get(\"70a7c28f3de\", function (value) {\n window._ftaa = value;\n if (!window._ftaa) {\n window._ftaa = randomToken();\n ec.set(\"70a7c28f3de\", window._ftaa);\n }\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n } else {\n window._ftaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\n <script src=\"//codeforces.org/s/81027/js/bfaa.js\" type=\"text/javascript\"></script>\n <script type=\"text/javascript\">\n $(function() {\n var fpCallback = function() {\n Fingerprint2.get({}, function(components) {\n window._bfaa = Fingerprint2.x64hash128(components.map(function (pair) { return pair.value }).join(), 31);\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n });\n };\n if (typeof Fingerprint2 !== 'undefined') {\n if (window.requestIdleCallback) {\n requestIdleCallback(fpCallback)\n } else {\n setTimeout(fpCallback, 500)\n }\n } else {\n window._bfaa = \"n/a\";\n $.post(\"/data/empty\", {bfaa: window._bfaa, ftaa: window._ftaa});\n }\n });\n </script>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"a.new-root-comment\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n\r\n $(\".comment-table .reply a\").click(function () {\r\n window.location = \"/enter\";\r\n return false;\r\n });\r\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".vote-for-comment\").mouseover(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.find(\"img\").attr(\"popacity\", vote.find(\"img\").css(\"opacity\"));\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").mouseout(function () {\r\n var vote = $(this);\r\n var direction = vote.attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n if (direction == 1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n if (direction == -1 && !ownComment) {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\");\r\n vote.find(\"img\").css(\"opacity\", vote.find(\"img\").attr(\"popacity\"));\r\n }\r\n });\r\n\r\n $(\".vote-for-comment\").click(function () {\r\n var vote = $(this);\r\n var commentId = $(this).parent().attr(\"commentid\");\r\n var commentRating = $(this).parent().attr(\"data-commentRating\");\r\n var direction = $(this).attr(\"voteDirection\");\r\n var commentUserId = $(this).parent().attr(\"data-commentUserId\");\r\n var ownComment = false;\r\n $.post(\"/data/comment/vote\", {commentId: commentId, _tta: Codeforces.tta(), vote: direction, commentRating: commentRating}, function(data) {\r\n if (direction != 0 && !ownComment && data[\"success\"] == \"true\") {\r\n vote.parent().find(\".vote-for-comment\").attr(\"voteDirection\", 0);\r\n if (direction == 1)\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-voteup.png\");\r\n else {\r\n vote.find(\"img\").attr(\"src\", \"//codeforces.org/s/81027/images/actions/comment-votedown.png\");\r\n vote.closest(\".CommentVoteFrame\").find(\".ComplaintFrame\").css(\"display\", \"inline-block\");\r\n }\r\n vote.find(\"img\").attr(\"popacity\", \"1.0\");\r\n vote.find(\"img\").css(\"opacity\", \"1.0\");\r\n vote.parent().find(\".commentRating\").html(data[\"commentRating\"]);\r\n }\r\n Codeforces.showMessage(data[\"message\"]);\r\n }, \"json\");\r\n return false;\r\n });\r\n\r\n $(\".negative-comment-vote\").closest(\".comment-table\").addClass(\"comment-bad\");\r\n\r\n $(\".troll-comment-vote\").closest(\".comment\").css(\"display\", \"none\");\r\n\r\n $(\".too-negative-comment-vote\").closest(\".comment-table\").each(function () {\r\n var e = $(this);\r\n e.addClass(\"comment-too-bad\");\r\n var commentId = e.attr(\"commentId\");\r\n $(\"<div class='bad-comment-replacement ttypography'>The comment is hidden because of too negative feedback, click <a href=# class=show-bad-comment-link>here</a> to view it</div>\").appendTo(\r\n e.find(\".right\")\r\n );\r\n e.find(\".comment-content\").hide();\r\n e.find(\".show-bad-comment-link\").click(function () {\r\n e.find(\".comment-content\").show();\r\n e.find(\".bad-comment-replacement\").hide();\r\n return false;\r\n });\r\n });\r\n });\n </script>\n </div>\r\n\r\n <style type=\"text/css\">\r\n .new-comments-box {\r\n padding: 0.5em;\r\n width: 22px;\r\n font-size: 1.3rem;\r\n font-weight: bold !important;\r\n\r\n position: fixed;\r\n top: 40%;\r\n right: 0;\r\n opacity: 0.2;\r\n color: white;\r\n text-align: center;\r\n\r\n border: 1px solid #222;\r\n background-color: #888 !important;\r\n border-radius: 3px;\r\n -moz-border-radius: 3px;\r\n -webkit-border-radius: 3px;\r\n }\r\n\r\n .new-comments-box:hover {\r\n opacity: 1;\r\n }\r\n\r\n .new-comments-box .dir:hover {\r\n background: #3B5998 !important;\r\n cursor: pointer;\r\n }\r\n </style>\r\n\r\n <div class=\"new-comments-box\" data-position=\"outside\" data-index=\"-1\" style=\"display: none;\">\r\n <div class=\"up dir\" title=\"Ctrl+Up\">↑<hr/>\r\n </div>\r\n <div class=\"info\" title=\"New comments\"></div>\r\n <div class=\"down dir\" title=\"Ctrl+Down\">\r\n <hr/>↓\r\n </div>\r\n </div>\r\n\r\n <script>\r\n $(\".show-archived-checkbox\").change(function () {\r\n const checked = $(this).is(\":checked\");\r\n $.post(\"/data/comment-data\", {action: \"setShowArchived\", checked}, function (json) {\r\n if (json[\"success\"] !== \"true\") {\r\n alert(json[\"error\"]);\r\n } else {\r\n if (checked) {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are now displayed\")\r\n } else {\r\n Codeforces.reloadAndShowMessage(\"Archived comments are no longer displayed\")\r\n }\r\n }\r\n });\r\n return false;\r\n });\r\n\r\n function gotoComment(direction) {\r\n var box = $(\".new-comments-box\");\r\n var index = parseInt(box.attr(\"data-index\"));\r\n if (index == -1)\r\n index = 0;\r\n else\r\n index = Math.max(0, Math.min(parseInt(box.find(\".info\").text()) - 1, index + direction));\r\n box.attr(\"data-index\", index);\r\n var comment = $($(\".comment .highlight-blue[commentId]\").get(index));\r\n $('html, body').animate({\r\n 'scrollTop': Math.max(0, comment.offset().top - ($(window).height() - comment.height()) / 2)\r\n });\r\n return false;\r\n }\r\n\r\n $(\".new-comments-box .down\").click(function () {\r\n return gotoComment(1);\r\n });\r\n\r\n $(\".new-comments-box .up\").click(function () {\r\n return gotoComment(-1);\r\n });\r\n\r\n $(document).keydown(function (e) {\r\n var code = (e.keyCode ? e.keyCode : e.which);\r\n if (e.ctrlKey) {\r\n if (code == 38 || code == 40) {\r\n gotoComment(code - 39);\r\n }\r\n }\r\n });\r\n\r\n var newCommentCount = $(\".comment .highlight-blue[commentId]\").length;\r\n if (newCommentCount > 0) {\r\n $(\".new-comments-box .info\").text(newCommentCount);\r\n $(\".new-comments-box\").show();\r\n }\r\n\r\n $('table.comment-table').mouseenter(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").addClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n\r\n $('table.comment-table').mouseleave(function () {\r\n var comment = $(this);\r\n var cnt = 0;\r\n while (true) {\r\n var id = comment.attr(\"commentId\");\r\n var parentId = comment.attr(\"commentParentId\");\r\n comment.find(\".comment-indent-holder:first .comment-no-indent\").removeClass(\"comment-indent\");\r\n if (parentId == -1) {\r\n break;\r\n }\r\n comment = $(\"table.comment-table[commentId=\" + parentId + \"]\");\r\n }\r\n return false;\r\n });\r\n </script>\r\n\r\n\r\n\r\n <script>\r\n function adjustTopicComplainFrames() {\r\n let topicIds = [];\r\n\r\n $(\".has-topic-id\").each(function () {\r\n const $this = $(this);\r\n const topicId = $this.attr(\"topicId\");\r\n if (topicId) {\r\n topicIds.push(topicId);\r\n }\r\n });\r\n\r\n $.post(\"/data/topics\", {\r\n action: \"findComplainableTopicIds\",\r\n topicIds: topicIds.join(\",\")\r\n }, function (json) {\r\n if (json[\"success\"] === \"true\") {\r\n for (const topicId of json[\"complainableTopicIds\"].split(\",\")) {\r\n $(\".has-topic-id[topicId=\" + topicId + \"]\").each(function () {\r\n $(this).find(\".meta .ComplaintFrame\").css(\"display\", \"inline-block\");\r\n });\r\n }\r\n }\r\n }, \"json\");\r\n }\r\n\r\n $(function () {\r\n adjustTopicComplainFrames();\r\n })\r\n </script>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-64858\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 64858, _tta: Codeforces.tta(), topicRevisionId: 152874, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-64858\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 64858, _tta: Codeforces.tta(), topicRevisionId: 152874, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n </div>\r\n </div>\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 22:13:08</span> (h1).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/81027/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/81027/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/81027/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/81027/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-81027.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'812875abea0b9d76',t:'MTY5NjcwNTk4OC41NjQwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"}}},{"rowIdx":1970,"cells":{"problem_id":{"kind":"string","value":"390C"},"contest":{"kind":"string","value":"390"},"problem":{"kind":"string","value":"C"},"lang":{"kind":"string","value":"en"},"problem_title":{"kind":"string","value":"C. Inna and Candy Boxes"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">C. Inna and Candy Boxes</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Inna loves sweets very much. She has <span class=\"tex-span\"><i>n</i></span> closed present boxes lines up in a row in front of her. Each of these boxes contains either a candy (Dima's work) or nothing (Sereja's work). Let's assume that the boxes are numbered from 1 to <span class=\"tex-span\"><i>n</i></span>, from left to right.</p><p>As the boxes are closed, Inna doesn't know which boxes contain candies and which boxes contain nothing. Inna chose number <span class=\"tex-span\"><i>k</i></span> and asked <span class=\"tex-span\"><i>w</i></span> questions to Dima to find that out. Each question is characterised by two integers <span class=\"tex-span\"><i>l</i><sub class=\"lower-index\"><i>i</i></sub>, <i>r</i><sub class=\"lower-index\"><i>i</i></sub></span> (<span class=\"tex-span\">1 ≤ <i>l</i><sub class=\"lower-index\"><i>i</i></sub> ≤ <i>r</i><sub class=\"lower-index\"><i>i</i></sub> ≤ <i>n</i></span>; <span class=\"tex-span\"><i>r</i> - <i>l</i> + 1</span> is divisible by <span class=\"tex-span\"><i>k</i></span>), the <span class=\"tex-span\"><i>i</i></span>-th question is: \"Dima, is that true that among the boxes with numbers from <span class=\"tex-span\"><i>l</i><sub class=\"lower-index\"><i>i</i></sub></span> to <span class=\"tex-span\"><i>r</i><sub class=\"lower-index\"><i>i</i></sub></span>, inclusive, the candies lie <span class=\"tex-font-style-bf\">only</span> in boxes with numbers <span class=\"tex-span\"><i>l</i><sub class=\"lower-index\"><i>i</i></sub> + <i>k</i> - 1</span>, <span class=\"tex-span\"><i>l</i><sub class=\"lower-index\"><i>i</i></sub> + 2<i>k</i> - 1</span>, <span class=\"tex-span\"><i>l</i><sub class=\"lower-index\"><i>i</i></sub> + 3<i>k</i> - 1</span>, ..., <span class=\"tex-span\"><i>r</i><sub class=\"lower-index\"><i>i</i></sub></span>?\"</p><p>Dima hates to say \"no\" to Inna. That's why he wonders, what number of actions he will have to make for each question to make the answer to the question positive. In one action, Dima can either secretly take the candy from any box or put a candy to any box (Dima has infinitely many candies). Help Dima count the number of actions for each Inna's question.</p><p>Please note that Dima doesn't change the array during Inna's questions. That's why when you calculate the number of operations for the current question, please assume that the sequence of boxes didn't change.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line of the input contains three integers <span class=\"tex-span\"><i>n</i></span>, <span class=\"tex-span\"><i>k</i></span> and <span class=\"tex-span\"><i>w</i></span> <span class=\"tex-span\">(1 ≤ <i>k</i> ≤ <i>min</i>(<i>n</i>, 10), 1 ≤ <i>n</i>, <i>w</i> ≤ 10<sup class=\"upper-index\">5</sup>)</span>. The second line contains <span class=\"tex-span\"><i>n</i></span> characters. If the <span class=\"tex-span\"><i>i</i></span>-th box contains a candy, the <span class=\"tex-span\"><i>i</i></span>-th character of the line equals 1, otherwise it equals 0.</p><p>Each of the following <span class=\"tex-span\"><i>w</i></span> lines contains two integers <span class=\"tex-span\"><i>l</i><sub class=\"lower-index\"><i>i</i></sub></span> and <span class=\"tex-span\"><i>r</i><sub class=\"lower-index\"><i>i</i></sub></span> <span class=\"tex-span\">(1 ≤ <i>l</i><sub class=\"lower-index\"><i>i</i></sub> ≤ <i>r</i><sub class=\"lower-index\"><i>i</i></sub> ≤ <i>n</i>)</span> — the description of the <span class=\"tex-span\"><i>i</i></span>-th question. It is guaranteed that <span class=\"tex-span\"><i>r</i><sub class=\"lower-index\"><i>i</i></sub> - <i>l</i><sub class=\"lower-index\"><i>i</i></sub> + 1</span> is divisible by <span class=\"tex-span\"><i>k</i></span>.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>For each question, print a single number on a single line — the minimum number of operations Dima needs to make the answer to the question positive.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>10 3 3<br/>1010100011<br/>1 3<br/>1 6<br/>4 9<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1<br/>3<br/>2<br/></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>For the first question, you need to take a candy from the first box to make the answer positive. So the answer is 1.</p><p>For the second question, you need to take a candy from the first box, take a candy from the fifth box and put a candy to the sixth box. The answer is 3.</p><p>For the third question, you need to take a candy from the fifth box and put it to the sixth box. The answer is 2.</p></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"a0e38c761382c731f218c71f596606dd\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - C - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"d468883313d2f01f0365840b13075e5c5bb1675c\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - C - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/73366/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/73366/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/73366/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/73366/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/73366/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/73366/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/73366/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/73366/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/73366/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/73366/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/73366/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/73366/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/73366/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/73366/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/css/sidebar-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/a037fe51637846d9c7c725713cd840ea/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/73366/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='a0e38c761382c731f218c71f596606dd'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/73366/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/73366/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fcontest%2F390%2Fproblem%2FC%3Flocale%3Den\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"current\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='a0e38c761382c731f218c71f596606dd'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:100%;\"><a style=\"color: black\" href=\"/contest/390\">Codeforces Round 229 (Div. 2)</a></th>\n </tr>\n <tr>\n <td class=\"left bottom\" colspan=\"1\"><span class=\"contest-state-phase\">Finished</span></td>\n </tr>\n </tbody>\n </table>\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Practice?\n <div class=\"top-links\">\n </div>\n </div>\n<div>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Want to solve the contest problems after the official contest ends? Just register for practice and you will be able to submit solutions.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"\" method=\"post\"><input type='hidden' name='csrf_token' value='a0e38c761382c731f218c71f596606dd'/>\r\n <input type=\"hidden\" name=\"action\" value=\"registerForPractice\"/>\r\n <input type=\"submit\" name=\"submit\" value=\"Register for practice\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div> \r\n</div>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox ContestVirtualFrame borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Virtual participation <i class=\"sidebar-caption-icon las la-angle-down\"></i>\r\n\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\" \"\r\n\r\n data-page-url=\"/data/sidebarFrames\"\r\n\r\n>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests.\n\nIf you've seen these problems, a virtual contest is not for you - solve these problems in the archive.\n\nIf you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.\n\nNever use someone else's code, read the tutorials or communicate with other person during a virtual contest.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"/contest/390/virtual\" method=\"get\">\r\n <input type=\"submit\" name=\"submit\" value=\"Start virtual contest\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div>\r\n</div>\r\n <script>\r\n $(function () {\r\n $(\".ContestVirtualFrame .sidebar-caption-icon\").click(function() {\r\n $(this).toggleClass(\"la-angle-down la-angle-right\");\r\n const $target = $(this).parent().next();\r\n $target.toggle();\r\n const dataPageUrl = $target.attr(\"data-page-url\");\r\n const collapsed = $(this).hasClass(\"la-angle-right\");\r\n const params = {\r\n action: \"setCollapsed\",\r\n sidebarFrameSimpleClassName: \"ContestVirtualFrame\",\r\n collapsed\r\n };\r\n $.each($target[0].attributes, function(i, a) {\r\n const name = a.name;\r\n if (name.startsWith(\"data-extra-key-\")) {\r\n const key = a.value;\r\n const keyIndex = parseInt(name.substring(\"data-extra-key-\".length));\r\n const value = $target.attr(\"data-extra-value-\" + keyIndex);\r\n params[key] = value;\r\n }\r\n });\r\n $.post(dataPageUrl, params, function (result) {\r\n if (result[\"success\"] !== \"true\") {\r\n Codeforces.showMessage(\"Failed to save collapsed state.\");\r\n }\r\n }, \"json\");\r\n return false;\r\n });\r\n })\r\n </script>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Problem tags\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Heaps, binary search trees, segment trees, hash tables, etc\">\r\n data structures\r\n</span>\r\n </div>\n <div style=\"clear:both;text-align:right;font-size:1.1rem;\">\r\n <span title=\"Please login into the Codeforces\" class=\"notice\">No tag edit access</span>\r\n </div>\r\n</div>\r\n </div>\n\r\n<form id=\"addTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='a0e38c761382c731f218c71f596606dd'/>\r\n <input name=\"action\" type=\"hidden\" value=\"addTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"6704\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<form id=\"removeTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='a0e38c761382c731f218c71f596606dd'/>\r\n <input name=\"action\" type=\"hidden\" value=\"removeTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"6704\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<script type=\"text/javascript\">\r\n $(\".tag-box img\").click(function () {\r\n var tagName = $(this).attr(\"value\");\r\n Codeforces.confirm(\"Are you sure you want to remove this tag?\", function () {\r\n $(\"#removeTagForm input[name=tagName]\").val(tagName);\r\n $(\"#removeTagForm\").submit();\r\n }, function () {\r\n }, \"Yes\", \"No\");\r\n });\r\n\r\n $(\"#addTagLink\").click(function () {\r\n $(this).hide();\r\n $(\"#addTagLabel\").show();\r\n return false;\r\n });\r\n\r\n $(\"#addTagSelect\").change(function () {\r\n var tagName = $(this).val();\r\n if (tagName === \"\") {\r\n $(\"#addTagLabel\").hide();\r\n $(\"#addTagLink\").show();\r\n } else {\r\n $(\"#addTagForm input[name=tagName]\").val(tagName);\r\n $(\"#addTagForm\").submit();\r\n }\r\n });\r\n</script>\r\n\r\n<style type=\"text/css\">\r\n#new-resource-form tr td {\r\npadding-top: 0.5em;\r\n}\r\n#new-resource-form input:not([type=\"submit\"]) {\r\nfont-size: 0.8em;\r\n}\r\n#new-resource-form select {\r\nfont-size: 0.8em;\r\n}\r\n.new-resource-error {\r\nfont-size: 0.8em;\r\n}\r\n.resource-locale {\r\ncolor: #666;\r\nfont-family: Consolas, \"Andale Mono WT\", \"Andale Mono\", \"Lucida Console\", \"Lucida Sans Typewriter\", \"DejaVu Sans Mono\", \"Bitstream Vera Sans Mono\", \"Liberation Mono\", \"Nimbus Mono L\", Monaco, \"Courier New\", Courier, monospace;\r\n}\r\n</style>\r\n<div class=\"roundbox sidebox sidebar-menu borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Contest materials\n<div class=\"top-links\">\n</div>\n</div>\n<ul>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/64453\" title=\"Editorial (Unofficial)\" target=\"_blank\">Editorial (Unofficial) <span class=\"resource-locale\">(en)</span></a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"17239\" resourceName=\"Editorial (Unofficial)\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n</ul>\r\n</div></div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li class=\"current selectedLava\"><a\r\n href=\"/contest/390\">Problems</a></li>\r\n <li><a\r\n href=\"/contest/390/submit\">Submit Code</a></li>\r\n <li><a\r\n href=\"/contest/390/my\">My Submissions</a></li>\r\n <li><a\r\n href=\"/contest/390/status\">Status</a></li>\r\n <li><a\r\n href=\"/contest/390/hacks\">Hacks</a></li>\r\n <li><a\r\n href=\"/contest/390/room/1\">Room</a></li>\r\n <li><a\r\n href=\"/contest/390/standings\">Standings</a></li>\r\n <li><a\r\n href=\"/contest/390/customtest\">Custom Invocation</a></li>\r\n</ul>\r\n</div>\n\r\n <style>\r\n #facebox .content:has(.diff-popup) {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n }\r\n\r\n .testCaseMarker {\r\n position: absolute;\r\n font-weight: bold;\r\n font-size: 1rem;\r\n }\r\n\r\n .diff-popup {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n display: none;\r\n overflow: auto;\r\n }\r\n\r\n .input-output-copier {\r\n font-size: 1.2rem;\r\n float: right;\r\n color: #888 !important;\r\n cursor: pointer;\r\n border: 1px solid rgb(185, 185, 185);\r\n padding: 3px;\r\n margin: 1px;\r\n line-height: 1.1rem;\r\n text-transform: none;\r\n }\r\n\r\n .input-output-copier:hover {\r\n background-color: #def;\r\n }\r\n\r\n .test-explanation textarea {\r\n width: 100%;\r\n height: 1.5em;\r\n }\r\n\r\n .pending-submission-message {\r\n color: darkorange !important;\r\n }\r\n </style>\r\n <script>\r\n const OPENING_SPACE = String.fromCharCode(1001);\r\n const CLOSING_SPACE = String.fromCharCode(1002);\r\n\r\n const nodeToText = function (node, pre) {\r\n let result = [];\r\n\r\n if (node.tagName === \"SCRIPT\" || node.tagName === \"math\"\r\n || (node.classList && node.classList.contains(\"input-output-copier\")))\r\n return [];\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(OPENING_SPACE);\r\n }\r\n\r\n if (node.nodeType === Node.TEXT_NODE) {\r\n let s = node.textContent;\r\n if (!pre) {\r\n s = s.replace(/\\s+/g, \" \");\r\n }\r\n if (s.length > 0) {\r\n result.push(s);\r\n }\r\n }\r\n\r\n if (pre && node.tagName === \"BR\") {\r\n result.push(\"\\n\");\r\n }\r\n\r\n node.childNodes.forEach(function (child) {\r\n result.push(nodeToText(child, node.tagName === \"PRE\").join(\"\"));\r\n });\r\n\r\n if (node.tagName === \"DIV\"\r\n || node.tagName === \"P\"\r\n || node.tagName === \"PRE\"\r\n || node.tagName === \"UL\"\r\n || node.tagName === \"LI\"\r\n ) {\r\n result.push(\"\\n\");\r\n }\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(CLOSING_SPACE);\r\n }\r\n\r\n return result;\r\n }\r\n\r\n const isSpecial = function (c) {\r\n return c === ',' || c === '.' || c === ';' || c === ')' || c === ' ';\r\n }\r\n\r\n const convertStatementToText = function(statmentNode) {\r\n const text = nodeToText(statmentNode, false).join(\"\").replace(/ +/g, \" \").replace(/\\n\\n+/g, \"\\n\\n\");\r\n let result = [];\r\n for (let i = 0; i < text.length; i++) {\r\n const c = text.charAt(i);\r\n if (c === OPENING_SPACE) {\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"C\" data-uuid=\"ps_fbbfa5d37e6062735d5247030f5c17429fcde668\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">C. Inna and Candy Boxes</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Inna loves sweets very much. She has <span class=\"tex-span\"><i>n</i></span> closed present boxes lines up in a row in front of her. Each of these boxes contains either a candy (Dima's work) or nothing (Sereja's work). Let's assume that the boxes are numbered from 1 to <span class=\"tex-span\"><i>n</i></span>, from left to right.</p><p>As the boxes are closed, Inna doesn't know which boxes contain candies and which boxes contain nothing. Inna chose number <span class=\"tex-span\"><i>k</i></span> and asked <span class=\"tex-span\"><i>w</i></span> questions to Dima to find that out. Each question is characterised by two integers <span class=\"tex-span\"><i>l</i><sub class=\"lower-index\"><i>i</i></sub>, <i>r</i><sub class=\"lower-index\"><i>i</i></sub></span> (<span class=\"tex-span\">1 ≤ <i>l</i><sub class=\"lower-index\"><i>i</i></sub> ≤ <i>r</i><sub class=\"lower-index\"><i>i</i></sub> ≤ <i>n</i></span>; <span class=\"tex-span\"><i>r</i> - <i>l</i> + 1</span> is divisible by <span class=\"tex-span\"><i>k</i></span>), the <span class=\"tex-span\"><i>i</i></span>-th question is: "Dima, is that true that among the boxes with numbers from <span class=\"tex-span\"><i>l</i><sub class=\"lower-index\"><i>i</i></sub></span> to <span class=\"tex-span\"><i>r</i><sub class=\"lower-index\"><i>i</i></sub></span>, inclusive, the candies lie <span class=\"tex-font-style-bf\">only</span> in boxes with numbers <span class=\"tex-span\"><i>l</i><sub class=\"lower-index\"><i>i</i></sub> + <i>k</i> - 1</span>, <span class=\"tex-span\"><i>l</i><sub class=\"lower-index\"><i>i</i></sub> + 2<i>k</i> - 1</span>, <span class=\"tex-span\"><i>l</i><sub class=\"lower-index\"><i>i</i></sub> + 3<i>k</i> - 1</span>, ..., <span class=\"tex-span\"><i>r</i><sub class=\"lower-index\"><i>i</i></sub></span>?"</p><p>Dima hates to say "no" to Inna. That's why he wonders, what number of actions he will have to make for each question to make the answer to the question positive. In one action, Dima can either secretly take the candy from any box or put a candy to any box (Dima has infinitely many candies). Help Dima count the number of actions for each Inna's question.</p><p>Please note that Dima doesn't change the array during Inna's questions. That's why when you calculate the number of operations for the current question, please assume that the sequence of boxes didn't change.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line of the input contains three integers <span class=\"tex-span\"><i>n</i></span>, <span class=\"tex-span\"><i>k</i></span> and <span class=\"tex-span\"><i>w</i></span> <span class=\"tex-span\">(1 ≤ <i>k</i> ≤ <i>min</i>(<i>n</i>, 10), 1 ≤ <i>n</i>, <i>w</i> ≤ 10<sup class=\"upper-index\">5</sup>)</span>. The second line contains <span class=\"tex-span\"><i>n</i></span> characters. If the <span class=\"tex-span\"><i>i</i></span>-th box contains a candy, the <span class=\"tex-span\"><i>i</i></span>-th character of the line equals 1, otherwise it equals 0.</p><p>Each of the following <span class=\"tex-span\"><i>w</i></span> lines contains two integers <span class=\"tex-span\"><i>l</i><sub class=\"lower-index\"><i>i</i></sub></span> and <span class=\"tex-span\"><i>r</i><sub class=\"lower-index\"><i>i</i></sub></span> <span class=\"tex-span\">(1 ≤ <i>l</i><sub class=\"lower-index\"><i>i</i></sub> ≤ <i>r</i><sub class=\"lower-index\"><i>i</i></sub> ≤ <i>n</i>)</span> — the description of the <span class=\"tex-span\"><i>i</i></span>-th question. It is guaranteed that <span class=\"tex-span\"><i>r</i><sub class=\"lower-index\"><i>i</i></sub> - <i>l</i><sub class=\"lower-index\"><i>i</i></sub> + 1</span> is divisible by <span class=\"tex-span\"><i>k</i></span>.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>For each question, print a single number on a single line — the minimum number of operations Dima needs to make the answer to the question positive.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>10 3 3<br />1010100011<br />1 3<br />1 6<br />4 9<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1<br />3<br />2<br /></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>For the first question, you need to take a candy from the first box to make the answer positive. So the answer is 1.</p><p>For the second question, you need to take a candy from the first box, take a candy from the fifth box and put a candy to the sixth box. The answer is 3.</p><p>For the third question, you need to take a candy from the fifth box and put it to the sixth box. The answer is 2.</p></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=C]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== statementText) {\r\n $problem.find(\".diff-notifier\").show();\r\n\r\n $problem.find(\".diff-notifier-close\").click(function() {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n $problem.find(\".diff-notifier\").hide();\r\n });\r\n\r\n $problem.find(\"a.view-changes\").click(function() {\r\n $.post(\"/data/diff\", {action: \"getDiff\", a: previousStatementText, b: statementText}, function (result) {\r\n if (result[\"success\"] === \"true\") {\r\n Codeforces.facebox(\".diff-popup\", \"//codeforces.org/s/73366\");\r\n $(\"#facebox .diff-popup\").html(result[\"diff\"]);\r\n }\r\n }, \"json\");\r\n });\r\n }\r\n } else {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n }\r\n });\r\n });\r\n </script>\r\n\r\n\r\n<script type=\"text/javascript\">\r\n $(document).ready(function () {\r\n window.changedTests = new Set();\r\n\r\n function endsWith(string, suffix) {\r\n return string.indexOf(suffix, string.length - suffix.length) !== -1;\r\n }\r\n\r\n const inputFileDiv = $(\"div.input-file\");\r\n const inputFile = inputFileDiv.text();\r\n const outputFileDiv = $(\"div.output-file\");\r\n const outputFile = outputFileDiv.text();\r\n\r\n\r\n if (!endsWith(inputFile, \"standard input\")\r\n && !endsWith(inputFile, \"standard input\")) {\r\n inputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n if (!endsWith(outputFile, \"standard output\")\r\n && !endsWith(outputFile, \"standard output\")) {\r\n outputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n const titleDiv = $(\"div.header div.title\");\r\n\r\n\r\n\r\n String.prototype.replaceAll = function (search, replace) {\r\n return this.split(search).join(replace);\r\n };\r\n\r\n $(\".sample-test .title\").each(function () {\r\n const preId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n const cpyId = (\"id\" + Math.random()).replaceAll(\".\", \"0\");\r\n\r\n $(this).parent().find(\"pre\").attr(\"id\", preId);\r\n const $copy = $(\"<div title='Copy' data-clipboard-target='#\" + preId + \"' id='\" + cpyId + \"' class='input-output-copier'>Copy</div>\");\r\n $(this).append($copy);\r\n\r\n const clipboard = new Clipboard('#' + cpyId, {\r\n text: function (trigger) {\r\n const pre = document.querySelector('#' + preId);\r\n const lines = pre.querySelectorAll(\".test-example-line\");\r\n return Codeforces.filterClipboardText(pre.innerText, lines.length);\r\n }\r\n });\r\n\r\n const isInput = $(this).parent().hasClass(\"input\");\r\n\r\n clipboard.on('success', function (e) {\r\n if (isInput) {\r\n Codeforces.showMessage(\"The example input has been copied into the clipboard\");\r\n } else {\r\n Codeforces.showMessage(\"The example output has been copied into the clipboard\");\r\n }\r\n e.clearSelection();\r\n });\r\n });\r\n\r\n $(\".test-form-item input\").change(function () {\r\n addPendingSubmissionMessage($($(this).closest(\"form\")), \"You changed the answer, do not forget to submit it if you want to save the changes\");\r\n const index = $(this).closest(\".problemindexholder\").attr(\"problemindex\");\r\n let test = \"\";\r\n $(this).closest(\"form input\").each(function () {\r\n const test_ = $(this).attr(\"name\");\r\n if (test_ && test_.substring(0, 4) === \"test\") {\r\n test = test_;\r\n }\r\n });\r\n if (index.length > 0 && test.length > 0) {\r\n const indexTest = index + \"::\" + test;\r\n window.changedTests.add(indexTest);\r\n }\r\n });\r\n\r\n $(window).on('beforeunload', function () {\r\n if (window.changedTests.size > 0) {\r\n return 'Dialog text here';\r\n }\r\n });\r\n\r\n autosize($('.test-explanation textarea'));\r\n\r\n $(\".test-example-line\").hover(function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n let top = 1E20;\r\n let left = 1E20;\r\n let problem = $(this).closest(\".problemindexholder\");\r\n $(this).closest(\".input\").find(\".\" + clazz).css(\"background-color\", \"#FFFDE7\").each(function() {\r\n top = Math.min(top, $(this).offset().top);\r\n left = Math.min(left, $(this).offset().left);\r\n });\r\n let testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n if (testCaseMarker.length === 0) {\r\n const html = \"<div class=\\\"testCaseMarker testCaseMarker_\" + end + \" notice\\\"></div>\";\r\n problem.append($(html));\r\n testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n }\r\n if (testCaseMarker) {\r\n testCaseMarker.show()\r\n .offset({top, left: left - 20})\r\n .text(end);\r\n }\r\n }\r\n }\r\n });\r\n }, function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === \"test-example-line-\") {\r\n let end = clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n $(\".\" + clazz).css(\"background-color\", \"\");\r\n $(this).closest(\".problemindexholder\").find(\".testCaseMarker_\" + end).hide();\r\n }\r\n }\r\n });\r\n });\r\n\r\n });\r\n</script>\r\n\r\n </div>\n </div>\n <br style=\"clear: both;\"/>\n <div id=\"footer\">\n <div><a href=\"https://codeforces.com/\">Codeforces</a> (c) Copyright 2010-2023 Mike Mirzayanov</div>\n <div>The only programming contests Web 2.0 platform</div>\n <div>Server time: <span class=\"format-timewithseconds\" data-locale=\"en\">Oct/07/2023 05:38:45</span> (j3).</div>\n <div>Desktop version, switch to <a rel=\"nofollow\" class=\"switchToMobile\" href=\"?mobile=true\">mobile version</a>.</div>\n <div class=\"smaller\"><a href=\"/privacy\">Privacy Policy</a></div>\n\n <div style=\"margin-top: 25px;\">\n Supported by\n </div>\n <div style=\"margin-top: 8px; padding-bottom: 20px; position: relative; left: 10px;\">\n <a href=\"https://ton.org/\"><img style=\"margin-right: 2em; width: 60px;\" src=\"//codeforces.org/s/73366/images/ton-100x100.png\" alt=\"TON\" title=\"TON\"/></a>\n <a href=\"http://ifmo.ru/en/\"><img style=\"width: 120px;\" src=\"//codeforces.org/s/73366/images/itmo_small_en-logo.png\" alt=\"ИТМО\" title=\"ИТМО\"/></a>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(function() {\n $(\".switchToMobile\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"true\"));\n return false;\n });\n $(\".switchToDesktop\").click(function() {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", \"false\"));\n return false;\n });\n });\n </script>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n if ($(window).width() < 1600) {\n $('.button-up').css('width', '30px').css('line-height', '30px').css('font-size', '20px');\n }\n\n if ($(window).width() >= 1200) {\n $ (window).scroll (function () {\n if ($ (this).scrollTop () > 100) {\n $ ('.button-up').fadeIn();\n } else {\n $ ('.button-up').fadeOut();\n }\n });\n\n $('.button-up').click(function () {\n $('body,html').animate({\n scrollTop: 0\n }, 500);\n return false;\n });\n\n $('.button-up').hover(function () {\n $(this).animate({\n 'opacity':'1'\n }).css({'background-color':'#e7ebf0','color':'#6a86a4'});\n }, function () {\n $(this).animate({\n 'opacity':'0.7'\n }).css({'background':'none','color':'#d3dbe4'});;\n });\n }\n Codeforces.focusOnError();\n });\n </script>\n <div class=\"userListsFacebox\" style=\"display:none;\">\n <div style=\"padding: 0.5em; width: 600px; max-height: 200px; overflow-y: auto\">\n<div class=\"datatable\"\n \n style=\"background-color: #E1E1E1; padding-bottom: 3px;\">\n <div class=\"lt\"> </div>\n <div class=\"rt\"> </div>\n <div class=\"lb\"> </div>\n <div class=\"rb\"> </div>\n\n <div style=\"padding: 4px 0 0 6px;font-size:1.4rem;position:relative;\">\n User lists\n\n <div style=\"position:absolute;right:0.25em;top:0.35em;\">\n <span style=\"padding:0;position:relative;bottom:2px;\" class=\"rowCount\"></span>\n\n <img class=\"closed\" src=\"//codeforces.org/s/73366/images/icons/control.png\"/>\n\n <span class=\"filter\" style=\"display:none;\">\n <img class=\"opened\" src=\"//codeforces.org/s/73366/images/icons/control-270.png\"/>\n <input style=\"padding:0 0 0 20px;position:relative;bottom:2px;border:1px solid #aaa;height:17px;font-size:1.3rem;\"/>\n </span>\n </div>\n </div>\n <div style=\"background-color: white;margin:0.3em 3px 0 3px;position:relative;\">\n <div class=\"ilt\"> </div>\n <div class=\"irt\"> </div>\n <table class=\"\">\n <thead>\n <tr>\n <th>Name</th>\n </tr>\n </thead>\n <tbody>\n </tbody>\n </table>\n </div>\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n // Create new ':containsIgnoreCase' selector for search\n jQuery.expr[':'].containsIgnoreCase = function(a, i, m) {\n return jQuery(a).text().toUpperCase()\n .indexOf(m[3].toUpperCase()) >= 0;\n };\n\n if (window.updateDatatableFilter == undefined) {\n window.updateDatatableFilter = function(i) {\n var parent = $(i).parent().parent().parent().parent();\n $(\"tr.no-items\", parent).remove();\n $(\"tr\", parent).hide().removeClass('visible');\n var text = $(i).val();\n if (text) {\n $(\"tr\" + \":containsIgnoreCase('\" + text + \"')\", parent).show().addClass('visible');\n } else {\n parent.find(\".rowCount\").text(\"\");\n $(\"tr\", parent).show().addClass('visible');\n }\n\n var found = false;\n var visibleRowCount = 0;\n $(\"tr\", parent).each(function () {\n if (!found) {\n if ($(this).find(\"th\").size() > 0) {\n $(this).show().addClass('visible');\n found = true;\n }\n }\n if ($(this).hasClass('visible')) {\n visibleRowCount++;\n }\n });\n if (text) {\n parent.find(\".rowCount\").text(\"Matches: \" + (visibleRowCount - (found ? 1 : 0)));\n }\n if (visibleRowCount == (found ? 1 : 0)) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo($(parent).find('table'));\n }\n $(parent).find(\"tr td\").removeClass(\"dark\");\n $(parent).find(\"tr.visible:odd td\").addClass(\"dark\");\n }\n\n $(\".datatable .closed\").click(function () {\n var parent = $(this).parent();\n $(this).hide();\n $(\".filter\", parent).fadeIn(function () {\n $(\"input\", parent).val(\"\").focus().css(\"border\", \"1px solid #aaa\");\n });\n });\n\n $(\".datatable .opened\").click(function () {\n var parent = $(this).parent().parent();\n $(\".filter\", parent).fadeOut(function () {\n $(\".closed\", parent).show();\n $(\"input\", parent).val(\"\").each(function () {\n window.updateDatatableFilter(this);\n });\n });\n });\n\n $(\".datatable .filter input\").keyup(function(e) {\n window.updateDatatableFilter(this);\n e.preventDefault();\n e.stopPropagation();\n });\n\n $(\".datatable table\").each(function () {\n var found = false;\n $(\"tr\", this).each(function () {\n if (!found && $(this).find(\"th\").size() == 0) {\n found = true;\n }\n });\n if (!found) {\n $(\"<tr class='no-items visible'><td style=\\\"text-align:left;\\\"colspan=\\\"32\\\">No items<\\/td><\\/tr>\").appendTo(this);\n }\n });\n\n // Applies styles to datatables.\n $(\".datatable\").each(function () {\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n\n $(\".datatable table.tablesorter\").each(function () {\n $(this).bind(\"sortEnd\", function () {\n $(\".datatable\").each(function () {\n $(this).find(\"th, td\")\n .removeClass(\"top\").removeClass(\"bottom\")\n .removeClass(\"left\").removeClass(\"right\")\n .removeClass(\"dark\");\n $(this).find(\"tr:first th\").addClass(\"top\");\n $(this).find(\"tr:last td\").addClass(\"bottom\");\n $(this).find(\"tr:odd td\").addClass(\"dark\");\n $(this).find(\"tr td:first-child, tr th:first-child\").addClass(\"left\");\n $(this).find(\"tr td:last-child, tr th:last-child\").addClass(\"right\");\n });\n });\n });\n }\n });\n </script>\n </div>\n </div>\n <script type=\"application/javascript\">\n $(function() {\n $(\".userListMarker\").click(function() {\n $.post(\"/data/lists\", {action: \"findTouched\"}, function(json) {\n Codeforces.facebox(\".userListsFacebox\");\n var tbody = $(\"#facebox tbody\");\n tbody.empty();\n for (var i in json) {\n tbody.append(\n $(\"<tr></tr>\").append(\n $(\"<td></td>\").attr(\"data-readKey\", json[i].readKey).text(json[i].name)\n )\n );\n }\n Codeforces.updateDatatables();\n tbody.find(\"td\").css(\"cursor\", \"pointer\").click(function() {\n document.location = Codeforces.updateUrlParameter(document.location.href, \"list\", $(this).attr(\"data-readKey\"));\n });\n }, \"json\");\n });\n });\n </script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-73366.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'8122c50e3cfd75a7',t:'MTY5NjY0NjMyNS41MzkwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"},"long_tags":{"kind":"string","value":"[\"Heaps, binary search trees, segment trees, hash tables, etc\"]"},"short_tags":{"kind":"string","value":"[\"data structures\"]"},"tutorial_link":{"kind":"string","value":"https://codeforces.com/blog/entry/64453"},"tutorial_page":{"kind":"string","value":"\r\n\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"642864061f7f8f253cd15a412d138165\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"h1\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Codeforces Round #229 (Div. 2) Editorial [Unofficial] - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n \n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Codeforces Round #229 (Div. 2) Editorial [Unofficial] - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. Programming competitions and contests, programming community\" />\n <meta name=\"keywords\" content=\"programming algorithm contest competition informatics olympiads c++ java graphs vkcup\" />\n <meta name=\"robots\" content=\"index, follow\" />\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/font-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/line-awesome.min.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <link href='//fonts.googleapis.com/css?family=PT+Sans+Narrow:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n <link href='//fonts.googleapis.com/css?family=Cuprum&subset=latin,cyrillic' rel='stylesheet' type='text/css'>\n\n\n <link rel=\"apple-touch-icon\" sizes=\"57x57\" href=\"//codeforces.org/s/81027/apple-icon-57x57.png\">\n <link rel=\"apple-touch-icon\" sizes=\"60x60\" href=\"//codeforces.org/s/81027/apple-icon-60x60.png\">\n <link rel=\"apple-touch-icon\" sizes=\"72x72\" href=\"//codeforces.org/s/81027/apple-icon-72x72.png\">\n <link rel=\"apple-touch-icon\" sizes=\"76x76\" href=\"//codeforces.org/s/81027/apple-icon-76x76.png\">\n <link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"//codeforces.org/s/81027/apple-icon-114x114.png\">\n <link rel=\"apple-touch-icon\" sizes=\"120x120\" href=\"//codeforces.org/s/81027/apple-icon-120x120.png\">\n <link rel=\"apple-touch-icon\" sizes=\"144x144\" href=\"//codeforces.org/s/81027/apple-icon-144x144.png\">\n <link rel=\"apple-touch-icon\" sizes=\"152x152\" href=\"//codeforces.org/s/81027/apple-icon-152x152.png\">\n <link rel=\"apple-touch-icon\" sizes=\"180x180\" href=\"//codeforces.org/s/81027/apple-icon-180x180.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"192x192\" href=\"//codeforces.org/s/81027/android-icon-192x192.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"32x32\" href=\"//codeforces.org/s/81027/favicon-32x32.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"96x96\" href=\"//codeforces.org/s/81027/favicon-96x96.png\">\n <link rel=\"icon\" type=\"image/png\" sizes=\"16x16\" href=\"//codeforces.org/s/81027/favicon-16x16.png\">\n <link rel=\"manifest\" href=\"/manifest.json\">\n <meta name=\"msapplication-TileColor\" content=\"#ffffff\">\n <meta name=\"msapplication-TileImage\" content=\"//codeforces.org/s/81027/ms-icon-144x144.png\">\n <meta name=\"theme-color\" content=\"#ffffff\">\n\n <!--CombineResourcesFilter-->\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/prettify.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/clear.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/ttypography.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/problem-statement.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/second-level-menu.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/roundbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/datatable.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/table-form.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/topic.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.jgrowl.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/facebox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.wysiwyg.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.autocomplete.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/codeforces.datepick.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/colorbox.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/jquery.drafts.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/css/community.css\" type=\"text/css\" charset=\"utf-8\" />\n\n <!-- MathJax -->\n <script type=\"text/x-mathjax-config\">\n MathJax.Hub.Config({\n tex2jax: {inlineMath: [['$$$','$$$']], displayMath: [['$$$$$$','$$$$$$']]}\n });\n MathJax.Hub.Register.StartupHook(\"End\", function () {\n Codeforces.runMathJaxListeners();\n });\n </script>\n <script type=\"text/javascript\" async\n src=\"https://mathjax.codeforces.org/MathJax.js?config=TeX-AMS_HTML-full\"\n >\n </script>\n <!-- /MathJax -->\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/prettify/prettify.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/moment-with-locales.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/pushstream.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.easing.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.lavalamp.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.jgrowl.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.swipe.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.hotkeys.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/facebox.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.wysiwyg.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.colorpicker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.table.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.image.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/controls/wysiwyg.link.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.autocomplete.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.datepick.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ie6blocker.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.colorbox-min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.ba-bbq.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/jquery.drafts.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/clipboard.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/autosize.min.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/sjcl.js\"></script>\n <script type=\"text/javascript\" src=\"/scripts/573cedc6b04c15481941f418269f4057/en/codeforces-options.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/codeforces.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/EventCatcher.js?v=20160131\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/preparedVerdictFormats-en.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/js/confetti.min.js\"></script>\n <!--/CombineResourcesFilter-->\n\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/skins/markitup/style.css\" type=\"text/css\" charset=\"utf-8\" />\n <link rel=\"stylesheet\" href=\"//codeforces.org/s/81027/markitup/sets/markdown/style.css\" type=\"text/css\" charset=\"utf-8\" />\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/jquery.markitup.js\"></script>\n <script type=\"text/javascript\" src=\"//codeforces.org/s/81027/markitup/sets/markdown/set.js\"></script>\n\n <!--[if IE]>\n <style>\n #sidebar {\n padding-left: 1em;\n margin: 1em 1em 1em 0;\n }\n </style>\n <![endif]-->\n\n\n\n\n</head>\n<body class=\" \"><span style='display:none;' class='csrf-token' data-csrf='642864061f7f8f253cd15a412d138165'> </span>\n\n<!-- .notificationTextCleaner used in Codeforces.showAnnouncements() -->\n<div class=\"notificationTextCleaner\" style=\"font-size: 0\"></div>\n<div class=\"button-up\" style=\"display: none; opacity: 0.7; width: 50px; height:100%; position: fixed; left: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 3.0rem;\"><i class=\"icon-circle-arrow-up\"></i></div>\n<div class=\"verdictPrototypeDiv\" style=\"display: none;\"></div>\n\n<!-- Codeforces JavaScripts. -->\n<script type=\"text/javascript\">\n String.prototype.hashCode = function() {\n var hash = 0, i, chr;\n if (this.length === 0) return hash;\n for (i = 0; i < this.length; i++) {\n chr = this.charCodeAt(i);\n hash = ((hash << 5) - hash) + chr;\n hash |= 0; // Convert to 32bit integer\n }\n return hash;\n };\n\n var queryMobile = Codeforces.queryString.mobile;\n if (queryMobile === \"true\" || queryMobile === \"false\") {\n Codeforces.putToStorage(\"useMobile\", queryMobile === \"true\");\n } else {\n var useMobile = Codeforces.getFromStorage(\"useMobile\");\n if (useMobile === true || useMobile === false) {\n if (useMobile != false) {\n Codeforces.redirect(Codeforces.updateUrlParameter(document.location.href, \"mobile\", useMobile));\n }\n }\n }\n</script>\n\n<script type=\"text/javascript\">\n if (window.parent.frames.length > 0) {\n window.stop();\n }\n</script>\n\n\n\n\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n (function () {\n jQuery.expr[':'].containsCI = function(elem, index, match) {\n return !match || !match.length || match.length < 4 || !match[3] || (\n elem.textContent || elem.innerText || jQuery(elem).text() || ''\n ).toLowerCase().indexOf(match[3].toLowerCase()) >= 0;\n }\n }(jQuery));\n\n $.ajaxPrefilter(function(options, originalOptions, xhr) {\n var csrf = Codeforces.getCsrfToken();\n\n if (csrf) {\n var data = originalOptions.data;\n if (originalOptions.data !== undefined) {\n if (Object.prototype.toString.call(originalOptions.data) === '[object String]') {\n data = $.deparam(originalOptions.data);\n }\n } else {\n data = {};\n }\n options.data = $.param($.extend(data, { csrf_token: csrf }));\n }\n });\n\n window.getCodeforcesServerTime = function(callback) {\n $.post(\"/data/time\", {}, callback, \"json\");\n }\n\n window.updateTypography = function () {\n $(\"div.ttypography code\").addClass(\"tt\");\n $(\"div.ttypography pre>code\").addClass(\"prettyprint\").removeClass(\"tt\");\n $(\"div.ttypography table\").addClass(\"bordertable\");\n prettyPrint();\n }\n\n $.ajaxSetup({ scriptCharset: \"utf-8\" ,contentType: \"application/x-www-form-urlencoded; charset=UTF-8\", headers: {\n 'X-Csrf-Token': Codeforces.getCsrfToken()\n }});\n\n window.updateTypography();\n\n Codeforces.signForms();\n\n setTimeout(function() {\n $(\".second-level-menu-list\").lavaLamp({\n fx: \"backout\",\n speed: 700\n });\n }, 100);\n\n\n Codeforces.countdown();\n $(\"a[rel='photobox']\").colorbox();\n\n\n function showAnnouncements(json) {\n //info(\"j=\" + JSON.stringify(json));\n\n if (json.t != \"a\") {\n return;\n }\n\n setTimeout(function() {\n Codeforces.showAnnouncements(json.d, \"en\");\n }, Math.random() * 500);\n }\n\n function showEventCatcherUserMessage(json) {\n if (json.t == \"s\") {\n var points = json.d[5];\n var passedTestCount = json.d[7];\n var judgedTestCount = json.d[8];\n var verdict = preparedVerdictFormats[json.d[12]];\n var verdictPrototypeDiv = $(\".verdictPrototypeDiv\");\n verdictPrototypeDiv.html(verdict);\n if (judgedTestCount != null && judgedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-judged\").text(judgedTestCount);\n }\n if (passedTestCount != null && passedTestCount != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-passed\").text(passedTestCount);\n }\n if (points != null && points != undefined) {\n verdictPrototypeDiv.find(\".verdict-format-points\").text(points);\n }\n Codeforces.showMessage(verdictPrototypeDiv.text());\n }\n }\n\n $(\".clickable-title\").each(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n var tmp = document.createElement(\"DIV\");\n tmp.innerHTML = title;\n $(this).attr(\"title\", tmp.textContent || tmp.innerText || \"\");\n }\n });\n\n $(\".clickable-title\").click(function() {\n var title = $(this).attr(\"data-title\");\n if (title) {\n Codeforces.alert(title);\n } else {\n Codeforces.alert($(this).attr(\"title\"));\n }\n }).css(\"position\", \"relative\").css(\"bottom\", \"3px\");\n\n Codeforces.showDelayedMessage();\n\n Codeforces.reformatTimes();\n\n //Codeforces.initializePubSub();\n if (window.codeforcesOptions.subscribeServerUrl) {\n window.eventCatcher = new EventCatcher(\n window.codeforcesOptions.subscribeServerUrl,\n [\n Codeforces.getGlobalChannel(),\n Codeforces.getUserChannel(),\n Codeforces.getUserShowMessageChannel(),\n Codeforces.getContestChannel(),\n Codeforces.getParticipantChannel(),\n Codeforces.getTalkChannel()\n ]\n );\n\n if (Codeforces.getParticipantChannel()) {\n window.eventCatcher.subscribe(Codeforces.getParticipantChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getContestChannel()) {\n window.eventCatcher.subscribe(Codeforces.getContestChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getGlobalChannel()) {\n window.eventCatcher.subscribe(Codeforces.getGlobalChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserChannel(), function(json) {\n showAnnouncements(json);\n });\n }\n\n if (Codeforces.getUserShowMessageChannel()) {\n window.eventCatcher.subscribe(Codeforces.getUserShowMessageChannel(), function(json) {\n showEventCatcherUserMessage(json);\n });\n }\n }\n\n Codeforces.setupContestTimes(\"/data/contests\");\n Codeforces.setupSpoilers();\n Codeforces.setupTutorials(\"/data/problemTutorial\");\n });\n </script>\n\n<script type=\"text/javascript\">\n var _gaq = _gaq || [];\n _gaq.push(['_setAccount', 'UA-743380-5']);\n _gaq.push(['_trackPageview']);\n\n (function () {\n var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;\n ga.src = (document.location.protocol == 'https:' ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);\n })();\n</script>\n\n\n<div id=\"body\">\n \r\n\r\n<div class=\"side-bell\" style=\"visibility: hidden; display: none; opacity: 0.7; width: 40px; position: fixed; right: 0; top: 0; cursor: pointer; text-align: center; line-height: 35px; color: #d3dbe4; font-weight: bold; font-size: 1.5rem;\">\r\n <span class=\"icon-stack\" style=\"width: 100%;\">\r\n <i class=\"icon-circle icon-stack-base\"></i>\r\n <i class=\"icon-bell-alt icon-light\"></i>\r\n </span>\r\n <br/>\r\n <span class=\"side-bell__count\" style=\"position: relative; top: -10px;\"></span>\r\n</div>\r\n\r\n\r\n<div id=\"header\" style=\"position: relative;\">\r\n <div style=\"float:left; max-height: 60px;\">\r\n <a href=\"/\"><img height=\"65\" style=\"height: 65px;\" alt=\"Codeforces\" title=\"Codeforces\" src=\"//codeforces.org/s/81027/images/codeforces-sponsored-by-ton.png\"/></a>\r\n </div>\r\n <div class=\"lang-chooser\">\r\n <div style=\"text-align: right;\">\r\n <a href=\"?locale=en\"><img src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" title=\"In English\" alt=\"In English\"/></a>\r\n <a href=\"?locale=ru\"><img src=\"//codeforces.org/s/81027/images/flags/24/ru.png\" title=\"По-русски\" alt=\"По-русски\"/></a>\r\n </div>\r\n\r\n <div >\r\n <a href=\"/enter?back=%2Fblog%2Fentry%2F64453\">Enter</a>\r\n | \r\n <a href=\"/register\">Register</a>\r\n \r\n </div>\r\n\r\n\r\n\r\n </div>\r\n <br style=\"clear: both;\"/>\r\n</div>\n \r\n\r\n\n <div class=\"roundbox menu-box borderTopRound borderBottomRound\" style=\"\">\n <div class=\"menu-list-container\">\r\n <ul class=\"menu-list main-menu-list\">\r\n <li class=\"\"><a href=\"/\">Home</a></li>\r\n <li class=\"\"><a href=\"/top\">Top</a></li>\r\n <li class=\"\"><a href=\"/catalog\">Catalog</a></li>\r\n <li class=\"\"><a href=\"/contests\">Contests</a></li>\r\n <li class=\"\"><a href=\"/gyms\">Gym</a></li>\r\n <li class=\"\"><a href=\"/problemset\">Problemset</a></li>\r\n <li class=\"\"><a href=\"/groups\">Groups</a></li>\r\n <li class=\"\"><a href=\"/ratings\">Rating</a></li>\r\n <li class=\"\"><a href=\"/edu/courses\"><span class=\"edu-menu-item\">Edu</span></a></li>\r\n <li class=\"\"><a href=\"/apiHelp\">API</a></li>\r\n <li class=\"\"><a href=\"/calendar\">Calendar</a></li>\r\n <li class=\"\"><a href=\"/help\">Help</a></li>\r\n </ul>\r\n <form method=\"post\" action=\"/search\"><input type='hidden' name='csrf_token' value='642864061f7f8f253cd15a412d138165'/>\r\n <input class=\"search\" name=\"query\" data-isPlaceholder=\"true\" value=\"\"/>\r\n </form>\r\n <br style=\"clear: both;\"/>\r\n</div>\r\n\r\n </div>\n\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\"input.search\").focus(function () {\n if ($(this).attr(\"data-isPlaceholder\") === \"true\") {\n $(this).val(\"\");\n $(this).removeAttr(\"data-isPlaceholder\");\n }\n });\n });\n </script>\n <br style=\"height: 3em; clear: both;\"/>\n\n <div style=\"position: relative;\">\n <div id=\"sidebar\">\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Pay attention\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n <div style=\"text-align:center;border-bottom: 1px solid rgb(185, 185, 185);margin:0 -0.5em 0.5em -0.5em;padding: 0 1em 0.5em 1em;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 1, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:51:52</span><br/><a href=\"/contestRegistration/1876\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n <div style=\"text-align:center;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 2, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:51:52</span><br/><a href=\"/contestRegistration/1877\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='642864061f7f8f253cd15a412d138165'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n </label>\r\n </div>\r\n <div style=\"padding: 0 1em 1em 1em;text-align:right;\">\r\n <input style=\"height:1.65em;padding:0 0.75em;\" type=\"submit\" value=\"Find\"/>\r\n </div>\r\n </form>\r\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".handleBox\").autocomplete(\"/data/handles\", {\r\n delay: 200,\r\n width: 200,\r\n selectFirst: false,\r\n matchContains: true,\r\n minChars: 3\r\n });\r\n $(\".handleForm\").attr(\"autocomplete\", \"off\").submit(function () {\r\n var link = \"/profile/userHandle\".replace(\r\n \"userHandle\", $(this).find(\".handleBox\").val()\r\n );\r\n window.location = link;\r\n return false;\r\n });\r\n });\n </script>\n\r\n\r\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Recent actions\n <div class=\"top-links\">\n </div>\n </div>\n <div class=\"recent-actions\">\r\n <ul>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/121073\">Meta Hacker Cup 2023 Round 1</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/.Danet\" title=\"Expert .Danet\" class=\"rated-user user-blue\">.Danet</a> →\r\n <a href=\"/blog/entry/121172\">[TLE on pretest1]</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\" class=\"rated-user user-red\">Pyqe</a> →\r\n <a href=\"/blog/entry/121025\">Codeforces Round #902 (Div. 1, Div. 2, based on COMPFEST 15 — Final Round)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pranshu_Pandya\" title=\"Specialist Pranshu_Pandya\" class=\"rated-user user-cyan\">Pranshu_Pandya</a> →\r\n <a href=\"/blog/entry/121171\">An Interesting Tree Problem</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/sszcdjr\" title=\"Master sszcdjr\" class=\"rated-user user-orange\">sszcdjr</a> →\r\n <a href=\"/blog/entry/119859\">Codeforces Round 896 (Div. 1, Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/119880\">It's Happening! Meta Hacker Cup 2023 Schedule</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/DaviddeGea1\" title=\"Expert DaviddeGea1\" class=\"rated-user user-blue\">DaviddeGea1</a> →\r\n <a href=\"/blog/entry/70917\">Number of ways of dividing an array into 2 parts such that sum of each part is > k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bekh\" title=\"Master Bekh\" class=\"rated-user user-orange\">Bekh</a> →\r\n <a href=\"/blog/entry/74245\">Questions and doubts regarding Aliens DP trick</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a> →\r\n <a href=\"/blog/entry/8192\">Codeforces Round #190 — Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/hocky\" title=\"Candidate Master hocky\" class=\"rated-user user-violet\">hocky</a> →\r\n <a href=\"/blog/entry/95323\">FBHC wuining uw Day? Incwease uw stacc size! (ㅅ´ ˘ `)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/liouzhou_101\" title=\"International Master liouzhou_101\" class=\"rated-user user-orange\">liouzhou_101</a> →\r\n <a href=\"/blog/entry/87598\">Editorial of Codeforces Round #700</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/yeon_gist\" title=\"Newbie yeon_gist\" class=\"rated-user user-gray\">yeon_gist</a> →\r\n <a href=\"/blog/entry/121170\">plusMinusPermutation computing error</a>\r\n <img alt=\"Text created or updated\" title=\"Text created or updated\" src=\"//codeforces.org/s/81027/images/icons/x-update-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/altforminuscontribution\" title=\"Newbie altforminuscontribution\" class=\"rated-user user-gray\">altforminuscontribution</a> →\r\n <a href=\"/blog/entry/121162\">My screen get unexpectedly big, what should I do</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/atcoder_official\" title=\"Unrated, atcoder_official\" class=\"rated-user user-black\">atcoder_official</a> →\r\n <a href=\"/blog/entry/121120\">We will hold UNIQUE VISION Programming Contest 2023 Autumn(AtCoder Beginner Contest 323)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/YouStill_DontKnowMeYet\" title=\"Candidate Master YouStill_DontKnowMeYet\" class=\"rated-user user-violet\">YouStill_DontKnowMeYet</a> →\r\n <a href=\"/blog/entry/117659\">[GYM] Al-Baath Collegiate Programming Contest 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/ankancool\" title=\"Expert ankancool\" class=\"rated-user user-blue\">ankancool</a> →\r\n <a href=\"/blog/entry/121136\">Invitation to AstroByte 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/GeZhiyuan\" title=\"Grandmaster GeZhiyuan\" class=\"rated-user user-red\">GeZhiyuan</a> →\r\n <a href=\"/blog/entry/120943\">Codeforces Round 901 (Div. 1, Div. 2) Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a> →\r\n <a href=\"/blog/entry/120772\">PSA: Increase your stack size before the Meta Hacker Cup, here's how</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/dino_merlin\" title=\"Expert dino_merlin\" class=\"rated-user user-blue\">dino_merlin</a> →\r\n <a href=\"/blog/entry/121145\">Intuitive approach for CEOI Kangaroo?</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/icecuber\" title=\"Grandmaster icecuber\" class=\"rated-user user-red\">icecuber</a> →\r\n <a href=\"/blog/entry/70018\">CSES DP section editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bn00b\" title=\"Newbie Bn00b\" class=\"rated-user user-gray\">Bn00b</a> →\r\n <a href=\"/blog/entry/98820\">[FEATURE REQUEST : ATCODER] TOPICS TAGS AND SORTING BY SOLVE COUNT</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a> →\r\n <a href=\"/blog/entry/121163\">AtCoder Regular Contest 166 Announcement</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/windva\" title=\"Grandmaster windva\" class=\"rated-user user-red\">windva</a> →\r\n <a href=\"/blog/entry/120644\">Codeforces Round 899 (Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Misa-Misa\" title=\"Expert Misa-Misa\" class=\"rated-user user-blue\">Misa-Misa</a> →\r\n <a href=\"/blog/entry/121157\">Someone please help me understand this.</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/shivam565\" title=\"Specialist shivam565\" class=\"rated-user user-cyan\">shivam565</a> →\r\n <a href=\"/blog/entry/108348\">Total number of subarrays with sum atmost k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n </ul>\r\n </div>\r\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/recent-actions\">Detailed →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n</div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li><a\r\n href=\"/profile/AkiLotus\">AkiLotus</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/AkiLotus\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/AkiLotus\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/AkiLotus\">Submissions</a></li>\r\n <li><a\r\n href=\"/groups/with/AkiLotus\">Groups</a></li>\r\n <li><a\r\n href=\"/contests/with/AkiLotus\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/AkiLotus\">Problemsetting</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/AkiLotus\" style=\"text-decoration:none;color:black !important;\">AkiLotus's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"64858\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/64453\"> <p>Codeforces Round #229 (Div. 2) Editorial [Unofficial]</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/AkiLotus\" title=\"Master AkiLotus\" class=\"rated-user user-orange\">AkiLotus</a>,\r\n <a href=\"/topic/64858/en4\">history</a>,\r\n <span class=\"format-humantime\" title=\"Jan/11/2019 15:40\">5 years ago</span>,\r\n \r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p><em>Since the original data has been lost during the dark days of Codeforces, no version of the editorial has been re-released, and I feel the round itself is quite educational, so I decided to give a try.</em></p><h2><a href=\"/contest/390/problem/A\" title=\"Codeforces Round 229 (Div. 2)\">390A - Инна и будильники</a></h2> <div class=\"spoiler\"><b class=\"spoiler-title\">Approach</b><div class=\"spoiler-content\" style=\"display: none;\"><p>The criterion shows that we can only use either vertical segments or horizontal segments.<br />Since there is no limit on the segments' length, we can see that it's always optimal to use a segment with infinite length (or may be known as a line).</p><p>We can see that the vertical line <span class=\"tex-span\"><i>x</i> = <i>a</i></span> will span through every alarm clocks standing at positions with x-coordinate being equal to <span class=\"tex-span\"><i>a</i></span>. In a similar manner, the horizontal line <span class=\"tex-span\"><i>y</i> = <i>b</i></span> will span through every alarm clocks standing at positions with y-coordinate being equal to <span class=\"tex-span\"><i>b</i></span>.</p><p>So, if we use vertical lines, the number of segments used will be the number of distinct values of x-coordinates found in the data. Similarly, the number of horizontal segments used will be the number of distinct values of y-coordinates found.</p><p>The process can be implemented by a counting array, or a map.</p><p>Time complexity: <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/e98e669660e295d23c96117b197140d3a3709707.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> for regular arrays, or <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/df2dace9ef526732e09735cc52a919faad47f167.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> for maps.</p></div></div> <div class=\"spoiler\"><b class=\"spoiler-title\">Solution 1 (Map)</b><div class=\"spoiler-content\" style=\"display: none;\"><p>Submission link: <a href=\"/contest/390/submission/48214007\" title=\"Посылка 48214007 от AkiLotus\">48214007</a></p> <div class=\"spoiler\"><b class=\"spoiler-title\">Source code in plain text</b><div class=\"spoiler-content\" style=\"display: none;\"><pre><code>#pragma GCC optimize("Ofast")\n\n#include <bits/stdc++.h>\nusing namespace std;\n\n#define endl '\\n'\nmt19937 rng32(chrono::steady_clock::now().time_since_epoch().count());\nmt19937_64 rng64(chrono::steady_clock::now().time_since_epoch().count());\n\nint main(int argc, char* argv[]) {\n\tios_base::sync_with_stdio(0); cin.tie(NULL);\n\t\n\tint n; cin >> n;\n\t\n\tmap<int, int> cntx, cnty;\n\t\n\twhile (n--) {\n\t\tint x, y;\n\t\tcin >> x >> y;\n\t\tcntx[x]++; cnty[y]++;\n\t}\n\t\n\tcout << min(cntx.size(), cnty.size()) << endl;\n\t\n\treturn 0;\n}\n</code></pre></div></div></div></div> <div class=\"spoiler\"><b class=\"spoiler-title\">Solution 2 (Array)</b><div class=\"spoiler-content\" style=\"display: none;\"><p>Submission link: <a href=\"/contest/390/submission/48213984\" title=\"Посылка 48213984 от AkiLotus\">48213984</a></p> <div class=\"spoiler\"><b class=\"spoiler-title\">Source code in plain text</b><div class=\"spoiler-content\" style=\"display: none;\"><pre><code>#pragma GCC optimize("Ofast")\n\n#include <bits/stdc++.h>\nusing namespace std;\n\n#define endl '\\n'\nmt19937 rng32(chrono::steady_clock::now().time_since_epoch().count());\nmt19937_64 rng64(chrono::steady_clock::now().time_since_epoch().count());\n\nint main(int argc, char* argv[]) {\n\tios_base::sync_with_stdio(0); cin.tie(NULL);\n\t\n\tint n; cin >> n;\n\t\n\tvector<int> cntx(101, 0);\n\tvector<int> cnty(101, 0);\n\t\n\twhile (n--) {\n\t\tint x, y;\n\t\tcin >> x >> y;\n\t\tcntx[x]++; cnty[y]++;\n\t}\n\t\n\tint distinctx = 0, distincty = 0;\n\tfor (int i=0; i<101; i++) {\n\t distinctx += (cntx[i] > 0);\n\t distincty += (cnty[i] > 0);\n\t}\n\t\n\tcout << min(distinctx, distincty) << endl;\n\t\n\treturn 0;\n}\n</code></pre></div></div></div></div><h2><a href=\"/contest/390/problem/B\" title=\"Codeforces Round 229 (Div. 2)\">390B - Инна, Дима и песня</a></h2> <div class=\"spoiler\"><b class=\"spoiler-title\">Approach</b><div class=\"spoiler-content\" style=\"display: none;\"><p>From the constraints given, for the <span class=\"tex-span\"><i>i</i></span>-th song, provided there exists corresponding <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span> and <span class=\"tex-span\"><i>y</i><sub class=\"lower-index\"><i>i</i></sub></span> values, then the following inequality must hold: <span class=\"tex-span\">2 ≤ <i>x</i><sub class=\"lower-index\"><i>i</i></sub> + <i>y</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 2·<i>a</i><sub class=\"lower-index\"><i>i</i></sub></span>.<br />Thus, if any <span class=\"tex-span\"><i>b</i><sub class=\"lower-index\"><i>i</i></sub></span> is either lower than <span class=\"tex-span\">2</span> or higher than <span class=\"tex-span\">2·<i>a</i><sub class=\"lower-index\"><i>i</i></sub></span>, then no <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span> and <span class=\"tex-span\"><i>y</i><sub class=\"lower-index\"><i>i</i></sub></span> can be found, thus, Sereja's joy will surely decrease by <span class=\"tex-span\">1</span>.</p><p>Amongst all pairs of <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/cb276cd4dc36f23b69b51abe41e17841282ed42c.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> that <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub> + <i>y</i><sub class=\"lower-index\"><i>i</i></sub> = <i>b</i><sub class=\"lower-index\"><i>i</i></sub></span>, the pair with the highest value of <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub>·<i>y</i><sub class=\"lower-index\"><i>i</i></sub></span> will be one with the equal value of <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub> = <i>y</i><sub class=\"lower-index\"><i>i</i></sub></span> (this can be proven by the famous AM-GM inequality).<br />Thus, if <span class=\"tex-span\"><i>b</i><sub class=\"lower-index\"><i>i</i></sub></span> is divisible by <span class=\"tex-span\">2</span>, we can easily pick <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/4ebbc716337dc5b987bc678f95685e3b6e874bfa.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />.<br />Also, from this, we can see (either intuitively or with static proofs) that the lower the difference between <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span> and <span class=\"tex-span\"><i>y</i><sub class=\"lower-index\"><i>i</i></sub></span> is, the higher the value <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub>·<i>y</i><sub class=\"lower-index\"><i>i</i></sub></span> will be. Thus, in case <span class=\"tex-span\"><i>b</i><sub class=\"lower-index\"><i>i</i></sub></span> being odd, the most optimal pair will be <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/4bc158af48fdad3d0dba7ead977ad08c6efd4343.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> or <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/443272cf5829fac4b5f9b1d92d3319449b0a967a.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> (the order doesn't matter here).</p><p>Time complexity: <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/e50d121c611e249696d85ac98167ee3dfa4ba3f3.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />.</p></div></div> <div class=\"spoiler\"><b class=\"spoiler-title\">Solution</b><div class=\"spoiler-content\" style=\"display: none;\"><p>Submission link: <a href=\"/contest/390/submission/48212208\" title=\"Посылка 48212208 от AkiLotus\">48212208</a></p> <div class=\"spoiler\"><b class=\"spoiler-title\">Source code in plain text</b><div class=\"spoiler-content\" style=\"display: none;\"><pre><code>#pragma GCC optimize("Ofast")\n\n#include <bits/stdc++.h>\nusing namespace std;\n\n#define endl '\\n'\nmt19937 rng32(chrono::steady_clock::now().time_since_epoch().count());\nmt19937_64 rng64(chrono::steady_clock::now().time_since_epoch().count());\n\nint main(int argc, char* argv[]) {\n\tios_base::sync_with_stdio(0); cin.tie(NULL);\n\t\n\tint n; cin >> n;\n\t\n\tvector<int> a(n), b(n);\n\tfor (auto &z: a) cin >> z;\n\tfor (auto &z: b) cin >> z;\n\t\n\tlong long Joy = 0;\n\tfor (int i=0; i<n; i++) {\n\t\tif (b[i] < 2 || b[i] > a[i] * 2) {Joy--; continue;}\n\t\tint x = b[i] / 2, y = b[i] - x;\n\t\tJoy += 1LL * x * y;\n\t}\n\tcout << Joy << endl;\n\t\n\treturn 0;\n}\n</code></pre></div></div></div></div><h2><a href=\"/contest/390/problem/C\" title=\"Codeforces Round 229 (Div. 2)\">390C - Инна и коробки с конфетами</a></h2> <div class=\"spoiler\"><b class=\"spoiler-title\">Approach</b><div class=\"spoiler-content\" style=\"display: none;\"><